Prickly

With prickles.

Prostrate

Lying flat on the ground.

Puberulent

With very short hairs; minutely pubescent.

Pubescent

With hairs.

Punctate

With translucent or colored dots or depressions.

Pungent

Sharp pointed.

Pyriform

Pear-shaped.

Raceme

An inflorescence with flowers borne on pedicels of equal length, and arranged on an elongated axis.

Rachis

The axis of a compound leaf.

Rank

A row; 2-ranked meaning in 2 rows.

Recurved

Curved backward or downward.

Reflexed

Bent sharply backward.

Reniform

Kidney-shaped and broader than long.

Repand

With a slightly uneven and somewhat sinuate margin.

Resinous

Having resin.

Reticulate

Arranged as in a network.

Retrorse

Turned backward or downward.

Retuse

With a shallow notch at a rounded apex.

Revolute

Rolled backward from the edge.

Rhizome

A horizontal underground stem, usually rooting at the nodes and becoming erect at the apex.

Rosette

A cluster of prostrate leaves having a radially symmetrical arrangement.

Rostrate

Bearing a beak.

Rugose

Wrinkled.

Runcinate

Sharply pinnatifid or incised, the lobes or segments turned backward.

Sagittate

Shaped like an arrowhead, the basal lobes pointing downward.

Samara

A winged fruit, a key.

Scabrous

Rough to the touch when rubbed in at least one direction.

Scale

A small, rudimentary leaf.

Scarious

Thin, dry, and translucent, not green.

Scurfy

Covered with small bran-like scales.

Segment

One of the parts of a cleft or divided blade.

Serrate

With sharp teeth pointing forward.

Serrulate

Finely serrate, the teeth small and shallow.

Sessile

Without a petiole or stalk.

Seta

A bristle.

Sheath

The tubular lower part of a leaf enclosing the stem.

Sheathing

Enclosing as by a sheath.

Shrub

A low woody growth which usually branches near the base; a bush.

Sinuate

With a strongly wavy margin.

Sinus

The space between two lobes of a blade.

Spatulate

Spatula-shaped or spoon-shaped.

Spine

A sharp outgrowth from the stem.

Spinulose

With small, sharp spines.

Spreading

(Of pubescence) The hairs erect, suberect, or ascending.

Spur-Shoots

Short stubby branches with greatly crowded leaf scars and very slow growth.

Stalk

The unexpanded, basal part of a leaflet.

Stellate

(Of pubescence) With three or more radiating branches from the ends of the hairs.

Sterigmata

Very small leaf stalks of certain conifers.

Stipule

One of a pair of appendages at the base of a petiole, often adnate to it.

Stipule-Scar

Small marks or lines left by deciduous stipules.

Stolon

A runner, or any basal branch that roots at the nodes.

Stoloniferous

With stolons.

Striate

Marked with fine longitudinal lines.

Strigose

With appressed or ascending stiff hairs.

Subacuminate

Somewhat acuminate.

Subacute

Acutish, somewhat acute.

Suborbicuiar

Nearly orbicular.

Subpinnatifid

Nearly pinnatifid.

Subulate

Awl-shaped.

Succulent

Juicy.

Superposed

Said of extra buds which appear above the true axillary buds; usually flower buds.

Tapering

Gradually becoming smaller in diameter or width toward one end.

Tendril

A long, slender, coiling structure serving as the organ of attachment in some climbing plants.

Terete

Circular in cross section.

Terminal

Applied to the end bud beyond which no further growth takes place normally until the following season.

Ternate

Divided into three segments; 3-foliate.

Thorn

A stiff, woody sharp-pointed structure which represents a modified branch.

Tomentose

Densely pubescent with soft, matted hairs.

Truncate

Ending abruptly as if cut off transversely.

Tuber

A thick, short, underground branch or part of a branch, with many buds.

Tuberous

With tubers.

Umbel, An inflorescence with the flowers arising at the same point.

Umbo

A small scar on the apophysis of a cone scale of a conifer.

Unarmed

Without thorns, spines, or prickles.

Undulate

With a wavy margin; repand.

Valvate

Said of buds in which the scales merely meet at the edges without overlapping.

Valve

One of the parts into which a capsule splits.

Verticillate

With three or more leaves at a node; whorled.

Villous

With long, soft hairs, not matted together.

Viscid

Sticky.

Whorl

A group of three or more similar leaves arising from a node.

Winged

(Of stems, petioles, or rachises) Flattened structures projecting out along the sides.