Getting involved with any subject means getting to learn the language. Orchids, and plants in general, are no exception.
Listed below are a large number of terms which are commonly used in describing plants. Most of these terms have been published by
TheAmerican Orchid Sociey (AOS), and may be found on their web site.
Learning these terms, and their pronunciation, will enhance your appreciation, understanding. and ability to communicate with others.

Bletia ensifolia Clowesia russelliana Meiracyllium wendlandii

Definitions A-F Definitions G-L Definitions S-Z Color Definitions

Definitions M thru R

M  N  O  P  Q  R

Pronunciation Key

Pronunciation is based on the many variations of sound found in regional dialects both within a country and internationally. Pronunciation of the same Latin word by Americans, British, Italians, Spaniards, Japanese, etc. can sometimes be difficult to interpret. Below are vowels listed first, followed by a few consonants. With this guide, you should have little difficulty in sounding out the syllables as shown in the pronunciation guide.

Most terminology in this glossary, with the exception a few common English words, have a pronunciation guide in parentheses immediately following the word. In some cases alternate pronunciation is also shown.  Each syllable is separated by a hyphen. Syllables printed in CAPITALS are stressed, that is, the accent falls on these, while lower case syllables are not stressed.

a = a as in about
ab = ab as in absent
ad = ad as in advertise
af = af as in after
ag = ag as in aggravate
ah = a as in star
ak = ac as in active
al = al as in altitude
all = all as in fall
am = am as in amber
an = an as in ant
aw = aw as in saw
ay = ay as in say
i = i as in it
e = e as in often
ee = ee as in see
eh = e as in pet
eye = i as in pie
ew = ew as in few
o = o as in offer
oh = o as in bone
oo = oo as in soon
ow = ow as in how
oy = oy as in boy
u = u as in butter
uh - u as in medium
ff = ff as in stuff
g = g as in good
j = g as in ginger
k = k as in kite
s = s as in sing
ss = ss as in kiss
th = th as in thin
z = z as in zebra



For Latinized words the gender endings are also shown.

