Definitions

abaxially - facing away from the axis of an organ or organism "the abaxial surface of a leaf is the underside or side facing away from the stem"

acaulescent - having no apparent stem above ground

acuminate - [adj]  of a leaf shape; narrowing to a slender point

acute - terminating in a distinct but not protracted point, the converging edges separated by an angle less than 90°.

adaxial - nearest to or facing toward the axis of an organ or organism; "the upper side of a leaf is known as the adaxial surface"

adnate - Growing together; -- said only of organic cohesion of unlike parts.

adventitious - arising at various points along a stem, rather than at the base or apex, or another such specific zone.

aerial root -  Any root produced above the growing medium.

aggregated - formed of separate units in a cluster. Raspberries are aggregate fruits

alternate - (of the arrangement of leaves) arising one from each node in a staggered formation.

anther - the pollen producing part of the stamen. The other part is the filament (stalk).

apex - the highest point

apical - At or belonging to an apex, tip, or summit.

articulate - Jointed; having joints where separation may occur naturally; of a stem, having nodes.

ascending - arising at a steep angle, but not vertical.

attenuate - Tapering gradually.

axil - The upper angle formed by a leaf or branch as it grows from the main axis (main stem). The angle between a leaf or bract and the axis bearing it.

axillary - Situated in, or rising from, an axil; of or pertaining to an axil. Adj.: Angle between a branch or leaf and the stem it grows from.

backbulb - An old pseudobulb behind the part of a sympodial orchid that is actively growing. Although there may be no leaves the presence of undamaged "eyes" is a sign that growth is possible.

basal - At the base of a structure.

bifoliate - having two leaves

bigeneric - A hybrid between two species of different genera.

blush, or flush - Refers to a different color overlay of the base color of a flower., i.e. a red blush

botrytis - a microscopic fungus that causes rot in flowers and fruits.

bract - Modified leaves on an inflorescence,

caespitose - growing in dense clumps or tufts

callus  - an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid

calyx - (plural calyces) the lowest or outermost of layers attached to the receptacle of a flower. The calyx consists of sepals that may be separate or partly or fully fused to one another and which are commonly green in contrast to the more colorful petals.

cane - An elongated psuedobulb, usually used when describing Dendrobiums or Epidendrums.

capitate - being abruptly enlarged and globose at the tip. Of an inflorescence, with the flowers unstalked and aggregated into a dense cluster; of a stigma, globose, like the head of a pin.

carpel - the fundamental unit of a flowers gynoecium (female organ) usually differentiated into an ovary containing ovules (embryonic seeds) and a narrower style tipped by a stigma which receives pollen. Carpels may be single or multiple, and multiple carpels are often fused together.

cauline - growing on a stem especially on the upper part of a stem

clavate - Club-shaped; having the form of a club; growing gradually thicker toward the top.

cleistogamous - having small inconspicious flowers that are pollenated from their own anthers.

clone - Vegetative propagation from an individual plant.

column - (in orchids) the fleshy structure in the flower's center consisting of a fused style, stigma, and stamens. Similar structures are found in other plants.

column foot - The extension of the base of the column, in some orchids, to which the lip is attached.

conduplicate - Folded together, with the fold-line along the long axis

coriaceous - resembling or made to resemble leather; tough but pliable

corolla - The inner of the two series of floral segments, which are the sepals and petals.

crock - Small pieces of broken clay flower pots, or other materials, placed in the bottom of a pot to aid in drainage.

cultivar - An cultivated plant and its vegetative propagations; a horticultural variety or strain.

deciduous - shedding foliage at the end of the growing season

decussate - arrangement of opposite leaves in which each leaf pair is oriented at right angles to the next pair below it. This creates four vertical ranks of leaves.

dehiscent - (of e.g. fruits and anthers) opening spontaneously at maturity to release seeds

digitate - Branches clustering from one point like fingers on a hand.

dioecious - male and female flowers borne on different plants. Plants of both sexes must be present for pollination to occur. Flowers can be termed dioecious if of different sexes and borne on the same plant.

