An Illustrated Flora of the Northern United States, Canada and the British Possessions/Glossary of Special Terms



Acaulescent. With stem subterranean, or nearly so.
Accumbent. Cotyledons with margins folded against the hypocotyl.
Achene. A dry one-seeded indehiscent fruit with the pericarp tightly fitting around the seed.
Acicular. Needle-shaped.
Acuinate. Gradually tapering to the apex.
Acute. Sharp pointed
Adnate. An organ adhering to a contiguous differing one; an anther attached longitudinally to the end of the filament.
Adventive. Not indigenous, but apparently becoming naturalized.
Albumen. See Endosperm.
Alliaceous. Onion-like, in aspect or odor.
Alternate. Not opposite; with a single leaf at each node.
Alveolate. Like honeycomb; closely pitted.
Ament. A spike of imperfect flowers subtended by scarious bracts, as in the willows.
Amphibious. At times inhabiting the water.
Amphitropous. Term applied to the partly inverted ovule.
Amplexicaul. Clasping the stem, or other axis.
Anastomosing. Connecting so as to form a well-defined network.
Anatropous. Applied to an inverted ovule with the micropyle very near the hilum.
Androgynous. Flower clusters having staminate and pistillate flowers; in Carex, a spike with upper flowers staminate and lower pistillate.
Angiospermous. Pertaining to the Angiospermae; bearing seeds within a pericarp.
Anther. The part of the stamen which contains the pollen.
Antherid. The male organ of reproduction in Pteridophyta and Bryophyta.
Anthesis. Period of flowering.
Apetalous. Without a corolla.
Aphyllopodic. In Carex, with lower leaves bladeless or with rudimentary leaves only.
Apical. At the top, or referring to the top.
Apiculate. With a minute pointed tip.
Appressed. Lying against another organ.
Arborescent. Tree-like, in size or shape.
Archegone. The female reproductive organ in Pteridophyta and Bryophyta.
Areolate. Reticulated.
Areolation. The system of meshes in a network of veins.
Areole. A mesh in a network of veins.
Aril. A fleshy organ growing about the hilum.
Arillate. Provided with an aril.
Aristate. Tipped by an awn or bristle.
Aristulate. Diminutive of aristate.
Ascending. Growing obliquely upward, or upcurved.
Asexual. Without sex.
Assurgent. See Ascending.
with basal ear-like lobes.
Awn. A slender bristle-like organ.
Axil. The point on a stem immediately above the base of a leaf.
Axile. In the axis of an organ.
Axillary. Borne at, or pertaining to an axil.


Baccate. Berry-like.
Barbellate. Furnished with minute barbs.
Basifixed. Attached by the base.
Berry. A fruit with pericarp wholly pulpy.
Bilabiate. With two lips.
Bipinnate. Twice pinnate.
Bipinnatifid. Twice pinnatifid.
Blade. The flat expanded part of a leaf.
Bract. A leaf, usually small, subtending a flower or flower-cluster, or a sporange.
Bracteate. With bracts.
Bracteolate. Having hractlets.
Bractlet. A secondary bract, borne on a pedicel, or immediately beneath a flower; sometimes applied to minute bracts.
Bulb. A bud with fleshy scales, usually subterranean.
Bulblet. A small bulb, especially those borne on leaves, or in their axils.
Bulbous. Similar to a bulb; bearing bulbs.