M
MACRANTHUS, -a, -um (ma-KRAN-thus) - Broad or large flowered.
MACROCERAS (ma-KROH-ser-us) or (mak-ro-SER-as) - Long-horned.
MACROCHILUS, -a, -um (ma-kroh-KY-lus) or (mak-ro-KYE-lus) - Broad or large lipped.
MACROPHYLLUS, -a, -um (mak-ro-FILL-us) - Large-leaved.
MACROSTACHIUS (ma-kro-STACK-i-us) - Having long spikes.
macrostachyus, -a, -um (mak-ro-STAY-kee-us) - Having long tails like an ear of corn.
MACULATE (MAK-u-late) - Marked with spots, blotched or mottled.
MACULATUS, -a, -um (mak-yew-LAY-tus) - Spotted; maculate.
MACULE (MAK-yule) - A spot of pigment; The color spot or mask on the base of the lip in Miltonias.
MACULOSUS, -a, -um (mak-yew-LOH-sus) - Spotted; maculate.
MAGNIFICUS, -a, -um (mag-NIF-i-kus) - Showy; magnificent.
MAGNUS, -a, -um (MAG-nus) - Great; large; big.
MAJALIS, -e (ma-JAY-lis) - Flowering in May.
MAJOR (MAY-jer) - Large compared to others of the same genus.
MAJUS, -a, -um (MAY-jus) - Large compared to others of the same genus.
MALATHION (mal-ah-THYE-on) - The common name for a chemical pesticide consisting of S-(dicarbethoxyethyl) - O, (O-dimethy dithiophosphate) -; used for the control of soft scales, spider mites, aphids and other orchid pests.
MALQUIQUE (mal-KEE-ke) - Mexican term for tree fern and for tree fern fiber.
MAMMIFORM (MAM-mih-form) - Conical with a rounded top; breast-shaped
MAMMILLATE (MAM-mil-late) - Having nipple-shaped processes.
MAMMILLATUS, -a,-um (mam-mil-LAY-tus) - Having nipple-shaped structures; mammillate.
MANICATUS, -a, -um (man-i-KAY-tus) - With long sleeves or sheaths.
MARBLED - Having irregular splashes or streaks of color.
MARCESCENT (mar-SES-ent) - Withering, but not falling off.
MARCOTTAGE (MAR-ko-tazh) - The method of vegetative propagation in which a ball of sphagnum moss is bound about the stem of a plant to furnish a congenial medium for the growth of roots.
MARGINALIS, -e (mar-jin-AY-lis) - Placed upon or attached to the edge.
MARGINATE (MAR-ji-nate) - Furnished with a margin or border of distinct character.
MARGINATUS, -a, -um (MAR-jin-ay-tus) - When the flat surface has an edge of a different color.
MARMORATE (MAR-mae-rate) - Variegated or lined like marble.
MARMORATUS, -a, -um (mar-mor-AY-tus) - Marbled; mottled; marmorate.
MATUTINUS, -a, -um (ma-too-TYE-nus) or (ma-TEW-tin-us) - Pertaining to or occurring in the morning; matutinal. Morning flowering.
MAXILLARIS, -e (MAKS-si-lay-ris) or (mak-sil-AIR-iss) - Resembling jaws.
MAXIMUS, -a, -um (MAK-si-mus) or (MAK-sim-us) - The largest of its group or kind; maximal.
MEALYBUG (MEE-lee-bug) - A group of sucking insects commonly found in the leaf axils and along the inflorescences of orchids, characterized by white elliptic bodies.
MEDIUM, MEDIA (MEE-dee-um, MEE-dee-a) - (1) A nutrient substance, either liquid or jelly-like, upon which orchid seeds are germinated under aseptic or sterile conditions. (2) The substance or substratum or material in which an orchid plant is grown under cultivation, either organic, such as osmunda, tree fern, bark, etc., or inorganic, such as gravel, cinders, pumice, etc.
MEDIUS, -a, -um (MEE-dee-us) - Intermediate; middle.
MEDUSAE (me-DEW-see) - Referring to Medusa, one of the Gorgons whose locks Minerva changed into serpents.
MEIOSIS (my-OH-sis) - The reduction division that halves the number of chromosomes.
MELEAGRIS, -re (MEL-ee-AY-gris) - Resembling or spotted like a Guinea fowl.
MEMBRANACEOUS (MEM-bray-NAY-shus) - Thin and pliable, often semient as many leaves.
MEMBRANACEUS, -a, -um (mem-bran-AY-shus) - Thin and semitransparent; skinlike; membranaceous.
MEMBRANOUS (MEM-bra-nus) - Pliable and thin, transparent and usually not green.
MENISCOIDAL (men-iss-KOY-dal) - Like a meniscus or disk; with the form of a watch-crystal.
MENTUM (MEN-tum) - A basal or chinlike projection in certain orchids, formed by the sepals and extended foot of the column.
MERICLONE (MER-i-clone) or (MAIR-i-klohn) - A plant derived from tissue culture that is identical to its parent. A clonal orchid plantlet produced through the technique of meristem propagation.
MERISTEM (MER-i-stem) or (MAIR-i-stem) - Embryonic or undifferentiated tissues, the cells of which are capable of active division. The actively growing tissue of a plant, used for artificial cloning. The growing tissue made up of actively dividing cells, particularly at the tips of roots and at the apex of the vegetative or floral shoot.
-MEROUS (mer-uhs) - A suffix meaning having parts, as three-merous; having three parts of each kind.
MESIC (mes-IK) - Constantly moist.
MESOCARP (MES-oh-karp) - Middle layer or part of a pericarp; the part between the endocarp and exocarp.
MESOCHILE (ME-so-kile) or (MES-oh-kyle) - The central portion of the labellum in certain orchids. The intermediate or middle part of the lip of orchids whose lip is separated into three parts.
MESOPHYLL (MES-o-fill) - This thin walled cell tissue of a leaf-blade; a photosynthetic tissue, concerned with the gaseous exchange with the atmosphere.
MESOPHYTE (MES-o-fite) - Plant growing under average conditions of moisture and in a temperate climate. A plant that only requires an average amount of water.
METER (MEE-ter) - A measure of length equal to 39.37 inches or 10 decimeters; abbreviated m.
MICROCHILUS, -a, -um (MY-kro-ky-lus) - Small-lipped.
MICROPROPAGATION (mye-crow-prop-a-GAY-shun) - The horticultural propagation of plants by in vitro multiplication by tissue culture (meristemming) and sterile seed culture.
MICROPYLE (MYE-kroh-pyle) or (MY-kro-pile) - The opening of the ovule through which impregnation takes place; the point on the seed marking the orifice of the ovule.
MIDRIB - The main vein of a leaf or leaflike part.
MILITARIS, -e (mil-i-TAY-ris) - Pertaining to soldiers; like a soldier. In plants often in reference to flowers carried stiffly erect like soldiers.
MILLIMETER (mill-ih-MEE-ter) - A measure of length equal to .03937 of an inch (1/25 of an inch); abbreviated mm. one one-thousandth of a meter
MINAX (MYE-naks) - Threatening; forbidding.
MINIATUS, -a, -um (min-ee-AY-tus) - Vermilion-colored; cinnabar-red; miniaceous.
MINIMUS, -a, -um (MIN-i-mus) - Smallest; minimum.
