Sessile. Without a stalk.

Shrub. A bushy, woody growth, usually branched at or near the base, less than 15 feet in height.

Simple. Of one piece; not compound.

Sinuate. Strongly wavy. Page [xiii.]

Sinuous. In form like the path of a snake.

Sinus. The cleft or space between two lobes.

Smooth. Smooth to the touch; not pubescent.

Spatulate. Wide and rounded at the apex, but gradually narrowed downward. Page [xii.]

Spike. A simple inflorescence of sessile flowers arranged on a common, elongated axis (rachis). Page [xiv.]

Spine. A sharp woody outgrowth from a stem.