GRAMINE^. (grass FAMILY.) 



873 



acuminate, crowded leaves; culms branching at base, with scattered 

 longer leaves. Spikes 4-7, .02 to .05 long, green or purplish — All 

 the year — Waste places, especially in sandy soil; everywhere. A 

 most troublesome weed. 



4§. TETRAPOGON, Desf. Tetrapogon. 

 Spikelets on the outer face of a flattened rachis, 2-ranked, 3-4 



Fig. 307. 



Spike of Tetrapogon 

 villosum. 



flowered, the lower two flowerets perfect, the others 

 tabescent, consisting of one pale. Glumes 2, persist- 

 ent, membranous, keeled, the lower acuminate, the 

 upper rounded at tip, aristate-mucronate. Lower 

 pale keeled, 3-nerved, obtuse or retuse, long-awned 

 just below tip; upper pale retuse, 2-keeled — Peren- 

 nials ; spikelets in 2, erect spikes, adnate by their 

 inner face, appearing to form one, 4-ranked spike. 



T. villosum, Desf. 21 .2 to .3, tufted; root- 

 stock thickish, with a dense rosette of leaves ; culms 

 erect, sparingly leafy. Leaves glabrous, linear, 

 channeled, the radical somewhat 2-ranked, crowded. 

 Spikes .04 to .06 long, .015 thick (including crowd- 



silky-hairy at back, obtuse or retuse at tip, with an 

 awn twice to four times as long — Spring — Valleys 

 about Dead Sea, and southward to Sinai and 

 Egypt. 



49. DACTIXOCTEKTIUHI, Willd. Egyptian Grass. 



Spikelets arranged along the outer aspect of the flattened rachis, 

 alternate, sessile, laterally compressed, 2-oo -flowered, the flowerets, ex- 

 cept the uppermost which is tabescent, perfect. Glumes nearly equal, 

 keeled, membranous, shorter than flowerets, the upper mucronate- 

 aristate at or a little below tip; upper pale 2 keeled. Aonuals; spikes 

 digitate. 



D. iElgyptiacum; L. Egyptian Grass. Rijl-el-BarMyeh. 

 Na'im-es-SaUb. A to .6; culms prostrate below, geniculate, rooting at 

 joints, branching. Spikes 3-5, .05 long, .005 broad, mucronate by ex- 

 currence of rachis; lower glume oblong, acute to acuminate, upper 

 ovate, larger, rounded at tip, retuse, with an awn as long as itself in 

 the notch; lower pale mucronate-aristate, the lateral nerves obsolete — 

 Spring — Sidon (Gaill. in Fi. Or.). 



50. PAPPOPHORUM, Schreb. 

 Pappophoiium. 



Spikelets laterally compressed, 2-3-flowered, 

 the lowest floweret perfect, the upper staminate 

 or neuter. Glumes lanceolate, many-nerved, 

 muticous, longer than flowerets. Lower pale 

 somewhat leathery, concave, 9-nerved, the nerves 

 excurrent in straight, subulate awns. Upper pale 

 membranous, 2-keeled, retuse — Tufted annuals 

 or perennials, with spike-like panicle. 



P. Foxii, Post. 0? .06 to .1, jDubescent; 

 culms geniculate-ascendiug. Leaves narrow- 

 linear, convolute, mouth of sheath short-bearded. 

 Panicle cylindrical, ,02 to .03 long, .006 broad; 



113 



(a) Spikelet of P. Foxii. 



(b) Lower pale 6 diameters. 



