The surface or side of an organ directed away from the axis (usually the lower side).
abaxially - Dealing with the abaxial surface of an organ.
abdomen - The posterior division of an insect's body.
aberrant - Unusual or atypical; differing from the normal form.
abrupt - Changing suddenly rather than gradually.
abscise - To shed or throw off.
abscission - Shedding of plant parts, such as leaves. This may be natural resulting from old age or premature as a result of stress.
achlorophyllous - Having no chlorophyll.
acicular - Needle-shaped.
acranthous - With a
acrodromous - A leaf with two or more veins running in convergent
arches towards the apex.
acrotonic - A
term describing the relationship when the apex of the anther and pollinia are in close
contact with a rostellum or viscidium.
acuminate - Tapering into a long, drawn-out point.
acute - Tapered to a short, sharp point.
adaxial - The surface or side of an organ facing
towards the apex, or next to the axis (usually the upper side).
adnate - Attached by the whole length or a substantial part.
adventitious - Arising in an
unusual position; often said of adventitious roots or buds.
aerial roots - Adventitious
roots arising on stems or pseudobulbs and growing in the air; such roots are
often prominent on monopodial orchids.
aff. - Affinity, a botanical
reference used to denote an undescribed species closely related to or similar to an already
alate - Having
winglike extensions or margins, winged.
allopatric - Growing in different geographical regions.
alternate - Arising at different levels in a straight line or in a spiral.
alternately - Arranged singly at each node, as leaves on different sides of a stem.
amphistomatic - With stomata on both upper and lower surfaces of the leaf.
amplexicaul - Clasping the stem but not entirely encircling it.
anastomoses - A cross-connection of veins in a leaf (network).
anastomosing - Said of venation when it forms a network.
androclinium - Another term for clinandrium.
angular - Ridged along its length, these ridges appearing as angles in the cross-section.
anterior - Front, away from the axis.
anther - The pollen-bearing part of a stamen.
anther cap - The cap-like structure which terminates the column and covers the pollinia.
anthesis - The period of flowering.
anthocyanins - The pigments in plants responsisble for red, blue or purple colouring.
antrorse - Projecting forwards; used for
an arrangement of hairs, the anther or less commonly the
apex - The tip or end.
aphyllus - Lacking leaves.
apical - At the apex.
apiculate - Ending in a short, sharp point.
apomicts - A plant that arises from apomixis.
apomixis - The production of
seeds without the union of sex cells; this is actually a process of vegetative reproduction.
appresed - Lying flat against.
arcuate - Moderately curved, arched.
aristate - Having a stiffish bristle-shaped appendage, awn-like.
articulate - Jointed; with an
asexual propagation - Propagation by vegetative
means; for example, by division, aerial growths or meristem culture.
attenuate - Drawn out.
auricle - An ear-like appendage; sometimes used for a
small outgrowth on the anther of some orchids.
auriculate - Bearing auricles.
autogamy - The
process of self-pollination.
autotrophic - An organism capable of synthesizing its own food from inorganic substances, using light or chemical energy.
axil - Angle formed between adjacent organs in contact;
commonly applied to the angle between a leaf and the stem.
axile - Pertaining to an axis; used to describe ovary placentation when the ovules are attached to a central
axis in the ovary.
axillary - Borne within the axil.
axis - The main stem of a plant or the main part of a plant organ.
backbulb - The older pseudobulbs
which are usually leafless; pseudobulbs often have viable buds and may produce a new shoot when severed from the main part of the plant.
basal - Arising from the base; often said of the point where
an inflorescence arises.
basifixed - Attached by the base, as certain anthers are to their filaments.
basitonic - A term describing the relationship
when the base of the anther or pollinia is in close contact with a viscidium.
beak - A point; often
used for the apical part of the anther (see also rostrum).
bifid - Deeply notched for more than half its length.
bifurcate - Forked or notched.
bigeneric - A term used for hybrids between two genera.
bilobed - Two-lobed.
bilocular - With two cavities or locules.
bisexual - Both male and female sexes present.
blade - The expanded part of a leaf or labellum.
blotch - A large spot of colour of irregular shape.
boss - A term used for the prominent mound on the labellum of Corysanthes species.
botanical - A term used by orchid growers for small-flowered species of limited horticultural interest.
bottom heat - A propagation term used to denote the application of
artificial heat in the basal region of the division or cutting.
bract - A leaf-like structure which lacks a blade or lamina.
bracteate - Bearing bracts.
breakaway - Term used for rocky slopes and hills of different geology to surrounding area.
bristly - With stiff hairs or bristles.
bud - An unopened flower or a new shoot or inflorescence in its early stages of development.
bulbous - Having or resembling a bulb.
bursicle - A membranous sheath which covers the glue in some viscidia.
caducous - Shedding or falling early.