Caducous. Falling away very soon after development.
Caespitose. Growing in tufts.
Callosity. A small, hard protuberance.
Callus. An extension of the inner scale of a grass spikelet; a protuberance.
Calyx. The outer of two series of floral leaves.
Campanulate. Bell-shaped.
Campylotropous. Term applied to the curved ovule.
Cancellate. Reticulated, with the meshes sunken.
Canescent. With gray or hoary fine pubescence.
Canaliculate. Channelled; longitudinal1y grooved.
Capitate. Arranged in a head; knob-like.
Capsular. Pertaining to or like a capsule.
Capsule. A dry fruit of two carpels or more, usually dehiscent by valves or teeth.
Carinate. Keeled; with a longitudinal ridge.
Carpel. The modified leaf forming the ovary, or a part of a compound ovary.
Caruncle. An appendage to a seed at the hilum.
Carunculate. With a caruncle.
Caryopsis. The grain; fruit of grasses, with a thin pericarp adherent to the seed.
Caudate. With a slender tail-like appendage.
Caudex. The persistent base of perennial herbs, usually only the part above ground.
Caudicle. Stalk of a pollen-mass in the Orchid and Milkweed Families.
Cauline. Pertaining to the stem.
Cell. A cavity of an anther or ovary.
Chaff. Thin dry scales.
Chalaza. The base of the ovule.
Chartaceous. Papery in texture.
Chlorophyll. Green coloring matter of plants.
Chlorophyllous. Containing chlorophyll.
Ciliate. Provided with marginal hairs.
Ciliolate. Minutely ciliate.
Cilium. A hair.
Cinereous. Ashy; ash-colored.
Circinnate. Coiled downward from the apex.
Circumscissile. Transversely dehiscent, the top falling away as a lid.
Clavate. Club-shaped.
Cleistogamous. Flowers which do not open but are pollinated from their own anthers.
Cleft. Cut about halfway to the midvein.
Clinandrium. Cavity between the anther-sacs in orchids.
Cochleate. Like a snail shell.
Coma. Tuft of hairs at the ends of some seeds.
Commissure. The contiguous surfaces of two carpels.
Conduplicate. Folded lengthwise.
Confluent. Blended together.
Connate. Similar organs more or less united.
Connective. The end of the filament, between the anther-sacs.
Connivent. Converging.
Convolute. Rolled around or rolled up longitudinally.
Coralloid. Resembling coral.
Cordate. Heart-shaped.
Coriaceous. Leathery in texture.
Corm. A swollen fleshy base of a stem.
Corolla. The inner of two series of floral leaves.
Corona; Crown. An appendage of the corolla; a crown-like margin at the top of an organ.
Coroniform. Crown-like.
Corymb. A convex or flat-topped flower-cluster of the racemose type with pedicels or rays arising from different points on the axis.
Corymbose. Borne in corymbs; corymb-like.
Costate. Ribbed.
Cotyledon. A rudimentary leaf of the embryo.
Crenate. Scalloped; with rounded teeth.
Crenulate. Diminutive of crenate.
Crustaceous. Hard and brittle.
Cucullate. Hooded, or resembling a hood.
Culm. The stem of grasses and sedges.
Cuneate. Wedge-shaped.
Cusp. A sharp stiff point.
Cuspidate. Sharp-pointed; ending in a cusp.
Cyme. A convex or flat flower-cluster of the determinate type, the central flowers first unfolding.
Cymose. Arranged in cymes; cyme-like.


Deciduous. Falling away at the close of the growing period.
Decompound. More than once-divided.
Decumbent. Stems or branches in an inclined position, but the end ascending.
Decurrent. Applied to the prolongation of an organ, or part of an organ running along the sides of another.
Deflexed. Turned abruptly downward.
Dehiscence. The opening of an ovary, anther-sac or sporange to emit the contents.
Dehiscent. Opening to emit the contents.
Deltoid. Broadly triangular, like the Greek letter delta, Δ.
Dentate. Toothed, especially with outwardly projecting-teeth.
Denticulate. Diminutive of dentate.
Depauperate. Impoverished, small.
Depressed. Vertically f1attened.
Dextrorse. Spirally ascendmg to the rIght.
Diadelphous. Stamens united into two sets.
Diandrous. Having two stamens.
Dichotomous. Forking regularly into two nearly equal branches or segments.
Dicotyledonous. With two cotyledons.
Didymous. Twin-like; of two nearly equal segments.
Diffuse. Loosely spreading.
Digitate. Diverging, like the fingers spread.
Dimorphous. Of two forms.
Dioecious. Bearing staminate flowers or antherids on one plant, and pistillate flowers or archegones on another of the same species.
Discoid. Heads of Compositae composed only of tubular flowers, rayless; like a disk.
Disk. An enlargement or prolongation of the receptacle of a flower around the base of the pistil; the head of tubular flowers in Compositae.
Dissected. Divided into many segments or lobes.
Dissepiment. A partition-wall of an ovary or fruit.
Distichous. Arranged in two rows.
Distinct. Separate from each other; evident.
Divaricate. Diverging at a wide angle.
Divided. Cleft to the base or to the mid-nerve.
Dorsal. On the back, or pertaining to the back.
Drupaceous. Drupe-like.
Drupe. A simple fruit, usually indehiscent with fleshy exocarp and bony endocarp.
Drupelet. Diminutive of drupe.


