GLOSSARY 569 
Pubescent. Covered with short, soft, and down-like hairs. 
Raceme. An elongated simple flower cluster with each flower pedi- 
celled. 
Rachis. The axis of a spike or a raceme, or of a compound leaf. 
Ray. One of the flower stalks of an umbel; the strap-shaped marginal 
flowers in the Composite. 
Receptacle. The more or less expanded end of the stem which bears 
the organs of a flower, or, in the Composite, the collection of flowers 
in a head. 
Recurved. Curved downward or backward. 
Reflexed. Bent abruptly downward or backward. 
Regular. Having the members of each part alike in form and size. 
Revolute. Rolled backward from the margin or apex. — 
Rib. A primary or prominent vein in a leaf. 
Rootstock. An underground, bud-bearing stem. 
Scape. A naked or nearly leafless flower-stalk arising directly from 
the crown of the root. 
Scarious. Thin, dry, and membranous, not green. 
Segment. One of the divisions of a lobed or cleft leaf, or other organ 
of a plant. 
Sepal. One of the divisions of a calyx. 
Serrate. With sharp, forward-pointing teeth. 
Sessile. Without a footstalk of any kind. 
Sheath. A tubular envelope, as the lower part of the leaf in grasses. 
Silicle. A short silique. 
Silique. The pod peculiar to the Cruciferae. 
Simple. Not compound. : 
Sinuate. Wavy-edged. 
Sinus. The cleft or space between two lobes. 
Spadix. A flower spike having a fleshy axis. 
Spathe. A large bract or a pair of bracts inclosing a spadix or a flower 
cluster. 
Spatulate. Narrowing gradually toward the base from a rounded apex. 
Spike. An elongated flower cluster with flowers sessile or nearly so 
upon its axis. 
Spine. A sharp and rigid outgrowth from the stem of a plant. 
Spur. A tubular or sac-like extension of some part of a flower, usually 
nectar-bearing. 
Stamen. One of the pollen-bearing organs of a flower. 
Stem. The main ascending axis of a plant. ; 
Sterile. Unproductive, as a flower without a pistil, or a stamen with- 
out an anther. 