MINUS, -a, -um (MYE-nus) - Smaller.
MINUTISSIMUS, -a, -um (mye-new-TISS-i-mus) - The smallest; most minute.
MINUTUS, -a, -um (mye-NEW-tus) - Very small; minute.
MIRABILIS, -e (mye-RAB-il-is) - Wonderful; remarkable; marvelous.
MITICIDE (mye-TIH-side) - A pesticide used to kill mites.
MITOSIS (my-TOE-sis) - The usual, and more complex, of the two methods in which cells of animals and plants multiply. The process of nuclear division producing daughter nuclei with the same number of chromosomes, followed by cell division; see meiosis.
MITRATUS, -a, -um (mye-TRAY-tus) - Wearing a miter, alluding to the shape of the flower.
MITRIFORMIS, -e (mye-tri-FOR-miss) - Miter-shaped, or like a cap.
MODESTUS, -a, -um (moh-DESS-tus) - Modest; not showy or flamboyant.
MONANDROUS (moh-NAN-drus) - With one stamen.
MONILIFORM (mo-NIL-i-form) - Constricted at intervals along its length; like a string of beads.
MONILIFORMIS, -e (mo-NIL-i-form-is) or (mo-nil-i-FOR-miss) - Necklace-like; having alternate swellings and constrictions.
MONO- (mon-oh) - A prefix meaning one
MONOCLINOUS (mon-oh-KLYE-nus) - Hermaphroditic; perfect; the two sexes in the same flower. (See diclinous)
MONOCOTYLEDONEAE (mon-oh-kot-ill-ee-DOHN-ee-ee) - One of two subclasses of the angiospermous (seeds in a closed ovary) plants having but one cotyledon (seed-leaf), a stem that rarely exhibits secondary growth in thickness and is without annual rings, leaves generally parallel-veined, and the flowers trimerous (having parts in threes); comprising such families as the orchids, lilies, irises, palms, sedges and grasses.
MONOCOTYLEDONS (mon-o-kot-i-LEE-duns) - Any seed plant having a single cotyledon or seed leaf.
MONODELPHOUS (mon-oh-DEL-fus) - When stamen filaments are fused into a column or tube.
MONOECIOUS (mo-NEE-shus) or (mon-EE-shus) - With unisexual flowers of both sexes appearing in one plant. With functional stamens and pistils in separate flowers on the same plant.
MONOGYNOUS (mon-NOJ-i-nus) - With only one style.
MONOMORPHIC (mon-o-MOR-fik) - In mycology, producing spores of one kind or form.
MONOPETALOUS (mon-oh-PET-a-lus) - One-petaled; all the petals united to form one body or organ, as a gamopetalous corolla.
MONOPHYLETIC (mon-o-FILE-e-tik) or (mon-oh-fye-LET-ick) - Derived from a single ancestrial line. A taxonomic and cladistic term referring to a group having a common ancestor.
MONOPHYLLOUS (mon-o-FILL-us) - Composed of a single leaf as opposed to bifoliate. Having a single leaf.
MONOPHYLY– having a single common ancester relating all members of the clade
MONOPODIAL (mon-oh-POH-dee-al) or (mono-PO-di-al) - A form of growth in which there is a single vegetative shoot that continues in growth from its terminal bud from season to season, such as in the genus Vanda. With growth continuous from a terminal upright leader. Orchids which grow upward from a single stem producing leaves and flowers along that stem.
MONOPODIUM (mono-PO-di-um) - A single axis from which all lateral branches rise.
MONOSTICHOUS (mo-NOS-ti-kus) - Arranged in a single row, or on one side of an axis.
MONOTYPIC (mon-oh-TIP-ik) or (mo-no-TIP-ik) - Having only one type. a genus with one species.
MONSTROSITY (mon-STROSS-i-tee) - Deformity; any unusual or atypical kind of development; a teratology.
MONTANUS, -a, -um (mon-TAY-nus) - Pertaining to or living in mountains; montane.
MORPHOGENESIS (mor-foh-JEN-eh-sis) - The process through which an embryo or cultured tissue develops into the final adult form.
MORPHOLOGY (mor-FOL-o-ji) - The branch of biology which deals with the form and structure of plants and animals without regard to functional processes.
MOSCHATUS, -a, -um (mos-KAY-tus) - Musk-scented.
MOSCIFERA (ma-SKIFF-er-a) or (mohs-ki-FER-a) - Bearing flies; alluding to the resemblance of some flowers to a fly.
MUCILAGINOUS (mew-suh-LAJ-uh-nuhs) – Mucilage-like or slimy
MUCOSUS, -a, -um (mew-KOH-sus) - With a slimy covering or secretion.
MUCRO (MEW-kro) - A short and small abrupt tip.
MUCRONATE (MEW-kro-nate) - Ending abruptly in a sharp point.
MUCRONATUS, -a, -um (mew-kron-AY-tus) - Tipped with a mucro; pointed; mucronate.
MUCRONULATUS, -a, -um (mew-KRON-ule-aye-tus) - Having a small mucron, or sharp, pointed tip, used to describe the leaf apices of many orchids.
MULE - An old term for a hybrid cross, particularly between different species; a hybrid.
MULTIFLORUS, -a, -um (mul-tee-FLOR-us) - Many-flowered.
MULTIGENERIC (MUL-tee-jen-AIR-ik) - A plant that has resulted from crossing several genera.
MULTISERIATE (MUL-tee-SER-ee-ate) - arranged in rows or layers
MURALIS, -e (mew-RAY-lis) - Growing on walls.
MURICATE (MU-ri-kate) - With sharp points or prickles. Studded with short rough points.
MURICATUS, -a, -um (mew-ri-KAY-tus) - Roughened with short, hard prominences; muricate.
MUSCARIFORMIS, -e (mus-ka-ree-FOR-miss) - In the form of a brush or flybrush.
MUSCOSUS, -a, -um (mus-KOH-sus) - Resembling a moss.
MUTABILIS, -e (mew-TAB-il-is) - Changeable, especially as to color.
MUTANT - An individual resulting from a mutation.
MUTATION (mu-TAY-shun) - Alteration of the chromosomal material. A change in the amount of chemical structure of DNA, resulting in a change in characteristics of a cell or organism; an individual resulting from such a change.The majority of mutations are changes of individual genes.
MUTICOUS ( mew-TEE-kos) - Blunt or pointless.
MUTICUS, -a, -um (MEW-tik-us) - Blunt; without a point.
MYCELIUM (my-SEE-li-um) or (mye-SEE-lee-um) - Vegetative part of a fungus, composed of threads or thready tissue (hyphae).
MYCORRHIZA (mi-ko-RYE-za) or (my-koh-RHYZ-ah) - a fungus that invades the root tissues and forms a symbiotic relationship with it. The fungus digests organic matter, making it easier for the plant to absorb, and the fungus is assured access to moisture. The condition of having symbiotic fungi associated with roots, the usual condition in orchids as well as other plant families such as the Ericaceae, or heath family.
MYRIANTHUS, -a, -um (meer-ee-AN-thus) or (mir-i-AN-thus) - Innumerable-flowered.
MYRMECOPHILOUS (mer-me-KOFF-ill-us) - Ant-loving; inhabited by ants.