Echinate. Prickly.
Ellipsoid. A solid body, elliptic in section.
Elliptic. With the outline of an ellipse; oval.
Emarginate. Notched at the apex.
Embryo. A rudimentary plant in the seed.
Embryo-sac. The macrospore of the flowering plants, contained in the ovule.
Endocarp. The inner layer of the pericarp.
Endogenous. Forming new tissue within.
Endosperm. The substance surrounding the embryo of a seed; albumen.
Ensiform. Shaped like a broad sword.
Entire. Without divisions, lobes, or teeth.
Ephemeral. Continuing for only a day or less.
Epigynous. Adnate to or borne on the upper part of the ovary.
Epiphytic. Growing on other plants, but not parasitic.
Equitant. Folded around each other; straddling.
Erase. Irregularly margined, as if gnawed.
Evanescent. Early disappearing.
Evergreen. Bearing green leaves throughout the year.
Ex-current. With a tip projecting beyond the main part of the organ.
Exfoliating. Peeling off in layers.
Exocarp. The outer layer of the pericarp.
Exogenous. Forming new tissue outside the older.
Exserted. Prolonged past surrounding organs.
Exstipulate. Without stipules.
Extrorse. Facing outward.


Falcate. Scythe-shaped.
Farinaceous. Starchy, or containing starch.
Fascicle. A dense cluster.
Fascicled. Borne in dense clusters.
Fastigiate. Stems or branches which are nearly erect and close together.
Fenestrate. With window-like markings.
Fertile. Bearing spores, or bearing seed.
Fertilization. The mingling of the contents of a male and female cell.
Ferruginous. Color of iron-rust.
Fetid. Ill-smelling.
Fibrillose. With fibres or fibre-like organs.
Filament. The stalk of an anther; the two forming the stamen.
Filamentous. Composed of thread-like structures; thread-like.
Filiform. Thread-like.
Fimbriate. With fringed edges.
Fimbrillate. Minutely fringed.
Fistular. Hollow and cylindric.
Flabellate. Fan-shaped, or arranged like the sticks of a fan.
Flaccid. Lax; weak.
Flexuous. Alternately bent in different directions.
Floccose. With loose tufts of wool-like hairs.
Foliaceous. Similar to leaves.
Foliolate. With separate leaflets.
Follicle. A simple fruit dehiscent along one suture.
Follicular. Similar to a follicle.
More or less pitted.
Free. Separate from other organs; not adnate.
Frond. The leaves of ferns.
More or less shrub-like.
Fugacious. Falling soon after development.
Fugitive. Plants not native, but occurring here and there, without direct evidence of becoming established.
Funiculus. The stalk of an ovule or seed.
Fusiform. Spindle-shaped.


Galea. A hood-like part of a perianth or corolla.
Galeate. With a galea.
Gametophyte. The sexual generation of plants.
Gamopetalous. With petals more or less united.
Gemma. A bud-like propagative organ.
Gibbous. Enlarged or swollen on one side.
Glabrate. Nearly without hairs.
Glabrous. Devoid of hairs.
Gladiate. Like a sword-blade.
Gland. A secreting cell, or group of cells.
Glandular. With glands, or gland-like.
Glaucous. Covered with a fine bluish or white bloom; bluish-hoary.
Globose. Spherical or nearly so.
Glomerate. In a compact cluster.
Glomerule. A dense capitate cyme.
Glumaceous. Resembling glumes.
Glume. The scaly bracts of the spikelets of grasses and sedges.
Granulose. Composed of grains.
Gregarious. Growing in groups or colonies.
Gynaecandrous. In Carex, a spike with upper flowers pistillate and lower staminate.
Gynobase. A prolongation or enlargement of the receptacle, supporting the ovary.


