Sagittate - Resembling an arrowhead in shape.
Samara - A winged fruit that does not split spontaneously. (e.g. maple).
Scale - A small, usually dry leaf that is closely pressed against another organ.
Scape - A leafless flower stalk that grows from the ground.
Sepal - A leaf or division of the calyx.
Serrate - Saw-toothed, with the teeth pointing toward the apex.
Sessile - Having no stalk.
Sheath- an expanded or tubular structure that partially encloses a stem or other organ.
Shoot - A stem or branch and its leaves, especially when young.
Shrub - A woody plant that produces no trunk but branches from the base.
Simple - Not compounded (leaves) or branched (stems, flower clusters).
Smooth - Not rough (compare glabrous).
Solitary - Not growing as part of a cluster or group.
Spadix - A fleshy spike.
Spathe - One or two bracts enclosing a flower cluster. (especially a spadix).
Spatulate - Shaped like a spoon, with a narrow end at the base.
Spike - A flower cluster in which sessile flowers grow along part of the length of the peduncle.
Spikelet - A small spike, particularly one of the few-flowered spikes making up the inflorescence of a grass.
Spore - A one-celled reproductive body produced by relatively primitive plants.
Spur - A slender, hollow projection from a petal or sepal.
Stamen - The male or pollen-bearing organ of a flower.
Strobile - A cone or cone-like structure.
Style - The slender, elongated part of a pistil.
Suture - A natural seam or groove along which a fruit splits.
Taproot - A single main root that grows vertically into the ground.
Terminal - Occurring at or growing from the end opposite the base. (compare lateral).
Ternate - Occurring in threes or divided into three parts.
Trifoliate - Having three leaves.
Trifoliolate - Having three leaflets.
Tripinnate - Descriptive of a pinnate leaf having pinnate leaflets with pinnate pinnules.
Tuber - A thick, fleshy part, usually of a rootstock.