diploid - having 2 matched sets of chromosomes.

discolor - Having two-toned leaves, such as green above and purple below.

distal edge - Remote from the point of attachment or origin; as, the distal end of a bone or muscle; -- opposed to {proximal}.

distichous - Arranged in two rows on opposite sides of a stem and thus in the same plane

diurnal - opening flowers during the daytime. See noctural.

divaricate - spread apart, branch off

dorsal - the side of a plant organ that, when it is expanding from the bud, faces away from the axis to which it is attached. In a normal leaf, the dorsal side is the underside. In an orchid flower, the apparent upper sepal is called the dorsal sepal.

ellipsoid - a spheroid; a solid figure generated by the revolution of an ellipse about one of its   axes. It is called a prolate spheroid, or prolatum, when   the ellipse is revolved about the major axis, and an oblate spheroid, or oblatum, when it is revolved about the minor axis.

emarginate - having a notched tip, or slightly indentedurface.

endemic - occurring in the wild in only one readily defined region.

ensiform - shaped like a sword blade; "the iris has an ensiform leaf"

epiphyte, epiphytic - An air plant; A plant which grows upon another plant, for support, but does not derive any nourishment from the host plant. Many of the orchids in cultivation are epiphytic in their natural habitats.

equitant - Overlapping each other; -- said of leaves whose   bases are folded so as to overlap and bestride the leaves   within or above them, as in the iris.

exotic - a plant that is NOT native to the region. Not endemic.

exserted - Protruding, e.g. of stamens with respect to a corolla tube

eye - The bud of a sympodial (many footed) orchid that will eventually develop into a new psuedobulb and flower.

fascicled - Growing in a bundle, tuft, or close cluster; as, the fascicled leaves of the pine or larch; the fascicled roots of the dahlia; fascicled muscle fibers; fascicled tufts of hair.

fasciculate - Clustering habit. Offsets from the base form tight bunches.

filament - the stalk of a stamen, bearing the anther anther at its tip.

filiform - Thread-like.

floccose - Wooly or fuzzy.

flush - see blush above.

foliar spray - Many minor nutrients and trace elements beneficial to growth are best absorbed through the stomata of an orchids leaves when mixed with water and sprayed on the plant.

formula - In regards to hybrids, the parents' name forming the hybrid. The names are connected by the multiplication sign X (by)

fusiform - Spindle-shaped, i.e. narrower at both ends than at the center.

genus - (pl. genera) A natural grouping of closely related species.

glabrous - having no hair or similar growth; smooth

glaucous - A sea-green color, coated with a waxy powder.

globose - Rounded or spherical shape.

grex - All siblings of the same seed cross.

habitat - The type of place, or environment, in which a Orchid normally grows.

herbarium sheet - A paper with a prepared and dried plant specimen used for identification.

hyaline - Translucent, almost like clear glass.

hybrid - The result of a cross between two different species or hybrids.

hybrid swarm - A cross between two species that becomes fertile and breeds true, imitating a true species.

imbricated - overlapping or layered as scales or shingles

indigenous - forming part of the original natural flora of a region (but not necessarily endemic)

Inflorescence - The group or arrangement in which flowers are borne on a plant.

intergeneric hybrid - A hybrid between members of two or more genera.

jointed - having nodes, or points of real or apparent divisions along the stem or psuedobulb.

keeled - Of leaves or bracts, folded and ridged along the midrib.

keiki - A Hawaiian word referring to a baby plant produced asexually by an orchid plant, usually randomly along a section of the pseudobulb. Used when referring to Dendrobiums, Phalaenopsis, or Vandaceous orchids.

labellum - (in orchids) the usually large and distinctive pedal that commonly juts forward from the flowers center.

lamina - "The blade of a leaf; the broad, expanded portion of a petal or sepal of a flower."

lanceolate - Lancelike; of a leaf, about four times as long as it is broad, broadest in the lower half and tapering towards the tip.