Habit. General aspect.
Habitat. A plant's natural place of growth.
Hastate. Halberd-shaped; like sagittate, but with the basal lobes diverging.
Haustoria. The specialized roots of parasites.
Head. A dense round cluster of sessile or nearly sessile flowers.
Herbaceous. Leaf-like in texture and color; pertaining to an herb.
Hilum. The scar or area of attachment of a seed or ovule.
Hirsute. With rather coarse stiff hairs.
Hispid. With bristly stiff hairs.
Hispidulous. Diminutive of hispid.
Hyaline. Thin and translucent.
Hypocotyl. The rudimentary stem of the embryo; also termed radicle.
Hypogynium. Organ supporting the ovary in some sedges.
Hypogynous. Borne at the base of the ovary, or below.
Hyponym. A generic or specific name untypified.


Imbricated. Overlapping.
Imperfect. Flowers with either stamens or pistils, not with both.
Incised. Cut into sharp lobes.
Included. Not projecting beyond surrounding parts.
Incumbent. With the back against the hypocotyl.
Indehiscent. Not opening.
Indusium. The membrane covering a sorus.
Inequilateral. Unequal sided.
Inferior. Relating to an organ which arises or is situated below another.
Inflexed. Abruptly bent inward.
Inflorescence. The flowering part of plants; its mode of arrangement.
Integument. A coat or protecting layer.
Internode. Portion of a stem or branch between two successive nodes.
Introrse. Facing inward.
Involucel. A secondary involucre.
Invollucellate. With a secondary involucre.
Involucrate. With an involucre, or like one.
Involucre. A whorl of bracts subtending a flower or flower-cluster.
Involute. Rolled inwardly.
Irregular. A flower in which one or more of the organs of the same series are unlike.


Labiate. Provided with a lip-like organ.
Laciniate. Cut into narrow lobes or segments.
Lanceolate. Considerably longer than broad, tapering upward from the middle or below; lance-shaped.
Latex. The milky sap of certain plants.
Leaflet. One of the divisions of a compound leaf.
Legume. A simple dry fruit dehiscent along both sutures.
Lenticular. Lens-shaped.
Ligulate. Provided with or resembling a ligule.
Ligule. A strap-shaped organ, as the rays in Compositae.
Limb. The expanded part of a petal, sepal, or gamopetalous corolla.
Linear. Elongated and narrow with sides nearly parallel.
Lineolate. With fine or obscure lines.
Lobed. Divided to about the middle.
Lament. A jointed legume, usually constricted between the seeds.
Loculicidal. Applied to capsules which split longitudinally into their cavities.
Lodicules. Minute hyaline scales subtending the flower in grasses.
Lunate. Crescent-shaped.
Lyrate. Pinnatifid, with the terminal lobe or segment considerably larger than the others.


Macrosporange. Sporange containing macrospores.
Macrospore. The larger of two kinds of spores borne by a plant, usually giving rise to a female prothallium.
Marcescent. Withering but remaining attached.
Medullary. Pertaining to the pith or medulla.
Mericarp. One of the carpels of the Carrot Family.
Mesocarp. The middle layer of a pericarp.
Micropyle. Orifice of the ovule, and corresponding point on the seed.
Microsporange. Sporange containing microspores.
Microspore. The smaller of two kinds of spore borne by a plant, usually giving rise to a male prothallium; pollen-grain.
Midvein (Midrib). The central vein or rib of a leaf or other organ.
Monadelphous. Stamens united by their filaments.
Moniliform. Like a string of beads.
Monoecious. Bearing stamens and pistils on the same plant, but in different flowers.
Monstrous. Unusual or deformed.
Mucronate. With a short sharp abrupt tip.
Mucronulate. Diminutive of mucronate.
Muricate. Roughened with short hard processes.
Muticous. Pointless, or blunt.


Naked. Lacking organs or parts which are normally present in related species or genera.
Naturalized. Plants not indigenous to the region, but so well established as to have become part of the flora.
Nectary. A sugar-secreting organ.
Node. The junction of two internodes of a stem or branch, often hard or swollen, at which a leaf or leaves are usually borne.
Nodose. Similar to nodes or joints; knotty.
Nodulose. Diminutive of nodose.
Nut. An indehiscent one-seeded fruit with a hard or bony pericarp.
Nutlet. Diminutive of nut.


