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 Pteri-dophyta.

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 amphi-tropous 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.

Sessile

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.