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.
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.
Rudimentary, but slightly developed.
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.
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.
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.
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.
Sterile, not producing seed, without a pistil.
Stigma, the upper end of the pistil, adapted for the reception of pollen.
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."
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.