Obcordate. Inversely heart-shaped.
Oblanceolate. Inverse of lanceolate.
Oblong. Longer than broad with the sides nearly parallel, or somewhat curving.
Obovate. Inversely ovate.
Obovoid. Inversely ovoid.
Obsolete. Not evident; gone, rudimentary, or vestigial.
Obtuse. Blunt, or rounded.
Ochreae. The sheathing united stipules of Polygonaceae.
Ochreolae. The ochreae subtending flowers in the Polygonaceae.
Ochroleucous. Yellowish white.
Oösphere. The cell of the archegone which is fertilized by spermatozoids.
Operculate. With an operculum.
Operculum. A lid.
Orbicular. Approximately circular in outline.
Orthotropous. Term applied to the straight ovule, having the hilum at one end and the micropyle at the other.
Ovary. The ovule-bearing part of the pistil.
Ovate. In outline like a longitudinal section of a hen's egg.
Ovoid. Shaped like a hen's egg.
Ovule. The macrosporange of flowering plants, becoming the seed on maturing.


Palate. The projection from the lower lip of two-lipped personate corollas.
Palet. A bract-like organ enclosing or subtending the flower in grasses.
Palmate. Diverging radiately like the fingers.
Panicle. A compound flower cluster of the racemose type, or cluster of sporanges.
Paniculate. Borne in panicles or resembling a panicle.
Papilionaceous. Term applied to the irregular flower of the Pea Family.
Papillose. With minute blunt projections.
Pappus. The bristles, awns, teeth, etc., surmounting the achene in the Chicory and Thistle Families.
Parasitic. Growing upon other plants and absorbing their juices.
Parietal. Borne along the wall of the ovary, or pertaining to it.
Parted. Deeply cleft.
Pectinate. Comb-like.
Pedicel. The stalk of a flower in a flower-cluster, or of a sporange.
Peduncle. Stalk of a flower, or a flower-cluster, or a sporocarp.
Pedunculate. With a peduncle.
Peltate. Shield-shaped; a flat organ with a stalk on its lower surface.
Penicillate. With a tuft of hairs or hair-like branches.
Perfect. Flowers with both stamens and pistils.
Perfoliate. Leaves so clasping the stem as to appear as if pierced by it.
Perianth. The modified floral leaves (sepals or petals), regarded collectively.
Pericarp. The wall of the fruit, or seed-vessel.
Perigynium. The utricle enclosing the ovary or achene in the genus Carex.
Perigynous. Borne on the perianth, around the ovary.
Peripheral. Pertaining to the periphery.
Persistent. Organs remaining attached to those bearing them after the growing period.
Petal. One of the leaves of the corolla.
Petaloid. Similar to petals; petal-like.
Petiolate. With a petiole.
Petiole. The stalk of the leaf.
Phyllode. A bladeless petiole or rachis.
Phyllopodic. In Carex, with lower leaves of the fertile culms normally blade-bearing.
Pilose. With long soft hairs.
Pinna. A primary division of a pinnately compound leaf.
Pinnate. Leaves divided into leaflets or segments along a common axis.
Pinnatifid. Pinnately cleft to the middle or beyond.
Pinnule. A division of a pinna.
Pistil. The central organ of a flower containing the macrosporanges (ovules).
Pistillate. With pistils; and usually employed in the sense of without stamens.
Placenta. An ovule-bearing surface.
Plicate. Folded into plaits, like a fan.
Plumose. Resembling a plume or feather.
Plumule. The rudimentary terminal bud of the embryo.
Pollen. Pollen-grain. Contents of the anther. See Microspore.
Pollinia. The pollen-masses of the Orchid and Milkweed Families.
Polygamous. Bearing both perfect and imperfect flowers.
Polypetalous. With separate petals.
Pome. The fleshy fruit of the Apple Family.
Procumbent. Trailing or lying on the ground.
Prophylla. Bractlets.
Prothallium. The sexual generation of Pteridophyta.
Puberulent. With very short hairs.
Pubescent. With hairs.
Punctate. With translucent dots or pits.
Pungent. With a sharp stiff tip.
Pyriform. Pear-shaped.


