Sapwood
The outer and lighter wood that is actively transporting water.
Scabrous
Rough texture due to short stiff hairs or the epidermal cells.
Scale
A small dry bract acting as a covering or layer.
Scale-like
Having small overlapping layers.
Schizocarp
A dry dehiscent fruit that breaks apart into two halves.
Scurfy
Covered with small bran-like scales.
Serrate
Sharp forward-pointing teeth along leaf margin.
Serrulate
Many minute sharp forward-pointing teeth along leaf margin.
Sessile
Attached directly without a stalk; a leaf or flower directly attached to a stem.
Shoot
A young green stem.
Shrub
A small woody plant with multiple stems from the ground and that is not usually climbable; all of the branches are produced from or near the base.
Simple
A single undivided leaf. A simple leaf may have lobes, or serrations (See also Compound).
Sinuate
Strongly wavy margins only in one plane; close to being lobulate (See also Undulate).
Sinus
On a lobed leaf a sinus is the valley between the lobes; they can vary greatly in size and shape.
Spatulate
Spoon or spatula-shaped, with a rounded leaf blade that tapers to the base.
Spike
An inflorescence that is unbranched with sessile flowers maturing from the bottom up.
Spine
A hard sharp woody growth that emerges from below the epidermis and is either a modified leaf or stipule (See also Thorn).
Spinose
Bearing spines along leaf margins, Tiny spines at nodes on stems.
Spinose
Having spines; having sharp woody growths.
Spirally Arranged
The actual pattern of alternate leaves on a stem;
Spur
A short shoot with leaves or fruit. Ex. Ginkgo; A hollow projection from a flower either in the sepals or petals.
Stalk
A supporting structure for a leaf, flower, or fruit.
Stamen
The male part of a flower typically consisting of an anther and filament; Commonly referred to as the androecium. (See also Pistil)
Stem
Supportive structure for buds, leaves, and nodes; can be single or branched; sometimes found underground.
Sterile
Barren or infertile; not able to produce seed.
Stigma
The recepticle for pollen on the pistil.
Stipule
A bract or appendage at the base of a petiole (usually found in pairs).
Stolon
A horizontal stem that roots at the nodes and tip and can produce a new plant (See also Rhizome and Tiller).
Strobile
A cone or an inflorescence resembling a cone. Ex. Alders
Style
The tube that connects the stigma and ovary of the pistil (the female part of the flower).
Subopposite
Leaves appear near opposite but slightly skewed at a node without a fascicle (See also Opposite and Alternate).
Superposed
Appearing one right above another; an accessory bud found above the true bud.
Symmetric
A balanced appearance; Having the same number of floral parts in any angle.