lateral - situated at or extending to the side; "the lateral branches of a tree"; "shot out sidelong boughs"

lead - An immature vegetative growth on a sympodial orchid that will develop into flower-producing structure.

ligulate - strap-shaped

linear - Very narrow in relation to the length, and with the sides parallel

lip - an upper or lower lobe, or group of lobes, of the usually tubular corolla. Most flowers with lips have 2 lips.

lip - A modified petal of the orchid flower specialized to aid in pollination and different than the other petals. Most flowers with lips have 2 lips.

lithophyte - An orchid that grows on rocks

medium - The material in which an orchid is container-grown, it may be organic such as fir bark or inorganic such as lava rock.

mericlone - A plant derived from tissue culture that is identical to its parent.

meristem - The actively growing tissue of a plant, used for artificial cloning.

mesic - Constantly moist.

monopodial - Orchids which grow upward from a single stem producing leaves and flowers along that stem.

mycorrhiza - 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.

node - A joint on a stem or pseudobulb from which a leaf or growth originates.

oblanceolate - Shaped like a lance, point reversed, that is, having the tapering point next to the leafstalk.

oblique - 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 parallel.

obtuse - Blunt or rounded at the apex, the converging edges separated by an angle greater than 90 degrees.

obvate (obovate) - of a leaf shape; egg-shaped with the narrower end at the base

offset - A vegetative division or lateral shoot. Synonym: keikei.

opposite - attached to the stem in pairs, on opposite sides of the node.

ovary - the swollen part of a female organ containing the ovules

ovate - Shaped like an egg in two dimensions, and attached by the wider end.

ovoid - Egg-shaped (in three dimensions). 

ovule - the egg, which after fertilization, becomes the seed.

pachycaul - An abnormally thick-stemmed plant.

pandurate - Obovate, with a concavity in each side, like the body of a violin; fiddle-shaped; as, a panduriform leaf; panduriform color markings of an animal.

panicle - 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.

paniculate - Indeterminate and much branched.

papilla - A small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.

papillose - Covered with, or bearing, papill[ae]

pedicel - a small stalk bearing a single flower of an inflorescence; an ultimate division of a common peduncle

pedicellate - Having a pedicel; supported by a pedicel.

peduncle - The stem or stalk that supports the flower or fruit of a plant, or a cluster of flowers or fruits

pendent -  supported from above; "fuchsias in hanging pots"; "pendent bunches of grapes"; dangling, hanging, suspended

perianth - the parts of a flower that enclose the sexual organs in the bud, normally the corolla (the combined petals) and the calyx (the sepals).

petal - One of the segments of the corolla of a flower. In Orchids, one of the three petals is usually modified into a lip or labellum.

petiolate - Having a stalk or petiole; as, a petiolate leaf;

petiole - The stalk portion of a leaf.

photosynthesis - 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.

pistillate - having gynoecia, or pistils, the ovule-bearing organ of a seed plant

plicate - Folded back and forth longitudinally like a fan.

polyploid - Having more than 2 sets of matching chromosomes, such as triploids (3 sets), tetraploids (4 sets), and hexaploids (6 sets).

pseudobulb - A thickened portion of the stem, resembling a bulb, of many orchids, and some bromeliads. The pseudobulb functions as a water and food storage device. It does not contain concentrically arranged leaves modified for food storage.

pyriform - Pear-shaped.

quadrigeneric - Pertaining to four genera, primarily used to describe hybrids which contain genetic material from four different genera.

raceme - usually an elongate, unbranched, cluster of flowers along the main stem in which the flowers at the base open first

racemose - having stalked flowers along an elongated stem that continue to open in succession from below as the stem continues to grow;

rachis - The central spine of an inflorescence.

recurved - Curved or curled downwards or backwards.

reticulations - A network of veins or lines on a leaf surface.

retuse - Having the end rounded and slightly indented; as, a retuse leaf.

rhizomatous - having rhizomes as its form of food storage or mode of spreading.