N
NAEVIUS, -a, -um (NEE-vi-us) - Freckled.
NACREOUS (NAY-kree-us) – Iridescent, pearlescent or lustrous.
NAKED - Wanting its usual covering or lacking certain organs as leaves, pubescence, etc.
NANELLUS, -a, -um (nan-ELL-us) - Very dwarf.
NANUS, -a, -um (NAY-us) - Dwarf.
NAPIFORMIS, -e (nap-i-FOR-miss) - Turnip-shaped; more or less short-fusiform; broader than high and abruptly tapering both ways; napiform.
NASCENT (NAY-scent) - In the process of being formed, as in meristematic tissue
NASUTUS, -a, -um (nas-OO-tus) - Large-nosed.
NATANS (NAY-tanz) - Floating.
NATURAL HYBRID - A hybrid produced in the wild, in contrast to an artificial hybrid produced by man.
NATURAL SELECTION - The process of evolution that results in the differential survival and reproduction of those individuals best adapted to their environment.
NATURALIZED (NACH-er-uhl-eyzd) - Said of plants from foreign areas that have become established.
NAVICULAR (na-VIK-yew-lar) - Boat-shaped; cymbiform.
NAVICULARIS, -e (nav-ik-yew-LAY-ris) - Boat-shaped; cymbiform; navicular.
NEBULOSUS, -a, -um (neb-yew-LOH-sus) - Clouded; cloudlike; also applied to a plant found growing at a high elevation.
NECROTIC (nec-ROT-ik) - The condition of cells and tissues killed through disease or injury.
NECTAR (NEK-tar) - The saccharine secretion of a plant which attracts the insects that pollinate the flower.
NECTAREOUS (nek-TAR-e-us) - Resembling nectar.
NECTARIFEROUS (nek-tar-IF-er-us) - Having nectar. Nectar-bearing.
NECTARY (NEK-tar-ee) - A nectar secreting organ or part, such as the spurs of many orchids.
NEGLECTUS, -a, -um (neg-LEK-tus) - A plant hitherto disregarded or overlooked.
NEMORALIS, -e (nem-oh-RAY-lis) - Growing in groves or shady places; nemoral.
NEO- (NEE-oh) - A prefix meaning new.
NEOTROPICAL (NEE-o-TROP-i kal) or (nee-oh-trop-ih-kuhl) - Of, pertaining to or designating the region comprising South America, the West Indies and tropical North America.
NEPHROID (NEF-roid) - Kidney-shaped, reniform.
NERVATION (ner-VAY-shun) - See venosus.
NERVE - A vein or slender rib, particularly if not branched.
NERVOSE (NUR-vose) - Sinewy, vigorous, prominently nerved.
NERVOSUS, -a, -um (ner-VOH-sus) - Prominently nerved; nervose.
NETTED (net-ed) - Marked with reticulated lines or veins.
NEUTER - Said of a flower lacking reproductive structures.
NEUTRAL - A chemical condition of water or moist soil in which acid and alkaline constituents are exactly balanced; pH 7.
NIDULATUS, -a, -um (nid-yew-LAY-tus) - Nested; like or borne in a nidus or nest; nidulate.
NIGER, nigra, nigrum (NYE-jer) - Black.
NIGRESCENS (nye-GRESS-enz) - Blackish; nigrescent.
NITENS (NYE-tenz) - Shining; becoming shiny.
NITIDUS, -a, -um (NIT-id-us) - Shining, lustrous, bright.
NITRIFICATION (NYE-tri-fi-KAY-shun) - Conversion of organic nitrogen compounds in soil to inorganic compounds (as ammonium salts or as nitrates) available to plants by the cumulative action of a succession of soil micro-organisms.
NIVALIS, -e (niv-AY-lis) - Snowy white; nival.
NIVEUS, -a, -um (NIV-ee-us) - Snowy; snow-white; growing near snow.
NOBILIS, -e (NO-bee-leez) or (NOH-bil-is) - Remarkable for fine qualities; noble..
NOCTURNAL (nok-TER-nuhl) - Of the night; used in reference to flowers that open after dark or having fragrance only at night.
NOCTURNUS, -a, -um (nok-TUR-nus) or (nok-TERN-us) - Night-flowering; Night blooming.
NODE - A joint on a stem or pseudobulb from which a leaf or growth originates.
NODOSE (NOH-dose) - Knobby or knotty.
NODOSUS, -a, -um (noh-DOSE-us) or (noh-DOH-sus)  - Having many joints or nodes knotty; knobbed;. nodose.
NODULE (nah-dewyl) - A small node
NOMENCLATURE (noh-men-CLAY-chure) or (NOH-men-klay-cher) - Names referring individuals to groups of related members according to a binomial system. A set or system of names and naming.
NOTATUS, -a, -um (noh-TAY-tus) - Spotted; marked.
NUBIGENUS, -a, -um (new-bi-JEN-us) - Born among the clouds; from a high elevation.
NUCLEOLUS (noo-klee-OH-lus) - The central denser structures of a cell. A sharply defined point in the nucleus of a cell where ribosomal RNA is synthesized.
NUCLEUS (NEW-klee-us) - The central dense structure of a cell where DNA is replicated and transcribed.
NUDUS, -a, -um (NEW-dus) - Naked; bare; nude.
NUTANS (NEW-tanz) - Nodding; nutant.
NUTRIENT - A chemical needed for growth, or a substance providing such.
NUTRIENT SOLUTION A water solution of chemicals or natural substances required for growth or germination.
NUTRITION - The act or process by which an organism obtains energy and chemicals from the environment for survival or growth.

O
OB- (ob) - A prefix meaning inversely or oppositely.
OBCOMPRESSED (ob-kuhm-PREST) - Flattened dorso-ventrally, instead of laterally
OBCONICAL (ob-KON-i-kuhl) - Inversely conical; having the attachment at the apex.
OBCORDATE (ahb-CORD-ate) - Heart-shaped with the attachment at the apex; inversely cordate.
OBCORDATUS, -a, -um (ahb-kor-DAY-tus) - Inversely cordate; heart-shaped with the attachment at the apex, obcordate.
OBLANCEOLATE (ohb-LAN-see-o-late) or (ob-LAN-see-oh-layt) - Shaped like a lance, point reversed, that is, having the tapering point next to the leafstalk.
OBLATUM (ob-LAY-tum) - an oblate spheroid. (See Ellipsoid)
OBLIQUE (ob-leek) - Having unequal sides; asymmetrical; slanting.
OBLIQUE (ob-LEEK) - Of a leaf or leaflet, larger on one side of the midrib than on the other, i.e. asymmetrical.
OBLONG - Having the length greater than the width but not many times greater, and the sides nearly parallel.
OBLONGIFOLIUS, -a, -um (ob-long-gi-FOH-lee-us) - With oblong leaves.
OBOVATE (ob-OH-vate) or (ob-OH-vayt) - Inversely ovate; inversely egg-shaped; egg-shaped with the narrower end at the base. Usually used in describing a leaf.
OBOVOID (ob-OH-voyd) or (OB-oh-void) - Inversely ovoid; egg shaped with the narrow end at the base.
OBPHYRIFORM (ob-PIR-i-form) - Having the form of an inverted pear.
OBRYZATUS, -a, -um (oh-bry-ZAY-tus) - Pure gold color.
OBSOLESCENT (ob-suh-LES-uhnt) or (OB-soh-LES-ent)  - Becoming rudimentary; gradually disappearing or imperfectly developed.
OBSOLETE (OB-so-leet) - Rudimentary or not distinct. Imperfectly developed.
OBTRIANGULAR (Ob-try-ang-you-lar)- like an upside down triangle
OBTUSE (ob-TUSE) - Blunt or rounded as a leaf with a wide apex.
OBTUSIFOLIUS, -a, -um (ob-too-si-FOH-lee-us) - Blunt-leaved.
OBTUSUS, -a, -um (ob-TOO-sus) - Blunt or rounded at the tip; having an angle greater than 90 degrees.
OBVATE (see OBOVATE).
OCELLATUS, -a, -um (oh-sell-LAY-tus) - With an eye; having a circular spot of one color inside a larger spot or area of another color.
OCHRACEUS, -a, -um (oh-KRAY-see-us) - Yellowish, ocher-colored; ochraceous.
OCHROLEUCOUS (oh-kro-LEW-kus) - Yellowish white
OCREATE (oh-KREE-ayt) - Having stipules that sheath.
OCULATE (OK-u-late) - Having spots or holes resembling eyes.
OCULATUS, -a, -um (ok-yew-LAY-tus) or (OK-u-la-tus) - Having one or more dark spots resembling eyes; oculate.
OCULUS (OK-yew-lus) - An eye; a leaf bud used as a cutting.
ODONTOCHILUS, -a, -um (oh-don-toh-KYE-lus) - Having a toothed lip. Also a genus of terrestrial orchids from Asia and the Pacific.
ODORATISSIMUS, -a, -um (OH-dor-a-TISS-i-mus) or (oh-door-a-TISS-i-mus) - Very fragrant.
ODORATUS, -a, -um (oh-dor-AY-tus) or (oh-do-RAY-tus) - Fragrant.
OFFICINALIS, -e (oh-fiss-in-AY-lis) - Kept in stock by apothecaries. Typically refers to species of ethnobotanical interest.
OFFSET (AWF-set) - A short lateral shoot that may produce another plant; an offshoot.A plant arising close to the base of mother plant. Synonym: keikei.
OLEAGINOUS (oh-lee-AJ-in-us) - Having the nature or quality of oil.
OLIGANTHIS, -a, -um (ol-ig-ANTH-us) - With few flowers.
OLIVACEUS, -a, -um (ol-iv-AY-see-us) - Greenish brown; olive-colored; olivaceous.
ONCIDIODES (on-sid-ee-OH-eye-dees) or (on-sid-ee-OY-deez) - Resembling an Oncidium.
ONTOGENY (on-TOJ-e-ni) - Development cycle of an organism or organ. The process of development of an organ toward maturity.
OPAQUE (o-PAKE) - Dull; Neither shiny nor translucent.
OPERCULATE (o-PUR-ka-late) or (oh-PERK-yew-layt) - Lid-like, as some anthers, or furnished with a lid.
OPERCULUM (o-PUR-ka-lum) or (oh-PERK-yew-lum) - A cap or lid to an organ shedding by circumscissle dehiscence; in orchids, the anther cap.
OPPOSITE - Said of a plant having two leaves at the same node; attached to the stem in pairs, on opposite sides of the node.
ORBICULAR (or-BIK-u-lar) - Circular.
ORBICULARIS, -e (or-bik-yew-LAY-ris) - Having a rounded outline; disc-shaped; orbicular.
ORBICULATE (or-BIK-u-late) - Circular.
ORBICULATUS, -a, -um (or-bik-yew-LAY-tus) - Disc-shaped; orbiculate.
ORCHIDACEAE (or-ki-DAY-se-ee) - The large family of perrenial epiphytes and terrestial plants, considered the most highly developed of the monocotyledons.
ORCHIDALES (or-ki-DAY-lees) - A Lindleyan alliance including the orchids.
ORCHIDIST (OR-ki-dist) or (ore-KID-ist) - One whose interest in orchids is primarily horticultural.
ORCHIDOLOGIST (orki-DOL-o-jist) - One who specializes in the study of orchids, particularly their evolution and relationships.
ORCHIDOLOGY (ore-KID-oll-uh-gee) - The branch of technical botany that deals with orchids and their study.
ORGANELLE (ore-GAN-ell) - An organized structure within the cell that has a specialized function.
ORIFICE (OR-i-fis) or (ore-uh-FISS) - An opening.
ORIGINATOR - In reference to the registration of an orchid hybrid, the owner (or his assignee) of the seed-bearing parent at the time of pollination.
ORNITHORHYNCHUS, -a, -um (or-ni-tho-RIN-kus) or (or-nith-oh-RINK-us) - Resembling the beak of a bird.
ORTHO- (or-tho) - A prefix element meaning "straight" or "upright."
OSMOSIS (os-MOS-sis) - Diffusion of water through a membrane which is selectively permeable to water. Diffusion of a solvent such as water through a semipermeable membrane from a dilute to a concentrated solution.
OSMUNDA (os-MUN-da) - A genus of swamp fern forming large clumps or crowns.
OSMUNDINE (os-MUN-deen) or (oz-MUN-deen) - Osmunda fiber. The root system of the royal fern or cinnamon fern, used in potting orchids. The cut fibrous roots of ferns of the genus Osmunda used as a growing medium for epiphytic orchids; osmunda.
OVALIS, -e (oh-VAY-liss) - Broadly elliptic in shape; oval.
OVARY (OH-va-ri) or (OH-vah-ree) - The part of the pistil of a flower that contains the ovules (young seeds). The swollen part of a female organ. The part of an orchid flower that becomes the fruit following pollination and fertilization. It contains the ovules, which, if fertilized, become the seeds; in orchids, the ovary is combined with the pedicel to form the pedicellate ovary beneath the flower.
OVATE (OH-vate) - Shaped like an egg in two dimensions, and attached by the wider end.
OVATUS, -a, -um (oh-VAY-tus) - Shaped like the outline of an egg, with the broader end downward; ovate.
OVERPOT (OH-ver-pot) - To pot an orchid in a container larger than necessary, allowing more freedom for root growth or for greater plant growth, or allowing for a greater time interval before repotting; in inexperienced hands, this can be detrimental to the plant.
OVERWATER (OH-ver-wah-ter) - To keep the medium too wet or too damp, usually degrading the roots and eventually preventing the plant from absorbing needed water and nutrients.
OVOID (OH-void) - Shaped like an egg, with the broader end downward. Egg shaped, the larger end toward the stem or axis; used in a three-dimensional sense as opposed to ovate.
OVULATE (OV-yuh-layt) - Bearing ovules
OVULE (OH-vule) - One of the young bodies in the ovary that, upon fertilization, develop into a seed; the female gametophyte. One of the young bodies in the ovary which, upon fertilization, develop into seed; structure bearing megaspores, the site of egg cell formation and finally the site of embryo development.
OVULIFEROUS (OH-voo-LIF-er-us) - Ovule-bearing.
OVULIFERUS, -a, -um (oh-vyew-LIF-er-us) - Ovule-bearing.