Raceme. An elongated determinate flower-cluster with each flower pedicelled.
Racemose. In racemes, or resembling a raceme.
Rachilla. The axis of the spikelet in grasses.
Rachis. The axis of a compound leaf, or of a spike or raceme.
Radiant. With the marginal flowers enlarged and ray-like.
Radiate. With ray-flowers; radiating.
Radicle. The rudimentary stem of the embryo; hypocotyl.
Radicular. Pertaining to the radicle or hypocotyl.
Raphe (Rhaphe). The ridge connecting the hilum and chalaza of an anatropous or amphitropous ovule; the ridge on the sporocarp of Marsilea.
Ray. One of the peduncles or branches of an umbel; the flat marginal flowers in Compositae.
Receptacle. The end of the flower stalk, bearing the floral organs, or, in Compositae, the flowers; also, in some ferns, an axis bearing sporanges.
Virgate. Wand-like.
Recurved. Curved backward.
Reflexed. Bent backward abruptly.
Regular. Having the members of each part alike in size and shape.
Reniform. Kidney-shaped.
Repand. With a somewhat wavy margin.
Reticulate. Arranged as a network.
Retrorse. Turned backward or downward.
Refuse. With a shallow notch at the end.
Revolute. Rolled backward.
Rhachis. See Rachis.
Rhizome. See Rootstock.
Ringent. The gaping mouth of a two-lipped corolla.
Rootstock. A subterranean stem, or part of one.
Rostellum. Beak of the style in Orchids.
Rostrate. With a beak.
Rosulate. Like a rosette.
Rotate. With a flat round corolla-limb.
Rugose. Wrinkled.
Runcinate. Sharply pinnatifid, or incised, the lobes or segments turned backward.


Sac. A pouch, especially the cavities of anthers.
Saccate. With a pouch or sac.
Sagittate. Like an arrow-head, with the lobes turned downward.
Samara. A simple indehiscent winged fruit.
Saprophyte. A plant which grows on dead organic matter.
Scabrous. Rough.
Scale. A minute, rudimentary or vestigial leaf.
Scape. A leafless or nearly leafless stem or peduncle, arising from a subterranean part of a plant, bearing a flower or flower-cluster.
Scapose. Having scapes, or resembling a scape.
Scarious. Thin, dry, and translucent, not green.
Scorpioid. Coiled up in the bud, unrolling in growth.
Secund. Borne along one side of an axis.
Segment. A division of a leaf or fruit.
Sepal. One of the leaves of a calyx.
Septate. Provided with partitions.
Septicidal. A capsule which splits longitudinally into and through its dissepiments.
Serrate. With teeth projecting forward.
Serrulate. Diminutive of serrate; serrate with small teeth.
Sissile. Without a stalk.
Setaceous. Bristle-like.
Setose. Bristly.
Silicle. A silique much longer than wide.
Silique. An elongated two-valved capsular fruit, with two parietal placentae, usually dehiscent.
Sinuate. With strongly wavy margins.
Sinuous. In form like the path of a snake.
Sinus. The space between the lobes of a leaf.
Sorus (Sori). A group or cluster of sporanges.
Spadiceous. Like or pertaining to a spadix.
Spadix. A fleshy spike of flowers.
Spathaceous. Resembling a spathe.
Spathe. A bract, usually more or less concave, subtending a spadix.
Spatulate. Shaped like a spatula; spoon-shaped.
Spermatozoids. Cells developed in the antherid, for the fertilization of the oosphere.
Spicate. Arranged in a spike; like a spike.
Spike. An elongated flower cluster or cluster of sporanges, with sessile or nearly sessile flowers or sporanges.
Spikelet. Diminutive of spike; especially applied to flower-clusters of grasses and sedges.
Spinose. With spines or similar to spines.
Spinule. A small sharp projection.
Spinulose. With small sharp processes or spines.
Sporange. A sac containing spores.
Spore. An asexual vegetative cell.
Sporocarp. Organ containing sporanges or sori.
Sporophyte. The asexual generation of plants.
Spreading. Diverging nearly at right angles; nearly prostrate.
Spur. A hollow projection from a floral organ.
Squarrose. With spreading or projecting parts.
Stamen. The organ of a flower which bears the microspores (pollen-grains).
Staminodium. A sterile stamen, or other organ in the position of a stamen.
Standard. The upper, usually broad, petal of a papilionaceous corolla.
Stellate. Star-like.
Sterigmata. The projections from twigs, bearing the leaves in some genera of Pinaceae.
Sterile. Without spores, or without seed.
Stigma. The summit or side of the pistil to which pollen-grains become attached.
Stipe. The stalk of an organ.
Stipitate. Provided with a stipe.
Stipules. Appendages to the base of a petiole, often adnate to it.
Stipulate. With stipules.
Stolon. A basal branch rooting at the nodes.
Stoloniferous. Producing or bearing stolons.
The transpiring orifices in the epidermis of plants.
Strict. Straight and erect.
Strigose. With appressed or ascending stiff hairs.
Strophiole. An appendage to a seed at the hilum.
Strophiolate. With a Strophiole.
Style. The narrowed top of the ovary.
Stylopodium. The expanded base of a style.
Subacute. Somewhat acute.
Subcordate. Somewhat heart-shaped.
Subcoriaceous. Approaching leathery in texture.
Subfalcate. Somewhat scythe-shaped.
Subligneous. Somewhat woody in texture.
Subterete. Nearly terete.
Subulate. Awl-shaped.
Subversatile. Partly or imperfectly versatile.
Succulent. Soft and juicy.
Sulcate. Grooved longitudinally.
Superior. Applied to the ovary when free from the calyx; or to a calyx adnate to an ovary.
Suture. A line of splitting or opening.
Symmetrical. Applied to a flower with its parts of equal numbers.
Syncarp. A fleshy multiple or aggregate fruit.