calcarate - Produced into or having a spur.
calcareous - An excess of lime, as in soil.
calceiform - Shaped like a slipper.
calli - Non-secreting glands found on orchid labella; in many
native terrestrial orchids they are important in pollination and associated with deceit or mimicry.
callosities - Raised or mounded
structures (see also calli); also specialised structures on Microtis labella that resemble clusters of sand grains.
callus - A raised, fleshy or plate-like structure found on the labellum; it may have
ridges, bear calli or other outgrowths or be associated
with nectar production.
calyx - All of the sepals of a flower.
campanulate - Shaped like a bell.
campylodromus - The main veins curved and more or less parallel with the leaf margins.
canaliculate - channelled.
cap - A familiar term applied to the anther cap.
capilletium - The sterile hair-like
structures found in the capsules of some epiphytic orchids.
capitulum - A dense head of flowers.
capsule - A dehiscent, dry fruit containing many seeds.
carinate - Keel-shaped.
carpel - Female reproductive organ.
cataphyll - A reduced leaf, eg. bract.
caudate - With long tail-like
appendages or filiform tips; as in the floral segments of Ephippium masdevalliaceum.
caudicle - A term used for a pollinium stalk derived from the anther; an elastic basal extension of
caudiform - Tail-shaped.
cauline - Belonging
to a stem, usually referring to leaves.
cell - The smallest structural unit of an organism that is
capable of independent functioning, consisting of one or more nuclei, cytoplasm, and various organelles, all surrounded by a
semipermeable cell membrane.
cernuous - Nodding or drooping.
chlophyllous - Containing chlorophyll.
chlorophyll - The green
pigment of leaves and other organs; important as a light-absorbing agent in photosynthesis.
chlorotic - A yellowish plant deficient in nitrogen or iron.
ciliate - With a fringe of fine hairs.
cirrhus - A term sometimes used for the filiform appendages on the labellum of Phalaenopsis flowers.
clavate - Club-shaped; thickened towards
the apex; for example, on the sepals of some spider orchids
of the genus Arachnorchis.
claw - Another term for a narrow stalk on the base of a
segment; for example a petal claw in Diuris, labellum claw in Pterostylis.
cleistogamy - The process of self-pollination occurring without the flowers opening.
clinandrium - The apical margins of the column or the cavity where the anther fits.
clonal - Pertaining to a clone, a group of plants propagated vegetatively from one plant.
clone - A group of plants propagated vegetatively from one
plant (usually a superior horticultural form); all members of a clone are genetically identical.
club - A familiar term used for the expanded apical part of sepals or petals; for example Arachnorchis; see also corynosmophore.
clubbed - A term used for thickened segments; see also clavate.
collar - Specialised swollen
area near stem apex in some native deciduous terrestrial orchids.
colluviate - Covered in tiny bumps.
column - The central fleshy structure in orchid flowers
composed of the style and staminal filaments.
column foot - An extension of the base of the column (usually fleshy).
column wings - A
flattened often wing-like appendage of the column which is probably a sterile stamen.
compact - Short, reduced in
length; some epiphytic orchids have variants which have
a compact growth habit.
compressed - Flattened laterally.
concave - Sunken, basin-like; often used in the description of
conduplicate - Folded together along its length, with each half flat.
confluent - Merging together.
congeneric - Belonging to the same genus.
congested - Crowded closely together.
conical - Cone-shaped.
connate - Joined, united; fused at the base or along the
margins; a useful character for identifying some species of Prasophyllum which have connate lateral sepals.
connective - The sterile portion of the anther between the two anther cells.
constricted - Narrowed or drawn together at some point.
contorted - Twisted.
contracted - Narrowed.
convex - Curving outwards.
convolute - Rolled up lengthwise; referring to the way some leaves are folded when young.
co-pollinator - Where more
than one kind of pollinator acts effectively in the pollination of a plant.
cordate - Heart-shaped.
coriaceous - Leathery in texture.
corm - A thick underground stem somposed of several internodes; as in the pseudobulbs of Geodorum terrestre.
costate - Ribbed.
crenate - The margin cut regularly into rounded teeth.
crenulate - The margin cut rugularly into small rounded teeth.
crest - A term used for the callus of some orchids.
crispate - With
the margin curled or crumpled.
crisped - Applied to very wavy or crumpled margins; as in the
labellum margins of many species of Prasophyllum.
cross-fertilisation - Fertilisation by pollen from another flower.
cross-pollination - Transfer of pollen from flower to flower.
cucullate - Having the shape of a cowl or hood; hooded.
cultivar - A horticultural variety of a plant or crop.
cuneate - Narrowest at the base widens evenly upwards and ends as if cut off square, wedge-shaped.
cuniculus - An extra-floral nectary found
on the pedicel or ovary.