P
PACHYCAUL (PA-ki-caw`l) - An abnormally thick-stemmed plant.
PACHYPHYLLUS, -a, -um (PA-ki-FIL-lus) or (pak-ee-FILL-us) - Thick leaved.
PALLENS (PAL-lenz) - Becoming pale or light in color.
PALLIDUS, -a, -um (PAL-li-dus) - Pale, pallid.
PALMATE (PAL-mate) - Lobed, radiating like fingers.
PALMATUS, -a, -um (pal-MAY-tus) - Lobed and radiating like the fingers; palmate.
PALUDOSE (PAL-oo-dose) - Growing in marshes.
PALUDOSUS, -a, -um (pal-yew-DOH-sus) - Growing in marshes; paludose.
PALUSTRIS, -e (pal-US-triss) - Growing in marshes; palustrine.
PAN - A form of pot that is broader and shallower than the regular type. These are also known as azalea pots or bulb pans.
PANDURATE (pan-DUR-ate) - Shaped like a violin; oblong.
PANDURATUS, -a, -um (pan-dew-RAY-tus) - Shaped like a violin; pandurate.
PANDURIFORM (pan-DUR-i-form) - Fiddle-shaped.
PANDURIFORMIS, -e (pan-dew-ri-FOR-miss) - Fiddle-shaped; panduriform.
PANICLE (PAN-i-k'l) or (PAN-i-kul) - A compound raceme or branched cluster of flowers. A pyramidal form of inflorescence, in which the cluster is loosely branched below and gradually simpler toward the end. A loosely arranged branched inflorescence, blooming from the center or lower branches to the outer ends or top.
PANICULATE (pan-I-kew-late) or (pan-IK-yew-layt) - Arranged in panicles. Indeterminate and much branched. Having an inflorescence resembling a panicle.
PANICULATUS, -a, -um (pan-ik-yew-LAY-tus) - With flowers arranged in a paniculate manner.
PANNOSE (pan-noze) - Having the texture of felt or woven cloth.
PAPILIONACEOUS (pa-PIL-i-a-NAY-shus) - Having an irregular corolla shaped somewhat like a butterfly.
PAPILLA (pa-PEE-la) - A small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.
PAPILLAE (pa-PILL-ee) - Minute nipplelike projections.
PAPILLOSE (pa-PEE-los) - Covered with, or bearing, papill[ae]
PAPILLOSUS, -a, -um (pap-ill-OH-sus) - Covered with nipple-like protuberances on the surface; papillose.
PAPYRACEOUS (pa-pee-RAY-shus) - paperlike
PARAPHYLETIC (pair-ah-fy-LET-ick) - Cladistic term for a group that does not include all descendants of a common ancestor.
PARASITE (PAR-a-site) - A plant dependent on another plant (the host) for its nutrition.
PARDINUS, -a, -um (par-DYE-nus) - Spotted like a leopard or panther.
PARENCHYMA (puh-RENG-kuh-muh) - Said of undifferentiated cells with thickened walls.
PARENT - One of the two particular plants responsible for the production or generation of a given plant or progeny.
PARIETAL (pa-RYE-e-tal) - Borne on the inner surface or wall surface of a capsule or ovary.
PARTED - Cleft or cut almost to the base.
PARTHENOCARPY (par-then-o-CAR-py) - Development of fruit without fertilization and seed formation.
PARTHENOGENESIS (par-then-I-o-JEN-I-sis) or (par-thin-oh-JEN-e-siss) - Phase of development in which the egg-cell of a diploid gametophyte divides without fertilization. Plants so formed are maternal in genetic constitution. The process by which a seed may develop without fertilization; plants so produced have the genetic constitution of the seed-bearing plant.
PARTITIONED (par-TISH-und) - Divided in compartments or chambers by internal horizontal walls.
PARTITUS, -a, -um (par-TYE-tus) - Divided nearly to the base; partite.
PARVIFLORUS, -a, -um (PAR-vi-FLOR-us) - Small flowered.
PARVUS, -a, -um (PAR-vus) - Small.
PASSERINUS, -a, -um (pass-er-EYE-nus) - Resembling or marked like a sparrow; passerine.
PATELLIFORM (pah-TELL-ih-form) - In the shape of a disc.
PATENS (PAY-tenz) - Spreading.
PATENT (pah-TENT) or (PA-tent) - flat to spreading; Expanded.
PARTHENOCARPY (par-then-o-CAR-py) - Development of fruit without fertilization and seed formation.
PATHOGEN (PATH-oh-jen) - A disease-producing organism.
PARTHENOGENESIS (par-then-I-o-JEN-I-sis) - Phase of development in which the egg-cell of a diploid gametophyte divides without fertilization. Plants so formed are maternal in genetic constitution.
PARVIFLORUS (PAR-vi-FLOR-us) - Small flowered.
PATENT (pah-TENT) - flat to spreading
PATHOGEN (PATH-oh-gen) - A disease producer.
PATHOLOGICAL (path-oh-LOJ-i-cal) or (path-oh-LOJ-i-kul) - Diseased.
PATHOLOGY (path-OLL-oh-jee) - The science dealing with diseases, their causes, results and cures.
PATULOUS (PAT-u-lus) - Spreading, broad, loosely expanded.
PATULUS, -a, -um (PAT-yew-lus) - Spreading, broad, flat; patulous.
PAUCUS, -a, -um (PAW-kus) - Few. In compound words pauci-
PEAT (peet) - Any mass of semicarbonized vegetable tissue formed by a partial decomposition in water of various plants, especially species of the moss genus Sphagnum.
PECTINATUS, -a, -um (pek-ti-NAY-tus) - Shaped like a comb, with narrow parallel projections; pectinate.
PEDALIS, -e (ped-AY-lis) - About one foot long.
PEDATUS, -a, -um (ped-AY-tus) - Like a bird's foot; footlike; pedate.
PEDICEL (PED-i-sel) - The stalk of a flower. a small stalk bearing a single flower of an inflorescence; an ultimate division of a common peduncle; in orchids usually continuous with the inferior ovary.
PEDICELLATE (PED-i-se-late) - Borne on a pedicel, or like a pedicel.
PEDICELLATE OVARY (PED-i-sel-layt OH-va-ree) - In orchids, the combined pedicel with the ovary of the flower.
PEDUNCLE (pe-DUN-krl) or (pe-DUNK-ul) - Stalk of a flower cluster or an individual flower when that flower is the sole member of the inflorescence. The stem or stalk that supports the flower or fruit of a plant, or a cluster of flowers or fruits.
PEDUNCULARIS, -e (pe-DUN-koo-lar-is) or (pe-dunk-yew-LAY-riss) - Having long peduncles or flower stalks.
PEDUNCULATUS, -a,-um (pe-dunk-yew-LAY-tus) - Borne on a peduncle; pedunculate.
PELLICLE (PELL-i-kuhl) - An epidermis or surface membrane.
PELLUCID (pe-LOO-sid) or (pel-LOO-sid) - Clear or transparent.
PELORIA (pe-LOR-I-a) or (pe-LOR-ee-a) - Abnormal regularity of structure occurring in flowers normally irregular; generally applied to orchids where the petals have lip characters or colors. Also when lips take on petal characteristics.
PELORIC (pe-LOR-ik) - Having peloria; abnormally regular or symmetrical – applied to flowers.
PELTATUS, -a, -um (pel-TAY-tus) - Shield-shaped; peltate.
PENDENT (PEN-dent) - supported from above; Hanging down; "fuchsias in hanging pots"; "pendent bunches of grapes"; dangling, hanging, suspended.
PENDULUS, -a, -um (PEN-doo-lus) - Hanging or drooping; pendulous.
PENNATUS, -a, -um (pen-AY-tus) - Feathered.
PENTADACTYLUS, -a, -um (pen-tah-DAK-til-us) or (pen-TA-dak-to-LUS) - Five fingered. pentadactyl; pentadactylate.
PENTAMEROUS (pen-TAM-er-us) - Consisting of or divided into five parts.
PENTAPLOID (PEN-ta-ploid) - Having five sets of chromosomes. (5N)
PENTAS- (pen-tus) - Greek prefix meaning five.
PERBELLUS, -a, -um (per-BELL-us) - Very beautiful.
PERCUSSUS, -a, -um (per-KUSS-us) - Perforated, or appearing so.
PERENNIAL (per-ENN-ee-al) - Having a life cycle lasting more than two years.
PERFECT - Said of flowers that have both the staminate (male) and pistillate (female) parts.
