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 Composites. 

 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 Cruciferoe. 

 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. 