cupped - When the segments remain concave and do not become flat.
cupulate - Resembling a small cup; cup-shaped.
cusp - A point or pointed end.
cylindrical - Round in cross-section and not tapered lengthwise.
cymbiform - Shaped like the bow of a boat.
cyme - An inflorescence where
the branches are opposite.
cymose - In the form of a cyne; a branching, determinate inflorescence, with a flower at the end of each branch.
cytology - The branch of biology that deals with the formation, structure, and function of cells.
cytoplasm - The living material within a cell.
damping-off - A condition in which young seedlings are attacked and killed by soil-borne fungi.
deciduous - Falling or shedding of any plant part; used for terrestiral orchids that die back seasonally to a tuberous root system.
decurved - The apex curves downwards but is
not recurved back on itself.
deflexed - Bent abruptly downwards.
dehiscent - Splitting or opening when mature.
deltate - With three sides and broadest below the middle (triangular in flat plane).
deltoid - Triangular in solid form.
dentate - Toothed.
denticulate - Finely toothed.
depauperate - A weak plant or one imperfectly developed.
determinate - Said of a
growth or inflorescence when it has an extension limit.
diandrous - With two anthers.
dichotomous - Forking regularly into two equal branches or parts.
dicotyledon - Any Angiosperm which has two seed leaves and non-parallel venation in the leaves.
diffuse - Widely spreading and much branched; of open growth.
digitiform - Formed like a finger or fingers; finger-shaped.
dimorphic - Existing in two different forms.
dimorphism - The non-flowering plants are strikingly different to the flowering plants.
diploid - With two sets of chromosomes.
disc - The central portion of the labellum where the lobes meet; often the area where the callus is developed.
dissected - Deeply divided into segments.
distal - Away from the base towards
distichous - In two ranks; usually applied to the arrangement of leaves or flowers.
diurnal - During the day, as describing flowers that only open in the day.
dormancy - A physical or physiological condition
that prevents growth or germination even though external factors are favourable.
dormant - The state of a plant when growth has ceased for the year and other activities in the plant have slowed down, usually during winter.
dorsal - The upper or outer surface or edge.
dorsal sepal - The upper-most sepal in nonresupinate orchid flowers.
downcurved - The apex curves downwards but is
not recurved back on itself.
downy - Covered with soft hairs.
dropper - A term used for the short root which bears a
replacement tuber (also known as a sinker).
duplicate - Leaves which are folded once along the centre, the two halves being flat.
ecalcarate - Without a spur.
ecology - The study of the interaction of plants and animals within their natural environment.
eglandular - Hairs that do not have a swollen gland-like structure at the apex; without glands.
ellipsoid - Spindle-shaped in three dimensions, tapering to each end.
elliptic - Oval and flat in a plane, narrowed to each end which is rounded.
elliptical - Oval and flat in a plane, broadest at the middle and tapered to each end.
emarginate - With a shallow notch at the apex.
endemic - Restricted to a particular country, region or area.
endosperm - Tissue rich in nutrients
which surrounds the embryo in most seeds; orchid seeds lack endosperm.
ensiform - Sword-shaped, as in the leaves of Dipodium ensifolium.
entire - Whole; not toothed, lobed or divided in any way.
epedicellate - Without a pedicel.
ephemeral - Short-lived; in flowers referring to those which last a few hours or less.
ephemeral - Short lived or of short duration.
epichile - The apical portion of the labellum.
epidermis - The outermost layer of cells covering the leaves.
epigeous - Growing close to the earth.
epilith - Growing on rocks.
epiphyte - A plant growing on or attached to another plant but not drawing nourishment from it and therefore not parasitic.
epiphytic - Growing on or attached to another plant but not drawing nourishment from it and therefore not parasitic.
epiphytosis - A condition of decline in trees attributed to having too many epiphytes on their trunk and branches.
equitant - Laterally flattened leaves arranged in two ranks that overlap at the base.
erect - Upright.
erose - With an irregular cut or notched margin; as if it has been chewed.
erostrate - Without a beak.
evanescent - Of short duration, passing away quickly.
evergreen - Remaining green and retaining leaves throughout the year.
excrescences - Warty outgrowths that often secrete water;
also used for structures on the labellum margins of Microtis that resemble clusters of cells.
exotic - A plant introduced from overseas.
exserted - Protruding beyond the surrounding parts.
extrafloral - Occurring outside of a flower; as in extrafloral nectaries.
eye - A
horticultural term used for a viable vegetative bud.
falcate - Sickle shaped.
family - A taxonomic group of related genera.
fertile - Mature plant capable
of flowering and producing seed.
fertile bract - A bract which subtends a pedicel (compare with sterile
fertilisation - The act of
union of the male gametes (from the pollen) with the egg cells in the ovules.
fibrose - Containing fibres.