PERFOLIATE (per-FOLL-ee-ayt) - Said of stems that pass through a leaf.
PERGAMENEOUS (per-gah-MEN-ee-us) - Having the texture of parchment.
PERGAMENTACEOUS (pur-gam-men-TAY-shus) - Texture of parchment.
PERI- (PEE-ri) or (PARE-ee) - A prefix derived from the Greek, signifying "around," "about," "beyond" in scientific terms.
PERIANTH (PER-i-anth) or (PARE-ee-anth) - The floral envelope considered as a whole, whether the calyx or corolla or both. The parts of a flower that enclose the sexual organs in the bud, normally the corolla (the combined petals) and the calyx (the sepals).
PERIANTH SEGMENTS - The sepals and petals considered separately.
PERICARP (PEAR-i-karp) - The ripened ovary. The outer ovary wall.
PERIPHERAL (puh-RIF-er-uhl) - Near the edge or margin
PERISPERM (PEAR-i-spurm) - Nutritive tissue accessory to endosperm. External skin of seed.
PERLITE (purr-LITE) - A lightweight, heat-expanded phosphate rock used to add aeration to potting media.
PERSISTENT (puhr-siss-tent) - Remaining for a long time, as leaves or flowers on the plant.
PERTUSUS, -a, -um (per-TEW-sus) - Perforated; having an aperture.
PERUVIANUS, -a, -um (per-ROO-vee-ay-nus) - Native of Peru; Peruvian.
PERVULENT (PURR-va-lent) - humped
PESTICIDE (PESS-ti-cyde) - General term for any chemical used to kill or control pests (e.g., fungicide, insecticide, herbicide)
PETAL (PET-al) - Unit of a corolla typically laminar, considered a sterile stamen; inner segments of perianth. In Orchids, one of the three petals is usually modified into a lip or labellum.
PETALOID (PET-al-OID)  or (PET-a-loyd) - Resembling a petal, as a petal-like sepal.
PETIOLATE (PET-i-o-late) - Having a petiole.
PETIOLATUS, -a, -um (pet-ee-oh-LAY-tus) - Having a petiole; petiolate.
PETIOLE (PET-i-ole) - A leaf stalk. The stalk portion of a leaf. The stalk by which a leaf is attached to a stem.
PETIOLULE (PET-i-o-lool) - Individual stalk of a leaflet.
pH - The chemical symbol representing the negative log of the hydrogen ion concentration as an indicator of acidity of a solution, pH 7.0 being neutral, acidity under 7.0 and alkalinity over 7.0.
PHENOGAM, PHENEROGAM (FEE-noh-gam) or (FEE-ner-oh-gam) - Flowering plants; seed-bearing plants (as distinguished from spore-bearing, or cryptogams)
PHENOGAMOUS (fee-NOG-am-us) - Plants as distinguished from spore-bearing cryptogams.
PHENOLOGY (fee-NOL-o-ji) - Part of ecology concerned with correlation of climatic factors with the vegetative and reproductive development of a plant.
PHENOTYPE (FEE-no-type) - A term referring to a group of individuals having similar external characteristics but differing in genetic composition. The external expression of a genotype.
PHILIPPINENSIS (fill-ip-pin-EN-sis) - Native of the Philippines; Philippine.
PHLOEM (FLOH-em) - The food conducting tissue within the vascular system of the plant.
PHOENICIUS, -a, -um (fee-NISH-us) - Purple-red.
PHOTOCHROME (fo-to-KROME) - A protein substance related to the flowering process. (Also - A color photograph.)
PHOTOPERIODISM (fot-toh-PEER-i-od-izm) or (foh-toh-PEER-ee-oh-dizm) - Response of the plant to length of daily exposure to light. Correct duration, combination of light and dark periods for production of flower producing hormones. The response of a plant to the daily duration of daylight, correlated to seasonal changes.
PHOTOSYNTHESIS (foh-toh-SIN-thee-sis) or (foh-toh-SIN-the-siss) - The process a plant uses to produce carbohydrates and sugar from water and carbon dioxide in the air using chlorophyl-containing cells exposed to light.
PHOTOTROPISM (foh-TOT-ro-pizm) - Growth response to light, either positive when vegetative parts bend or reach towards light, or negative when turning away from light (as roots).
PHYLLODIUM (pl. phyllodia) - (FILL-oh-dee-um, FILL-oh-dee-a) - A dilated petiole that resembles a leaf.
PHYLLOTAXY (fil-ah-TAK-si) or (FILL-oh-tak-see) - Leaf and flower arrangement on a stem. The arrangement of leaves on the stem.
PHYLLUM (FILL-um) - In compound words meaning leaf, as in aphyllum meaning "without leaves."
PHYLOGENETIC (fye-loh-je-NET-ik) - Pertaining to the evolutionary history of a type or group of organisms; the evolutionary system of a type or group of organisms.
PHYLOGENETICAL (phye-loh-je-NET-i-kal) - Pertaining to the race history of a type or group of organisms
PHYLOGENY (fye-LOJ-e-ni) or (fye-LOJ-en-ee) - Evolutionary development of a population, organism, organ or tissue.
PHYLUM (FYE-lum) - A primary division of the animal or vegetable kingdom.
PHYMATOCHILUS, -a, -um (fye-mat-oh-KYE-lus) - Having a swelling on the lip.
PHYTOLOGY (fye-TOL-oh-ji) - The study of plants; particularly of the kinds or species;. Botany.
PHYTOTOXICITY (fye-toh-tok-SISS-i-tee) - Poisonousness to plants.
PICTURATUS, -a, -um (pik-tew-RAY-tus) - Variegated.
PICTUS, -a, -um (PIK-tus) - Painted. The appearance of being painted.
PILEATUS, -a, -um (pil-ee-AY-tus) - Furnished with a cap.
PILOSE (PYE-lose) - With long, soft hairs.
PILOSUS, -a, -um (pye-LOH-sus) - Covered with long soft hairs; pilose.
PINNATE (PIN-ate) - With leaf arrangement on both sides of a rachis in featherlike fashion.
PINNATUS, -a, -um (pin-NAY-tus) - Featherlike, having leaflets arranged on each side of a common stalk; pinnate.
PISIFORM (PYE-sih-form) - Pea shaped
PISTIL (PIS-til) - The seed bearing organ of the flower, consisting of the ovary, stigma and style, when present.
PISTILLATE (PIS-ti-late) - Of a flower with fertile parts represented by carpels only. The ovule-bearing organ of a seed plant. Having pistils and no stamens; female.
PITTED - Marked with small depressions or pits.
PLACATUS, -a, -um (pla-KAY-tus) - Quiet; calm; placid.
PLACENTA (pla-SEN-ta) - That part or place in the ovary where ovules are attached.
PLAITED (PLA-ted) - Folded lengthwise, as a closed fan; pleated; plicate.
PLANUS, -a,-um (PLAY-nus) - Flat; plane.
PLAQUE (plack) - A vertical growing substrate of cork, tree fern, wood or other material. (See slab)
PLASTID (PLAS-tid) - A class of cellular organelles that contains either pigments (chloroplast, chromoplast) or starch (amyloplast).
PLATY- (PLAT-ee) - In Greek combinations, signifying "broad," "wide" or "flat."
PLENUS, -a, -um (PLEE-nus) - Double or full.
PLESIOMORPHY (PLEE-zee-oh-more-fee) - A cladistic term referring to an ancestral character state.
PLICATE (PLY-kate) - Folded like a fan.
PLICATILIS, -e (ply-ka-TYE-lis) or (plye-kayt-EYE-liss - Folded; plicate.
PLICATUS, -a, -um (plye-KAY-tus) - Folded like a fan, or pleated; plicate.
PLOIDY (PLOY-dee) - The number of sets of chromosomes in a cell.
PLUMOSUS, -a, -um (ploo-MOH-sus) - Feathery; featherlike; plumose.
POD - Horticultural (but botanically incorrect) term for the seed capsule of an orchid. A dehiscent fruit containing the seed.
POLLEN (POL-len) - The fertilizing grains contained in the anther.
POLLINARIUM (pol-li-NAIR-ee-um) - The inclusive term for the pollination unit of most orchids, comprising pollinia and caudicles, viscidium, or viscidium and stipe.
