988 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Bristle. A stiff slender appendage likened to a hog's bristle. An awn is a kind 

 of bristle. In grasses the term is applied to the modified branchlets at the 

 base of the spikelets in Setaria and allied genera, and to the prolongation of the 

 rachis in Panicum, sect. Paurochaetium, and a few other groups. 



Bulb. A subterranean bud with fleshy scales like the onion. The so-called bulbs 

 of grasses are conns (which see). Bulbous. Swollen at base like a bulb or 

 corm. Said of the base of the stem of some species of Melica, Phleum, Phalaris, 

 and so on. Bulblets. Small bulbs or corms. Applied also to the proliferous 

 buds in the inflorescence of certain grasses, as Poa bulbosa, proliferous forms of 

 P. arctica, P. alpina, and others. 



Callus. The indurate downward extension of the mature lemma in Stipa, Aris- 

 tida, and some other genera. Morphologically such a callus is a part of the 

 rachilla. In Heteropogon and other Andropogoneae the callus is an oblique part 

 of the rachis which extends downward from the spikelet. In Raphis the callus 

 is a part of the peduncle. The term callus is also applied to the thickened lower 

 joint and first glume of Eriochloa (callus, a thickened part). Callus hairs. 

 The hairs at the base of the floret of Calamagrostis and some other genera. 



Canescent. Gray-pubescent or hairy. 



Capillary. Very slender or hairlike. 



Capitate. In a globular cluster or head. 



Carinate. Keeled. Said of glumes, lemmas, and other parts when flattened 

 laterally, with a sharp keel. 



Cartilaginous. Hard and tough but elastic, like cartilage. 



Caryopsis. The grain or fruit of grasses. The seed coat is grown fast to the 

 pericarp as in the grain of wheat or corn. In a few grasses the seed is free 

 within the pericarp, as in Sporobolus and Eleusine. 



Cespitose. Tufted; several or many stems in a close tuft. 



Chartaceous. Having the texture of writing paper. 



Ciliate. Fringed with hairs on the margin (like an eyelash). Ciliolate. Mi- 

 nutely ciliate. 



Circinate. Coiled from the top downward. 



Clavate. Club-shaped; gradually thickened upward, and more or less circular 

 in cross section. 



Cleistogamous. Applied to flowers or florets when fertilized without opening. 

 Cleistogene. A cleistogamous flower, such as found in Triplasis and Danthonia. 



Collar. The area on the outer side of a leaf at the junction of sheath and blade. 



Column. The lower undivided part of the awns of certain species of Aristida; the 

 lower twisted segment of the awn in Andropogoneae. 



Compact. Said of closely flowered inflorescences. Compare dense. 



Compressed. Flattened laterally, as the compressed spikelets of Uniola latifolia 

 and the compressed sheaths of Andropogon virginicus. If the organ is also 

 sharply keeled, it is said to be compressed-keeled. 



Conduplicate. Folded together lengthwise with the upper surface within, as in 

 the blades of many grasses. 



Continuous. Said of the rachis or other organ which does not disarticulate. The 

 opposite of articulate or disarticulating. 



Contracted. Said of inflorescences that are narrow or dense, the branches short 

 or appressed. The opposite of open or spreading. 



Convex. Rounded on the surface. Said especially of glumes and lemmas that 

 are rounded on the back instead of keelecL 



Convolute. Rolled longitudinally. Said mostly of blades, one edge being inside 

 and the other outside. 



Cordate. Heart-shaped. Said mostly of the base of blades. Cordate-clasping. 

 Heart-shaped at base with the lobes overlapping around the stem. 



Coriaceous. Leathery in texture. 



Corm. The hard swollen base of a stem. In Melica the corm is a single enlarged 

 lower internode. In Panicum bulbosum several internodes are involved. Com- 

 pare bulb. 



Crown. The persistent base of a tufted perennial herbaceous grass. Also the 

 hard ring or zone at the summit of some species of Stipa. The "pappuslike 

 crown" of dissected teeth is mentioned under Pappophorum. 



Culm. The jointed stem of grasses. 



Cuneate. Wedge-shaped with the narrow part below. 



Cuspidate. Tipped with a sharp short rigid point. 



Deciduous. Falling away, as the awn of Oryzopsis, the spikelets of some species 

 with articulate pedicels, and the blades of some bamboos. The opposite of 

 persistent. 