filament - The stalk of the stamen which
supports the anther.
filiform - Very narrow with margins straight and parallel; thread-like.
fimbriate - Fringed, especially along a margin.
flange - Flattened or expanded
extension of a margin.
floriferous - Free-flowering.
foetid - A disagreeable odor.
foliaceous - Leaf-like.
forked - Divided into two equal segments.
four-lobed - In a few orchids that have well developed lateral lobes the midlobe is deeply
divided, the whole structure appearing as if four-lobed.
free - Not joined to any other part except at the base.
fruit - The seed-bearing organ developed after fertilisation.
fugacious - short-lived; in flowers referring to those which last a few hours or less.
furrowed - Grooved longitudinally.
fusiform - Spindle shaped; widest in the middle and tapered to each end.
galea - A hood or helmet-like structure formed
by the fusion of the dorsal sepal and petals; commonly found in the flowers of Pterostylis
and related genera.
gammate - Resembling an upside down capital L; used for calli shape in some genera related to Caladenia.
gamopetalous - With the petals fused.
gamosepalous - With the sepals fused.
genera - A taxonomic category ranking below a family and above a species and
generally consisting of a group of species exhibiting similar characteristics.
genus - A taxonomic group of
closely related species.
geophyte - A plant growing in the ground.
geophytic - A plant growing in the ground.
germination - The active growth of an embryo resulting in the development of a young plant.
gibbosity - Something that bulges out or is protuberant or
projects from a form, plane or margin.
gibbous - With a pouch-like swelling; humped.
glabrous - Without hairs.
gland - A
secreting surface or structure; loosely used for any protuberance or appendage
having the appearence of such an organ, such as calli.
glandula - A term sometimes used for viscidium.
glandular - Bearing glands.
glaucous - Covered with a bloom giving a bluish lustre.
globoid - Globe-like, globular, spherical.
globose - Globular; almost spherical.
globular - Almost spherical.
glutinous - Wet and very sticky.
gynandrium - Another term for the column.
gynoecium - The female parts of a flower.
gynostegium - Another term for the column.
habit - The general appearance of a plant.
habitat - The environment in which a plant grows.
hamulus - A specialised stipe
which is the recurved apex of the rostellum; found in species of Prasophyllum.
haploid - With one set of chromosomes.
head - An inflorescence with the flowers in a tight cluster; for example, Tropidia territorialis.
hemiparasitic - A partially parasitic plant that obtains some nourishment from its host but also photosynthesizes.
hemipollinarium - Half of a pollinarium which is removed as a unit; this structure occurs in orchids which have two viscidia.
herb - A plant which produces a fleshy rather
than a woody stem.
herbaceous - A perennial plant which dies down each year after flowering
(see also deciduous).
herbarium - A
botanical collection of pressed plant specimens.
hermaphrodite - Having male and female parts on a flower.
heteroblastic - Said of orchids which have pseudobulbs consisting of
a single internode.
hirsute - Covered with long spreading coarse hairs.
holomycotrophic - Plant deriving its nutrition solely from a mycorrhizal symbiosis.
homoblastic - Said of orchids which have pseudobulbs consisting of several internodes.
humus - The friable layer on the soil
surface formed from decaying vegetation.
hyaline - Translucent or transparent.
hybrid - The progeny of a cross between two species, cultivars or other hybrids.
hybridisation - The act of crossing flowers to produce hybrids.
hyper-resupinate - When the flowers are twisted at more than 180 degrees.
hypochile - The basal portion
of the labellum.
hypostomatic - With stomata only on the lower surface of the leaf.
imbricate - Overlapping like fish scales.
in ed - Ineditus, unpublished.
incised - Deeply and irregularly cut.
incumbent - Said of an anther which bends forwards during the development of the flower.
incurved - Curved inward.
indehiscent - Not splitting open at maturity.
indeterminate - Said of a growth or
inflorescence when it has no apparent extension limit.
indigenous - Native to a country, region or area.
inflorescence - The flowering structure of a plant.
infrageneric - Refers to any taxon of a rank
below that of genus, such as species, variety, cultivar, etc.
inhibitor - A chemical substance which prevents a growth process.
insectiform - Having the appearance of an insect.
internode - The part of a stem between two nodes.
introrse - Turned
inwards towards the axis.
involute - Margins rolled inwards.
jointed - Bearing distinct joints or nodes.
jump-up - Term used for rocky hills rising out of a plain.
keel - A central dorsal ridge, like
the keel of a boat.
labellum - A lip; in orchids and gingers the highly modified ventral petal that is primarily involved in pollination.
labellum lamina - The expanded
part of the labellum, the broad middle part of the labellum.
lacerate - Appearing as if irregularly cut or torn.
lageniforme - Flask-shaped.
lamina - The expanded part of a leaf or labellum.