POLLINATION (pol-i-NAY-shun) - The act of transferring pollen from an anther to a stigma.
POLLINATION BIOLOGY (pol-li-NAY-shun bye-ol-OH-gee) - The study of the interaction between floral morphology and pollinator behavior.
POLLINIA (sing. pollinium) - (pol-LIN-ee-a) - The masses of waxy pollen or of coherent pollen grains found in the anthers of most orchids.
POLLINIFEROUS (pol-li-ni-FER-us) - Having pollen.
POLY- (POL-ee) - In Greek combinations, a prefix signifying "numerous" or "many."
POLYANTHUS, -a, -um (pol-ee-AN-thus) - Many-flowered.
POLYBULBON (pol-i-BUL-bon) or (pol-ee-BUL-bon) - Having many bulbs.
POLYEMBRYONY (pol-ee-em-BREE-on-nee) - Having more than one embryo in an ovule.
POLYETHYLENE (pol-ee-ETH-i-leen) - A nearly transparent plastic which, in sheet form, is used as a temporary greenhouse covering or as inside insulation.
POLYGAMOUS (pol-IG-a-mis) or (pol-IG-ah-mus) - Bearing both hermaphrodite and unisexual flowers on the same plant or on different plants of the same species..
POLYGAMUS (See POLYGAMOUS).
POLYMIN (POL-i-min) - A term applied to hybrids between polypoid and miniature Cymbidiums.
POLYMORPHIC (POL-i-MOR-fik) or (pol-ee-MOR-fik) - Having or assuming various forms, character, or styles.
POLYMORPHISM (POL-i-MORE-fiz'm) - Differentiation within a population of a particular habitat as a phase of the process of selection.
POLYPHYLETIC (pol-ee-FIH-let-ik) - An artificial taxon in classification that has two or more ancestral groups.
POLYPLOID (POL-i-ployd) or (POL-ee-ployd) - Having several sets of chromosomes. Having more than 2 sets of matching chromosomes, such as triploids (3 sets), tetraploids (4 sets), and hexaploids (6 sets).
POPULATION (pop-yu-LAY-shun) - The assemblage of progeny from a single mating or from a series of similar matings, particularly in the wild.
PORECT (po-RECKT) - Directed outward and forward; not stretched out.
POROSUS, -a, -um (por-OH-sus) - With small holes, pores or perforations; porose.
PORRECT (por-REKT) - Directed outward and forward.
POSTERIOR - Next or toward the main axis; the reverse of anterior.
POSTULAR (poss-tewl-ar) - Having blisterlike projections
POT - (1) A container, usually cylindrical and tapered, made of baked clay, plastic or other material, in which orchid plants are grown; (2) to plant an orchid in such a container.
POTSHARD (POT-shard) - A piece or fragment of a broken earthen pot.
POTTING - The act of placing an orchid plant in a container and securing it in a medium for support and growth.
PRAECOX (PREE-cox) - Early blooming; very early; precocious.
PRAEMORSE (PREE-mors) - Jagged as if bitten off.
PRAEMORSUS, -a, -um (pree-MOR-sus) - Jagged, as if bitten off at the end.
PRAESTANS (PREE-stanz) - Standing in front; excelling; distinguished.
PRASINUS, -a, -um (pray-SYE-nus) - Grass-green.
PRECOCIOUS (pre-KOE-shus) - Developing very early.
PRICKLE (PRIH-kl) - A sharp outgrowth from the epidermis
PRIMARY - The first part to develop.
PRIMORDIUM (pri-MOR-di-um) - Site of active cell division initiating new growth of parts. The rudiment or commencement of any part or organ. The first recognizable histologically undifferentiated stage in the development of an organ
PRIMULINUS, -a, -um (prim-yew-LYE-nus) - Resembling a primrose.
PRINCEPS (PRIN-seps) - Distinguished.
PRISMATOCARPUS, -a, -um (priz-mat-oh-KAR-pus) - Having prism-shaped seed pods with three flat sides and three sharp angles.
PROBOSCIDEUS, -a, -um (proh-bos-SID-ee-us) - Snout-like.
PROBOSCIS (proh-BAW-siss) - The elongate feeding organ of an insect, formed of the mouth parts.
PROCESS - An extension of any surface or part beyond the main outline.
PROCUMBENS (pro-KUM-benz) - Prostrate; lying flat along the ground.
PROCUMBENT (proh-KUM-bent) - Trailing or lying flat, but not rooting.
PRODUCTUS, -a,-um (proh-DUK-tus) - Lengthened; extended or prolonged; produced.
PROFUSUS, -a, -um (proh-FEW-sus) - Abundant; profuse.
PROLATUM (pro-LAY-tum) - a prolate spheroid. (See Ellipsoid)
PROLIFERATION (pro-lif-er-AY-shun) or (pro-lih-fer-AY-shun) - Producing offshoots; growing by multiple division.
PROPHYLLUM (pro-FILL-um) - The small bract at the base of a flower.
PROSTRATE (PROS-trate) - Lying flat on the ground.
PROTOCORM (PRO-toe-corm) - The first grown, a tuber-like body produced by a germinating orchid seed prior to the production of leaves, roots, etc.
PROTOLOGUE (PRO-toh-log) - The information presented at the place and time of publication of a new taxon.
PROXIMAL (PROK-sim-al) - The part nearest the axis.
PRUINOSUS, -a,-um (prew-in-OH-sus) - Covered with a whitish, frostlike bloom; excessively glaucous; pruinose.
PSEUDO- (SOO-doh) - A Greek prefix meaning false.
PSEUDOBULB (SOO-do-bulb) - The solid bulbous enlargement of the stem found in many orchids. The pseudobulb functions as a water and food storage device. It does not contain concentrically arranged leaves modified for food storage. A thickened portion of a stem, resembling a bulb but not being a true bulb, which is a modified stem composed of bulb scales.
PSEUDOBULBLESS (SOO-doh-BULB-less) - The condition of not having a noticeable pseudobulb.
PSEUDOBULBOUS (SOO-do-bul-bus) - Having pseudobulbs.
PSEUDOCOPULATION (SOO-doh-kop-yu-LAY-shun) - A form of pollination in orchids wherein the flower mimics a female insect fooling the male enough to cause him to pollinate the flower.
PSYCODES (sye-KOH-deez) - Fragrant.
PTEROCARPUS, -a, -um (tare-oh-KAR-pus) - Having a winged fruit.
PUBERULENT (poo-BER-yew-lent) or (pew-BEH-ru-lent) - Minutely downy. Finely pubescent.
PUBESCENS (pew-BESS-enz) - Downy; covered with fine short hair; pubescent.
PUBESCENT (pew-BES-end) - An epidermal covering of soft hair.
PUDICUS, -a, -um (PEW-dik-us) - Modest; bashful.
PUGIONIFORMIS, -e (pew-ji-on-i-FORM-is) - Dagger shaped.
PULCHELLUS, -a, -um (pul-KEL-lus) - Fair, pretty.
PULCHER, pulchra, pulchrum (PUL-ker) - Beautiful, lovely.
PULLUS, -a, -um (PULL-us) - Dark colored.
PULVINATUS, -a,-um (pull-vin-AY-tus) - Formed like or resembling a cushion.
PUMILUS, -a, -um (PEW-mill-us) - Dwarf, or low-growing.
PUNCTATE (PUNK-tate) - Dotted with translucent glands or spots.
PUNCTATUS, -a, -um (punk-TAY-tus) - Spotted; marked with dots, depressions or translucent glands; punctate..
PUNGENT (pun-jent) - Acid to the taste.
PURPURASCENS (per-per-ASS-enz) - Becoming or turning purple; purplish.
PURPURATUS, -a, -um (per-per-AY-tus) - Marked with purple so as to have a certain regal quality.
PURPUREUS, -a, -um (per-PER-ee-us) - Purple.
PURUS, -a, -um (PUR-us) - Spotless; of one color.
PUSILLUS, -a, -um (pew-SILL-us) - Very small.
PYGMAEUS, -a, -um (pig-MEE-us) - Very small; pygmy.
PYRAMIDAL (pi-RAM-i-dal) - Pyramid-shaped.
PYRAMIDALIS, -e (peer-a-mid-DAY-liss) - Pyramid shaped; pyramidal.
PYRIFORM (PIR-i-form) - Having the form of a pear. Pear-shaped.
PYRIFORMIS, -e (peer-i-FOR-miss) - Pear shaped; pyriform.
PYXIDATE (piks-UH-dayt) - Having a lid.

