Smooth. Not rough to the touch; cf. glabrous, without hairs, which may be either 



smooth or scabrous. 

 Sari (sorus) . The clusters of sporangia appearing as dots on the back of a leaf of 



a fern. 

 Spadix. The spikelike inflorescence enclosed in a spathe (fig. 788). 

 Spathe. A sheathing lateral organ or pair of organs usually open on one side and 



enclosing an inflorescence (fig. 788). 

 Spatulate. Shaped like a spatula, that is, gradually widening above and rounded at 



the tip (fig. 787). 

 Spheroidal. Shaped like a sphere or ball. 

 Spicate. Arranged in such a way as to resemble a spike. 

 Spike. A type of inflorescence in which the axis is somewhat elongated and the 



flowers are numerous and sessile (figs. 26, 788). 

 Spikelet. The segment of the inflorescence of grasses enclosed by a pair of 



glumes. 

 Spine. A rigid, sharp-pointed structure usually modified from a stem. 

 Spinescent. Bearing spines. 

 Spinose. Bearing spines. 

 Spinule. A diminutive spine. 

 Spore. The reproductive body of pteridophytes and lower plants, analogous to the 



seed. Sporeling: a young plant from germinated spore. Sporiferous: spore-bear- 

 ing. Sporogenous: producing spores. 

 Sporophyll. A spore-bearing leaf. 

 Spreading. Diverging almost to the horizontal; nearly prostrate. Spreading hairs: 



not at all appressed, but erect. Spreading lower lip: diverging from the main 



axis of the flower. 

 Spur. Any hollow, elongate, pointed or blunt outgrowth of the corolla or calyx, as 



in Delphinium (fig. 363). 

 Squamellate. Having a vestiture of scales (fig. 786). 

 Squamellae. Small scales. 

 Squarrose. Having thickly crowded but spreading rigid leaves, bracts, or other 



processes. 

 Stalk. A short or elongate structure bearing or supporting another structure. 

 Stamen. The pollen-bearing organ; usually consisting of the stalk or filament and 



the anther containing the pollen. 

 Staminate. Said of plants or structures bearing stamens and not bearing pistils. 

 Staminodium. A sterile organ in the stamen whorl, presumed to be of staminal 



origin. 

 Standard. The broad, usually upright, petal in a papilionaceous flower such as 



that of the pea (fig. 503). 

 Stellate. Star-shaped; said of hairs or scales that branch in such a manner as to 



radiate from a central point of attachment (fig. 786). 

 Stem. The part of the plant bearing the foliar and floral organs and composed of 



nodes and internodes, or the latter much reduced. 

 Stigma. That part of the pistil that receives the pollen and in which pollination is 



effected (figs. 3a, 3b). 

 Sterile. Not fertile; said of flowers which for any reason are not bearing fruit. 



Sometimes, but not correctly, applied to staminate flowers. 

 Stigmatic. Pertaining to the stigma. 



Stipe. The stalk of an ovary, or, in the Compositae of an achene (fig. 741). 

 Stipitate. Said of glands or of ovaries when they are borne on stalks. 

 Stipule. An appendage frequently occurring at the base of a leaf. 

 Stolon. A stem with elongate internodes that trails along the surface of the 



ground, often rooting at the nodes. See Runner. 



1728 