lanceolate - Lance-shaped;
longer than wide and tapering at each end, especially the apex.
lanose - Woolly.
larva - The immature stage in an insect; from hatching to pupation.
lateral - Arising at the side of the main axis.
lateral lobe - Side lobe; in orchids with a three-lobed
labellum the basal lobes are called
lateral sepals - Term used
to refer to the two lowermost sepals that extend to the sides, versus the
topmost dorsal sepal.
lax - Loose, drooping, non-turgid.
lead - A horticultural term used by growers for a new growth.
leaf-base - Specialised and expanded basal part of the petiole where it
sheathes the pseudobulb or stem.
leafless - Lacking leaves.
ligneous - Consisting of or having the texture or appearance of wood; woody.
ligulate - Strap-shaped.
limb - The flat expanded portion of a segment.
linear - Long and narrow with parallel sides.
lingulate - Tongue-shaped.
lip - See labellum.
lithophyte - A plant that grows on rocks, boulders, escarpments and cliff faces.
lithophytic - Growing on rocks, boulders, escarpments and cliff faces.
littoral - Growing in communities near the sea.
lobe - A segment of an organ resulting from incision of the margins or division.
lobed - Having one or more lobes.
locule - A compartment of the ovary.
lorate - Strap-shaped.
margin - The border of a leaf.
marginal - Attached to or near the edge.
massulae - Packets or clumps of pollen, can be either monads or tetrads.
mealy - Covered with flour-like powder.
medial - Relating to the middle, ie. a
medial ridge is in the middle of the labellum.
medium - The potting mix in which an orchid is grown, or the mixture on which seeds are raised.
membranous - Like a membrane; thin-textured.
mentum - A chin-like extension at the base of a flower
consisting of the column-foot fused with the bases of the
meristem - The undifferentiated tissue from which new cells are formed, e.g. the tips of roots or stems; the growing tip.
meristematic - Tissue which retains the capacity for further growth.
mesochile - Middle portion
of a labellum.
mesotonic - A term
describing the relationship when the middle of the anther
and pollinia are in close contact with a rostellum or viscidium.
midlobe - The main projecting lobe of a labellum.
midrib - The principal vein that runs the full length of a leaf or segment.
mimicry - A deceitful resemblance between different organisms.
mitra - Column hood
formed by the sterile stamen and/or
monad - A single pollen grain unattached to others; as opposed to a tetrad.
monandrous - With one anther.
moniliform - Having a chain-like series of bumps, swellings or joints that resemble beads on a string.
monocarpic - Flowering and fruiting only once before dying.
monocotyledon - Any Angiosperm which has one seed
leaf and parallel venation in the leaves.
monomorphic - The leaves on the flowering plant are the same form and arrangement as those on the non-flowering plant.
monophyletic - Having a single ancestor.
monopodial - A stem with a single main axis which grows forward at the tip.
monospecific - A genus containing only one species.
monotypic - A genus with a single species.
motile - Capable of independent movement.
mucronate - With a short, sharp apex (or mucro) on a leaf.
multicelled - Having more than one cell.
multiseriate - In several series, rows or whorls.
mycelium - A mass of fungal strands.
mycorrhiza - A beneficial relationship between the roots of a vascular plant and fungi resulting in nutrient exchange.
mycorrhizal - The symbiotic association of the mycelium of a fungus with the roots of certain plants.
mycotrophic - Plant that obtains some or all of its nutrition
through mycorrhizal fungi; another term for saprophytic.
naked - A term used for pollinia which lack any supporting structures such as stipes or caudicles.
naturalised - Established after introduction from another region or country.
nectar - A
sweet fluid secreted from a nectary.
nectar guide - Markings, usually lines or lines of dots, on petals
or the labellum which lead a pollinator to nectar.
nectariferous - Bearing nectar -secreting glands.
nectary - A gland which
nerves - The fine
veins which traverse the leaf-blade.
netted - Venation where the veins join
to form a network (see also anastomosing).
node - A point on the stem where leaves or bracts arise.
nodule - A small, swollen lump on roots; usually applied to legumes but the roots of Apostasia and Tropidia have
unusual fleshy nodule -like structures (see also tubercles).
non-resupinate - An orchid flower which has the dorsal sepal below the lateral sepals and the labellum above the column.
obcordate - Cordate with the broadest part above the middle.
oblanceolate - Lanceolate with the broadest part above the middle.
obloid - Having an oblong shape in solid form, with the cross section circular and the ends rounded.
oblong - Longer than broad, with parallel sides and rounded ends.
obovate - Ovate with the broadest part above the middle.
obovoid - Reverse
egg-shaped in solid form, with the narrow end attached to the stem.
obtrullate - Inversely trullate, with two longer sides meeting at the base.
obtuse - Blunt or
rounded at the apex.
