R

Raceme, a flower-cluster of lateral flowers, each on a pedicel of its own.

Racemose, in racemes; resembling a raceme.

Radiate, spreading from a centre; bearing ray-florets.

Radical, proceeding from the base of the stem.

Ray, the branch of an umbel: the circle of marginal florets in a composite flower, as distinguished from the disk.

Receptacle, the enlarged top of the flower-stalk.

Recurved, curved backward.

Reflexed, bent backward or downward.

Regular, with all the parts of the organ of the same size and shape.

Reniform, kidney-shaped.

Repand, with a margin resembling that of an expanded umbrella.

Reticulate, in the form of a network.

Retuse, with a shallow notch at the end.

Revolute, rolled backward from the margin.

Rhachis, the axis of a frond or compound leaf. Rhizome, an underground stem; a rootstock.

Rib, one of the main veins of a leaf.

Ringent, wide open, gaping.

Rootstock, an underground stem.

Rotate, wheel-shaped.

Rudimentary, but slightly developed.

Rugose, wrinkled.

Runcinate, with teeth on the margin pointing backward.

Runner, a thread-like prostrate branch, proceeding from the base of a stem, and rooting at the extremity.

S

Saccate, sac-shaped.

Sagittate, arrow-shaped, the basal lobes directed downward. Salver-shaped, with a border spreading at right angles to the tube. Samara, a winged fruit, as that of the Ash.

Scabrous, rough.

Scape, a leafless peduncle rising from the ground or near it.

Scarious, thin, dry, and membranaceous.

Scurf, small rusty-looking scales on the epidermis.

Segment, one of the parts of a divided leaf.

Sepal, a division of a calyx.

Septum, a partition.

Serrate, toothed, the teeth directed towards the apex.

Serrulate, finely serrate. Sessile, without a stalk. Setaceous, bristle-like. Setose, beset with bristles. Sheath, a tubular envelope. Sheathing, enclosing as with a sheath. Shrub, a woody perennial smaller than a tree.

Silicle, a short and broad silique.

Silique, the peculiar pod of a Cruciferous flower.

Simple, of one piece.

Sinuate, wavy.

Sinus, the indentation between two lobes.

Sorus, a cluster of sporangia.

Spadix, a spike on a fleshy axis.

Spathe, a bract, subtending or enveloping a spadix.

Spathulate, gradually narrowed downward from a rounded apex.

Spicate, in the form of a spike.

Spike, a cluster of sessile flowers on a more or less elongated axis.

Spikelet, a small or secondary spike. Spindle-shaped, larger in the middle than at either end.

Spine, a sharp woody outgrowth of the stem.

Spinose, spine-like, or beset with spines.

Sporangium, a spore-case.

Sporocarp, the fruit-case of certain cryptogams.

Spur, a hollow projection.

Squarrose, having spreading tips.

Stamen, a pollen-bearing organ.

Standard, the upper petal of a papilionaceous corolla.

Stellate, star-shaped.

Sterile, not producing seed, without a pistil.

Stigma, the upper end of the pistil, adapted for the reception of pollen.

Stigmatic, stigma-like.

Stipe, the leaf-stalk of a Fern: the stalk supporting a pistil in certain flowers.

Stipular, relating to stipules.

Stolon, a branch which roots.

Stoloniferous, bearing stolons.

Striate, marked with fine longitudinal lines.

Strict, rigid and upright.

Strigose, beset with appressed sharp straight and stiff hairs.

Style, the narrow part of a pistil between the ovary and the stigma.

Stylopodium, a disk-like expansion at the base of a style, as in Umbelliferous plants.

Sub-, a prefix meaning "somewhat."

Subulate, awl-shaped.

Succulent, juicy.

Suffrutescent, slightly shrubby.

Suffrutlcose, low and woody, diminutively shrubby.

Sulcate, grooved or furrowed. Superior (calyx), attached to the ovary.

Suture, a seam or line of dehiscence.

Symmetrical, with sets having the same number of parts each, or a multiple of that number.