rhizome - a stem that runs horizontally along, above or below the soil surface, putting out roots along its length and sending up shoots or psuedobulbs at intervals.

rosette - a cluster of leaves growing in crowded circles from a common center or crown

scape - erect leafless flower stalk growing directly from the ground

scapose - having a leafless flower stalk growing directly from the ground;

scarious - Dry and membranous.

semi terete - Applied to the hybrids between terete leaved and strap leaved Vandas.

sepal - The outer segments of an Orchid flower

sessile - refers to a plant part without a stalk (when applied to a stigma, indicates that the style is absent, the stigma being 'sessile' on the ovary).

sheath - A modified leaf that encloses and protects an emerging inflorescence or leaf. Normally dries and sloughs off, when inflorescence or leaf matures.

species - A kind of plant that is distinct from other plants.

speculum - shiny square or U-shaped area found on the lip of some orchids.

spike - An unbranched inflorescence of unstalked flowers. A term sometimes used in place of ‘inflorescence’

squarrose - Consisting of scales widely divaricating; having scales, small leaves, or other bodies, spreading widely from the axis on which they are  crowded; -- said of a calyx or stem.

stamen - the male reproductive organ of a flower. It typically consists of a slender stalk (filament) and a pollen sac (anther).

staminate - capable of fertilizing female organs

stigma - the apical part of the carpel, or of 2 or more fused carpels, that is the receiver of pollen. It is often separated from the ovary by a slender style.

stipe - supporting stalk or stemlike structure especially of a pistil or fern frond or supporting a mushroom cap

stipitate - Supported by a stipe; elevated on a stipe, as the fronds of most ferns, or the pod of certain cruciferous plants.

stolon  - A branch that grows horizontally above the medium and produces roots and shoots at the nodes.

stoloniferous - Having stolons; trailing over the soil surface and rooting at the nodes.

stomata - The breathing pores on the surface of a plant's leaves

striate-nerved - Striped with parallel longitudinal lines or ridges.

style - the slender portion of a carpel, or of several fused carpels, between the stigma and the ovary.

subacute - less than acute

subcapitate - (less than ) being abruptly enlarged and globose at the tip

subglobose - Not quite globose.

suborbicular - Approximately circular.

sulcate - Grooved; furrowed.

sympodial - Of growth, without a single, persistent growing point; changing direction by frequent replacement of the growing apex by a lateral growing point below it; of a stem, growing in the above manner.

sympodial  - Orchids which grow laterally and produce leafy growths along a rhizome

terete - Cylindrical or nearly so; circular in cross-section. Or curled from the edges to form a tapering cylinder.

terminal - At the apex or far end of something.

terrestrial  - Growing on the ground and supported by soil.

tessellated - Having a checkered or mosaic pattern. Broken into small squares or bits, like floor tiles or broken tree bark.

trichome - The scales or hairs which all bromeliads are absorbing organs. These also give plants such as Tillandsias their silvery or fuzzy look.

tridenticulate - having 3 prongs.

triploid - Having an extra set of chromosomes. Often causes gigantism and other genetic morphs.

truncate - cut off more or less squarely.

unifoliate - Having one leaf.

variegated - Having stripes, usually white, usually randomly up each leaf.

velamen - The thick sponge-like covering of the roots of epiphytic orchids which helps prevent water loss and aids in absorption.

verrucose - covered with warts or projections that resemble warts

virus - A type of infectious agent, much smaller than common microorganisms, several forms of which affect certain kinds of orchids.

viscid - having the properties of glue, adhesive, gluey, glutinous, gummy, mucilaginous, pasty, sticky, viscous

visicidium - sticky substance in flowers that allows pollen to attach to or be removed from the pollinating insect.

warm house - A greenhouse, intended for growing Orchids, in which the night temperature is maintained above 60 degrees F.

xeric - Adapted to arid conditions.

xerophyte - plant that is adapted to dry climates and is capable of surviving dry periods other than by seeds or bulbs.

zygomorphic - having only one vertical plane of symmetry (nearly all orchids).