offset - A growth arising from the base of a plant and producing roots while still attached.
opposite - Arising on opposite sides but at the same level.
oppositely - Placed or located directly across from something else or from each other.
orbicular - Circular in outline.
orchidist - A person very interested in orchids and their cultivation.
orchidologist - A person who studies orchids.
orchidology - The study of orchids.
osmophore - A scent-producing gland.
ovary - The part of the gynoecium
which encloses the ovules and after fertilisation
develops into the fruit.
ovate - Egg-shaped in a flat plane.
ovoid - Egg-shaped in solid form.
ovule - The small structure within the ovary which becomes a seed after fertilisation.
pallid - Lacking in radiance or vitality; dull.
palmate - Divided like a hand.
panicle - A much-branched racemose inflorescence.
paniculate - Arranged in a panicle.
papillae - Small, irregular, pimple-like projections or bumps.
papillate - Bearing papillae; the surface is covered with tiny roughened structures, sometimes nipple shaped.
papyraceous - Resembling parchment or paper.
parasite - A plant that derives nourishment directly from another living plant.
parietal - A term applied when the
ovules are attached to the wall of the ovary.
pedicel - The stem which supports a single
flower in an inflorescence.
pedicillate - Of a flower, when it is stalked, borne on a pedicel.
peduncle - The main axis of a compound inflorescence
or the stalk of a solitary flower which subtends the pedicel.
pedunculate - Having a peduncle.
pellucid - Translucent; sometimes applied to a sparkling surface.
peloric - An
abnormality whereby the labellum is of a similar shape and colour to the other petals.
peltate - Circular with the
stalk or petiole attached in the middle on the undersurface.
pendant - Hanging downwards.
pendulous - Hanging down.
penicillate - Brush-like, tufted, in tufts.
perennial - A plant living for more than two years.
perianth - A collective term for the petals and sepals of a
flower, in orchids this does not include the labellum.
perianth segments - A collective term
for the petals and sepals of a flower, in orchids this does not include the labellum.
petal - A segment of the
inner perianth whorl or corolla.
petaloid - With the appearance of a petal; reversions of this type are common in some orchids, for example Diuris spp.
petiolate - Having a petiole.
petiole - The stalk of a leaf.
photosynthesis - The process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source.
phylogeny - The historical or ancestral development of a group of organisms over time.
pillar-box shaped - Narrow with a near-apical opening.
pilose - Bearing long soft hairs.
pistil - A collective term for the female organs of a flower
(stigma, style and ovary).
placenta - The place in the ovaries that bears the seeds.
placentation - The arrangement of
the ovules in the ovary.
plate - Fleshy flat structure on the labellum; callus structure.
pleated - Folded longitudinally.
plicate - Folded longitudinally in pleats.
pollen - The one-celled male spores that are borne in the anther.
pollen scraper - A term used for a
rigid part of the rostellum which directs insect-borne
pollinia into the stigma.
pollinarium - The whole male structure as moved by an insect during
pollination - The
transference of pollen from the anther to the stigma of a flower.
pollinator - An insect that carries pollen from one flower to another.
pollinia - Cogerent or
incoherent structures consisting wholly of aggregated pollen grains.
pollinium - (pl. pollinia) An aggregated coherent mass of pollen grains found in the Orchidaceae and Asclepiadaceae;
usually the contents of an anther cell.
pollinium stalk - A general term referring
to a stalk which attaches the viscidium to the pollinia (see caudicle and stipe).
polymorphic - Consisting of many
forms; a variable species.
polyphyletic - Relating to or characterized by development from more
than one ancestral type.
porrect - Spreading outward and forwards.
proboscis - The tubular sucking mouthparts of insects.
proliferous - Bearing offshoots and other processes of vegetative propagation.
prostrate - Lying flat.
protocorm - Specialised structure that develops after orchid seed germination and from which a shoot develops.
protoembryo - A term used for orchid embryos because they lack any differentiation into tissues.
proximal - Situated near the point of attachment.
pseudobulb - Thickened bulb-like stems of sympodial orchids bearing nodes.
pseudobulbous - Having pseudobulbs.
pseudocopulation - A
type of mimicry whereby flowers
deceive male insects into attempting copulation in order to achieve pollination.
pseudopollen - Starch-rich
cells produced on the labellum of some orchids and which
are collected during pollination.
pseudospur - False spur; spur-like structure formed by the fusion
of the margins of the column foot with the basal margins of the labellum.
pseudowhorled - Having the appearance of being whorled.
pubescent - Softly hairy.
pustulate - Covered with pustules or small blisters.
pyriform - Pear shaped.
quiescent - Period of dormacy between growth spurts.
raceme - A simple unbranched inflorescence with stalked flowers.
racemose - Resembling or borne in a raceme.