Q
QUADRATE (KWAD-rate) - Four-sided.
QUADRATUS, -a, -um (kwad-RAY-tus) - Four-sided; quadrate.
QUADRICOLOR (KWAD-ri-ko-lor) - Four-colored.
QUADRICORNIS, -e (KWAD-ri-korn-is) or (kwad-ri-KOR-niss) - Four-horned.
QUADRIGENERIC (KWAD-ri-jen-er-ik) or (kwad-ri-jen-AIR-ik) - Pertaining to four genera, primarily used to describe hybrids which contain genetic material from four different genera.
QUAQUAVERSAL (KWA-kwa-VER-sal) – Turning, twisting or dipping in any or every direction.
QUATERNATUS, -a, -um (kwa-ter-NAY-tus) - In fours; quaternate.
QUINATUS, -a, -um (kwin-AY-tus) - In fives.
QUINQUENERVIS, -e (kwin-kwe-NER-viss) - Having five nerves or veins.
QUINQUEPARTITUS, -a, -um (kwin-kwe-par-TYE-tus) - Being five-parted.
QUINQUEVULNERUS, -a, -um (kwin-kwe-vul-NER-us) - Having five wounds, or blood-red spots.

R
RACE (reys) - A group of individuals within a species, all of which possess one or more distinguishing characteristics.
RACEME (ray-seem) - usually an elongate, unbranched, cluster of flowers along the main stem. A simple inflorescence of stalked flowers on a common, more or less elongated axis.
RACEMIFORM (ray-see-ma-form) - an inflorescence that appears to be a raceme.
RACEMOSE (ra-se-mos) - having stalked flowers along an elongated stem that continue to open in succession from below as the stem continues to grow; an inflorescence that has flowers that are set in a zigzag from side to side.
RACEMOSUS, -a, -um (ras-see-MOH-sus) - With flowers borne in racemes, resembling a raceme; racemose.
RACHIS (ray-kiss) - the central spine or axis of an inflorescence.
RADIANS (RAY-di-anz) - Radiating outward.
RADIANT (Ray-dee-nt) - Coming from a central point.
RADIATE (ray-dee-ate) - spreading outward from a common center.
RADIATUS, -a, -um (ray-dee-AY-tus) - Spreading out from a common center; with rays; radiate.
RADICAL (rad-e-cul) - arising from the root or near the nexus of the stem and root.
RADICANS (RAD-ik-anz) - Having rooting stems.
RADICLE (RAD-i-kul) - The embryonic plant root.
RADIX (RAY-diks) - A root.
RAFT - a wood or tree fern plaque that is used to attach an orchid for it to root to. A large, flat basket made of interlocking pieces of wood.
RAMEAL (RAY-mee-al) - Belong to a branch.
RAMET (ray-met) - an individual of a clonal line.
RAMICAUL (ram-e-call) - well developed erect one leafed stems ie. Zootrophion, pleurothallis. A morphologic term for the so-called "secondary stem" of the Pleurothallidinae.
RAMIFACTION (rahm-ih-FIH-kay-shun) - Branching.
RAMOSUS, -a, -um (ram-OH-sus) - Branched; ramose.
RAMULOSE (RAM-yuh-lohs) - Having many branches.
RANIFERUS, -a, -um (ran-NI-fer-us) - With a frog-like callus .
RANKS (rangks) - Rows, as in the arrangement of flowers in an inflorescence.
RAPHE (RAYF-a) - A ridge.
RAPHIDES (RAYF-ids) - Needlelike crystals, usually of calcium oxalate, which occur in the cells of many plants.
RARUS, -a, -um (RARE-us) - Rare; uncommon.
RAUCUS, -a, -um (RAW-kus) - Hoarse; raw; raucous.
RECEPTACLE - The summit of the flower stalk bearing the floral organs.
RECESSIVE (ree-SESS-iv) - Said of an allele that is not expressed when paired with a dominant allele; also, the phenotypic character thereof.
RECIPROCAL CROSS (ree-SIP-ro-cul kraws) - A repeat of a cross in which the original roles of the pollen and seed parents are reversed.
RECLINATE (rek-li-nate) - turned or bent down from the apex.
RECLINATUS, -a, -um (rek-lin-AY-tus) - Bent backward; reclining; reclinate.
RECLINING - leaning backward from the vertical.
RECOMPLICATE (rek-om-pli-cate) - folded back on itself and then folded again.
RECONDITE (REK-on-dyet) - Concealed; difficult to make out; not easily recognized.
RECTUS, -a, -um (REK-tus) - Upright; erect.
RECURVED (re-curved) - curved or curled downwards or backwards.
RECURVUS, -a, -um (ree-KER-vus) - Bent backward, recurved.
REFLASKING (ree-flask-ing) - Transplanting small seedlings from one flask into a flask of fresh medium to permit greater growth before deflasking the seedlings into community pots or thumb pots.
REFLEXED (re-flex-t) - suddenly bent backwards.
REFLEXUS, -a, -um (ree-FLEK-sus) - Abruptly bent backward or downward; reflexed.
REFULGENS (ree-FUL-jenz) - Shining brightly.
REGALIS, -e (ree-GAY-liss) - Of outstanding merit; regal.
REGINAE (re-JYE-nee) - Of the queen; queenly.
REGISTRANT (rej-ih-STRANT) - The person or firm in whose name an application is made for the registration of an orchid hybrid.
REGISTRAR (rej-ih-STRAR) - The official of the Royal Horticultural Society (London) - International Registration Authority responsible for the processing of applications to register orchid hybrids.
REGISTRATION - The process and procedures for the recording of the name and parentage of a new orchid hybrid under the jurisdiction of the International Registration Authority.
REGIUS, -a,-um (REE-jee-us) - Royal; regal.
REGULAR - Uniform or symmetrical in shape or structure.
REGULATOR GENE (reg-yuh-LAY-tore jeen) - Any gene that controls the expression of another gene.
REMONTANT  (ri-mon-tent) - blooming more than once in a season.
REMOTE - distant.
REMOTUS, -a, -um (ree-MOH-tus) - Scattered; not close together; remote.
RENIFORM (ren-i-form) - kidney shaped.
REPANDENS (ree-PAN-denz) - With a gently wavy or fluted margin; undulate; repand.
REPENS (REE-penz) - Creeping; prostrate and rooting at the nodes; repent.
REPENT - ground creeping and rooting at the joints.
REPLICATUS, -a, -um (rep-li-KAY-tus) - Doubled back; folded; replicate.
RESINIFEROUS (RES-in-if-er-us) - Resin producing.
RESPIRATION (res-per-AY-shun) - The processes used by organisms to produce metabolically usable energy from oxidative breakdown of food.
RESUPINATE (re-soo-pin-ate) - the flower is reversed by a 180' twist of the pedicel during development and holds the lip at the bottom and the dorsal sepal above. With the lip on the lower side of the flower in respect to the rachis; used to refer to flowers with the lip lowermost regardless of orientation. Most orchids are resupinate.
RETICULATE (re-tik-yew-lat) - net like.
RETICULATIONS (re-tik-yew-lay-shuns) - a network of veins or lines on a leaf surface.
RETICULATUS, -a, -um (re-tik-yew-LAY-tus) - In the form of a network; reticulate.
RETICULUM (re-TIK-yuh-lum) - A network of fibers.
RETINACULUM (re-ti-nak-yew-lum) or (ret-in-AK-yuh-lum) - the attachment of stipitate pollina to the rostellum. In Orchidaceae, the gland where one or more pollinia are attached.
RETRACTED (re-trak-ted) - drawn back.
RETROFLEX (re-tro-fleks) - bent or turned backwards.
RETRORSE (retrorse) or (re-TRORSS) - turned, bent or curved away from the apex. Directed back or downward.
RETUSE (re-toos) - having the end rounded and slightly indented; as, a retuse leaf.
RETUSUS, -a, -um (re-TEW-sus) - Rounded at the end, but with a broad and shallow notch in the center; retuse.
REVERSED - in a flower, not having a twisted pedicel, non resupinate.
REVERSION (ree-VER-zhuhn) - A change backward to an earlier condition.
REVERSUS, -a, -um (ree-VER-sus) - Turned around; reversed.
REVOLUTE (rev-o-lute) - rolled backward from the tip or margins to the undersurface.
REVOLUTUS, -a,-um (rev-oh-LEW-tus) - Rolled backward from the margin or apex; revolute.
RHACHIS (RAY-kiss) - See rachis.
RHIZOMATOSE (RYE-zoh-mah-tose) - Having the characteristics of a rhizome.
RHIZOMATOUS (rye-zo-ma-tus) - having rhizomes as its form of food storage or mode of spreading.
RHIZOME (rye-zome) - a stem that runs horizontally along, above or below the soil surface, putting out roots along its length and sending up shoots or pseudobulbs at intervals.
RHIZOME CLIP (RYE-zohm klip) - A bent piece of heavy wire that fastens to the side of a pot, used to stabilize a newly potted orchid that bears a rhizome.
RHOMBIC (rom-bik) - of the lamina, nearly square with petiole at one of the acute angles. Top-shaped; an equilateral figure having oblique angles.
RHOMBOID (ROM-boyd) - Having the shape of a rhombus, i.e., a parallelogram with oblique angles and equal sides.
RHS (Royal Horticultural Society) - Horticultural society based in London; responsible for registering orchid hybrids.
RIB - a distinct vein or linear marking, often raised as a linear ridge. In a leaf or similar organ, the primary vein; also any prominent vein or nerve.
RIBBED - possessing raised veins or nerves.
RIBONUCLEIC ACID (RNA)  (RYE-bow-new-CLAY-ik as-id) - Nucleic acid formed on a DNA template and involved in directing protein synthesis within the cell.
RIGIDUS, -a, -um (RIJ-id-us) - Stiff; unbending; rigid.
RIMOSUS, -a, -um (ri-MOH-sus) - With cracks or chinks; cracked; fissured; rimose.
RINGENS (RIN-jenz) - Gaping; said of labiate flowers with an open throat or mouth.
RINGENT (rin-jint) - wide open and gaping.
RIPARIAN (RYE-pare-ee-en) - Said of plants growing near a stream or river.
RIVALIS, -e (ri-VAY-liss) - Growing along streams.
ROLLER SHADES (ROH-ler sheyds) - A curtain, made of slats, evenly spaced, or other shade material that can by means of ropes or cords be rolled and unrolled over the outside or inside of a greenhouse roof (and sometimes sides) - to regulate the amount of sunlight admitted.
ROOT - The underground portion of a plant. It supports the plant and supplies water and nutrients to the upper portion
ROOTSTOCK - (See rhizome)
RORIDULOUS (ror-e-due-lus) - covered with small transluscent projections giving the appearance of being dew covered.
ROSELLATE (ro-sell-it) - held in a rosette or radiating cluster of leaves.
ROSETTE (rose-ette) or (roh-ZET) - A radiating or circular cluster of leaves or other organs.a cluster of leaves growing in crowded circles from a common center or crown.
ROSEUS, -a, -um (ROH-zee-us) - Rose-colored; delicate pink; rosy.
ROSTELLUM (ros-tell-lum) or (ros-TELL-um) - a structure on the column as a little beak. A slender extension from the upper edge of the stigma. A sometimes beaklike extension of the stigma, a gland that produces a viscous substance used in pollination. Also separates the female portion from the male portion of the flower, preventing self-pollination.
ROSTRATE (ros-trate) - beaked, the apex narrowed into a slender, usually obtuse point
ROSTRATUS, -a, -um (ros-TRAY-tus) - Having a projection like the beak of a bird; beaked; rostrate.
ROSTRUM (ros-trum) - a beak like extension.
ROSULA (ross-YUH-la) - A rosette.
ROSULATE (ross-YUH-layt) - In the form of a rosette.
ROTATUS, -a, -um (roh-TAY-tus) - Wheel-shaped; rotate.
ROTUND (row-tund) - rounded or curved as in an arc.
ROTUNDATUS, -a, -um (roh-tund-AY-tus) - Nearly circular; rounded; rotund.
ROTUNDIFOLIUS, -a, -um (roh-tun-di-FOH-li-us) - With round or rounded leaves.
RUBELLUS, -a, -um (roo-BEL-lus) - Reddish-colored.
RUBER, RUBRA, RUBRUM (ROO-ber) - Red. In compound words, rubri- or rubro-
RUBESCENS (roo-BESS-enz) - Rosy red, or suffused with rose; blushing; reddish-colored.
RUBIGINOSUS, -a, -um (roo-bij-in-OH-sus) - Rusty; rust-colored; rubiginous.
RUBRO-OCULATUS, a, -um (roo-broh-ok-yew-LAY-tus) - Red-eyed.
RUBRO-PURPUREUS, -a, -um (roo-broh-purr-PURR-ee-us) - Reddish purple.
RUDERAL (ROO-der-uhl) - Growing in waste spaces.
RUDIMENTARY (rhu-da-men-ta-ree) or (roo-dih-MEN-tah-ree) - imperfectly developed. being in the earliest stages of development. Arrested in an early stage of development.
RUFESCENS (roo-FESS-enz) - Reddish brown.
RUFESCENT (ru-fes-sent)  - reddish brown. tinged with red.
RUFOUS (roo-fus) - reddish brown.
RUGOSE (roo-gose) - uneven texture. deeply wrinkled.
RUGOSUS, -a, -um (roo-GOH-sus) - Roughened by wrinkles; rugose.
RUGULOSE (roo-gue-lose) - finely wrinkled. a diminutive of rugose
RUGULOSUS, -a, -um (roo-gew-LOW-sus) - Minutely rugose; finely wrinkled; rugulose.
RUMINATE (roo-mi-nate )- seemingly chewed on. Appearing as having been chewed.
RUNCINATE (run-sin-ate) - having sharp teeth facing backwards. Sharply incised, the segments bent backward.
RUNNER (RUH-ner) - A slender trailing shoot taking root at the nodes.
RUPESTRIS, -e (roo-PESS-triss) - Growing in rocky places; rock-loving.
RUPICOLUS, -a, -um (roo-PIK-oh-lus) or (Rah-pik-o-lus) - Growing in cliffs and ledges; growing on or among rocks rupicolous.
RUST (ruhst) - A fungal disease.
Definitions A-F Definitions G-L Definitions S-Z Color Definitions