Tendril. A slender coiling organ.
Terete. Circular in cross section.
Ternate. Divided into three segments, or arranged in threes.
Tetradynamous. With four long stamens and two shorter ones.
Thallus. A usually flat vegetative organ without differentiation into stem and leaves.
Thyrsoid. Like a thyrsus.
Thyrsus. A compact panicle.
Tomentose. Covered with tomentum.
Tomentulose. Diminutive of tomentose.
Tomentum. Dense matted wool-like hairs.
Torsion. Twisting of an organ.
Tortuous. Twisted or bent.
Tracheae. The canals or ducts in woody tissue.
Tracheids. Wood-cells.
Triandrous. With three stamens.
Tricarpous. Composed of three carpels.
Trimorphous. Flowers with stamens of three different lengths or kinds; in three forms.
Triquetrous. Three-sided, the sides channeled.
Truncate. Terminated by a nearly straight edge or surface.
Tuber. A thick short underground branch or part of a branch.
Tubercle. The persistent base of the style in some Cyperaceae; a small tuber.
Tuberculate. With rounded projections.
Turbinate. Top-shaped.


Uliginous. Inhabiting mud.
Umbel. A determinate, usually convex flower-cluster, with all the pedicels arising from the same point.
Umbellate. Borne in umbels; resembling an umbel.
Umbellet. A secondary umbel.
Umbelloid. Similar to an umbel.
Uncinate. Hooked, or in form like a hook.
Undulate. With wavy margins.
Urceolate. Urn-shaped.
Utricle. A bladder-like organ; a one-seeded fruit with a loose pericarp.


Valvate. Meeting by the margins in the bud, not overlapping; dehiscent by valves.
Vascular. Relating to ducts or vessels.
Vein. One of the branches of the woody portion of leaves or other organs.
Veinlet. A branch of a vein.
Velum. A fold of the inner side of the leafbase in Isoetes.
Velutinous. Velvety; with dense fine pubescence.
Venation. The arrangement of veins.
Vernation. The arrangement of leaves in the bud.
Versatile. An anther attached at or near its middle to the filament.
Verticillate. With three or more leaves or branches at a node; whorled.
Vestigial. In the nature of a vestige or remnant.
Villous. With long soft hairs, not matted together.


Whorl. A group of three similar organs or more, radiating from a node. Verticil.
Whorled. See Verticillate.
Winged. With a thin expansion or expansions.