rachis - The main axis of a compound leaf or an inflorescence (to which the pedicels or petiolules are attached).
ramiferous - Branched.
recumbent - Said of anthers which are strongly bent so that the
apex is below the level of the base.
recurved - Bent backwards.
reed-stem - Said
of some orchids which have slender leafy stems of uniform thickness, for
example, Conostalix lobbii.
reniform - Shaped like a kidney,
generally wider than long with incurved basal margins.
respiration - The process by which living cells oxidise food compounds to produce energy, water and carbon dioxide.
resupinate - Inverted. In the Orchidaceae, many of the flowers are twisted through 180 degrees, so that the position of the upper and lower petals is reversed. An orchid flower which has the dorsal sepal above the lateral sepals and the labellum below the column.
reticulate - With veins that interconnect like a net.
retinaculum - Another term for a viscidium.
retrorse - Pointed strongly backwards towards the base.
retuse - The apex rounded and with a shallow notch.
revolute - With the margins rolled back.
rhachis - The main axis of a compound leaf
or an inflorescence (to which the pedicels or petiolules are attached).
rhizoids - A slender rootlike filament by which plants attach to the substratum and absorb nourishment.
rhizome - An underground stem with nodes, roots and which can form shoots.
rosette - When the basal leaves radiate
roughly in a circle from a central axis.
rostellar projection - That part of the rostellum
which projects from the column and is contacted by an insect.
rostellum - The area of tissue that separates the stigma from the anther; an adhesive
portion of the stigma which aids pollen transfer.
rostrate - Having a beak.
rugose - Wrinkled.
saccate - Deeply pouched; like a sack.
saprophyte - A leafless (or nearly so)
plant lacking chlorophyll that derives sustenance from decaying wood or other plant parts, in association with a symbiotic fungus.
scale - A dry flattened, papery body; sometimes also used as a term for a rudimentary leaf.
scandent - Climbing.
scape - The peduncle and rhachis of an inflorescence.
scarious - Thin, dry, and membranaceous.
sectile - A term referring to
orchid pollen which is composed of discernible units
secund - Directed towards one side.
seed - A mature ovule containing an embryo and capable of germinating.
seed-coat - The protective covering of a seed; also called testa.
seedling - A young
plant raised from seed which has not yet flowered.
sepal - A segment of the calyx or outer
whorl of the perianth.
sequentially - In a consecutive order, in a sequence.
serrate - With sharp forward-pointing teeth.
serrulate - Having a minutely serrate margin; with tiny teeth.
sessile - Without a stalk, pedicel or petiole.
setae - Stiff hairs, bristles.
setose - Bristly.
sheath - The base of a leaf or bract
which embraces a bud or axis.
shoot - A horticultural term used by growers for a new growth.
simple - Undivided, unbranched; of one piece.
single celled - Having only one cell.
sinker - That section of root which supports a replacement tuber.
sinus - The area between two lobes or segments; in Pterostylis flowers it is used
loosely and refers to the conjoined part of the lateral sepals.
spathulate - Spatula-shaped or spoon-shaped.
speciation - The processes by which species evolve.
species - A taxonomic group of closely related plants all with similar basic features.
spicate - Spike-like, arranged in or resembling a spike.
spike - A simple unbranched inflorescence
with sessile flowers.
spur - A
slender hollow projection from a floral segment (usually the labellum rarely the dorsal sepal); in some orchids spurs are associated with nectaries.
stamen - The male part of a flower producing pollen, consisting of an anther and a
staminode - A sterile stamen; often these are highly
modified as in the column wings of Thelymitra and Pterostylis.
stelidia - A specific
term used for the erect horn-like or tooth-like column wings in members of the Bulbophyllum alliance.
stellate - Star-shaped or of star-like form.
stem - The main supporting axis of a plant.
stem-clasping - Enfolding a stem.
sterile - Not fertile; a plant which is not currently flowering.
sterile bract - A bract which does not subtend a pedicel.
stigma - The enlarged sticky
area which terminates the pistil and is receptive to pollen and allows the pollen grains to germinate.
stigmata - More than one stigma.
stigmatic surface - The sticky receptive
area of the stigma.
stipe - A stalk
derived from the rostellum which attaches the pollinia to the viscidium.
stolonoid - Spreading like a stolon; specialised reproductive
roots in some terrestrial orchids that form clonal colonies.
striae - A thin line or band, especially one of several that are parallel or close together.
stylar canal - A channel from the style into
the ovary through which the pollen tubes grow.
style - The slender part of the pistil which connects the stigma with
the ovary; in orchids the style forms
an indiscernible part of the column.
subcoriaceous - Somewhat leathery.
subgenus - A
subdivision of a genus.
suborbicular - Almost circular.
subsessile - Very shortly stalked.
subsimilar - Somewhat similar.
subtend - To support another structure or organ.
subterranean - Below ground; plants which spend their life cycle below ground.
subulate - Awl-shaped; with a stiff point that
tapers from base to apex.
succulent - Fleshy or juicy.
sucker - A shoot arising from the roots or the trunk below ground level.
sulcate - Furrowed.
suture - The markings lines or ridges on an orchid capsule where it splits at maturity.
symbiont - An organism living cooperatively with a different species.
sympatric - Growing together.
sympodial - A growth habit
whereby each stem has limited growth and new shoots arise from the base of previous ones.
synanthous - Having flowers
and leaves which appear at the same time; inflorescence developing simultaneously with a new shoot.
syndrome - The complex of floral
features which suggests adaptation to a particular pollinator group.
synonym - An
incorrect name which refers a species.
synsepalum - A structure formed by the fusion of two or more sepals.
systematics - The science of classification of organisms.
taxon - A term used to describe any taxonomic
group, for example, genus and species.
taxonomy - The classification and naming of plants or animals.
tegula - A specialised stipe which includes tissue of the rostellum and some layers of the column beneath; found in orchids of the subtribe Sarcanthinae.
tepal - A division of the perianth, a sepal or a petal, in Orchidaceae, this term refers to any sepal or petal, not the labellum.
terete - Round in
cross-section and tapered or cylindrical.
terminal - The apex or end.
terrestrial - Growing in the ground.
tesselate - Grouped like tiles in a pavement.
tetrad - A unit of four pollen grains.
tetragonal - Four-sided, as in the pseudobulbs of Tetrabaculum spp.
theca partitions - The
partitions between the locules in an ovary.
thecal - A case, covering, or sheath,
such as the pollen sac of an anther or the spore case of a moss.
thorax - The body region of
an insect between the head and the abdomen.
three-lobed - Divided into three
lobes, the basal two lobes are known as the lateral lobes and the upper lobe is
called the midlobe.
tomentose - Densely covered with short matted hairs.
transverse - Crosswise.
trichome - A hair-like growth.
trifid - The apex divided into three lobes.
trigonous - Distinctly three cornered and triangular in cross-section.
trilobed - With three lobes.
tripartite - Composed of or divided into three parts.
truncate - As if cut off square at the apex.
tuber - A thickened underground storage organ derived from a root.
tubercle - A smaller tuber-like structure; speacialised root structure in some
Orchidaceae containing mycorrhizal fungi.
tuberculate - Bearing small, wart-like projections.
tunicate - With membranous, sheathing
layers of tissue, such as cover the tubers of many species in the Caladenia alliance.
two-lobed - Deeply divided into two lobes which can remain close together or spread widely apart.
type - In
systematics the reference specimen or collection by
which the identity of a taxon is determined.
umbel - An inflorescence where the flowers radiate from a single point, as in Cirrhopetalum clavigerum.
uncinate - Hooked.
undescribed - A recognised
taxon not yet formally named and described.
undulate - Wavy.
unequal - Of different sizes.
unisexual - Of one sex only; staminate (male) or pistillate (female).
upcurved - The apex curves upwards.
vandoid - Applied to orchids with growth
features resembling a species of Vanda.
variegated - Where the basic
colour of a leaf or petal is broken by areas of another colour, usually white, pale green or yellow.
variety - A
taxonomic subgroup within a species used to differentiate variable populations.
vascular - Said of plants which have water-conducting tissue.
vegetation - The whole plant communities of an area.
vegetative - Asexual development or propagation.
vein - The conducting tissue of leaves.
veinlet - A subdivision or branch of a vein.
velamen - The layer(s) of thick,
spongy cells on the outside of a root; well developed in epiphytic orchids.
velutinous - Velvety,
covered with short soft erect hairs.
venation - The pattern formed by veins.
ventral - On the lower side.
verrucose - Covered with warts or wartlike projections.
versatile - A term used for an anther which
is hinged to the column by an elastic strap and which can pivot on this strap.
vestigial - A nonfunctioning structure that is the remnant of an organ or appendage that was once functional in previous generations or earlier stages of development.
viable - Alive and able to germinate, as of seeds.
villous - Covered with long soft hairs.
viscid - Very sticky or glutinous.
viscidium - A clearly
defined sticky part of the rostellum which is removed
together with the pollinia as a unit.
viscin - Clear elastic threads found in pollinia.
viscous - Very sticky.
whorl - Three or more segments (of leaves, flowers) in a
circle at a node.
whorled - Having or
forming whorls or a whorl.
wing - A
thin, membranous expansion of an organ; in orchid
seeds it can refer to the dry, papery cells which surround the embryo; see also
winged - Having flat projections longitudinally along an axis.
zygomorphic - Asymmetrical and irregular; a flower which cannot be divided equally in more than one plane.