268 GR AMINES. Vilfa. 



Texas. A perennial species, varying so greatly with the locality that it is not practicable to indi- 

 cate any well-defined varieties. Specimens from the high Sierras are very dwarf, with capillary 

 culms ; those collected at Tejon Pass by Mr. Blake are like those from Northern Mexico, a tangled 

 mass of long flexuose filiform and very tough culms. This appears to be the form assumed by 

 the plant in the southern localities, where it is much sought after by the Mexicans, who use it for 

 stuffing their large leathern aparejos, or pack-saddles, a purpose to which its toughness and elas- 

 ticity especially adapt it. It was this use of it which led Dr. Torrey to give the name V. utilis. 



2. V. gracillima. Culms annual, capillary, smooth, much branched at base, 

 forming small dense tufts, 3 to 12 but usually about 6 inches high, the leafy por- 

 tion about 2 inches high : leaves 6 to 9 lines long and less than a line broad, flat, 

 involute at apex, very minutely scabrous on the upper side and margins ; ligule 

 about a line long, obtuse and lacerate, decurrent ; sheaths equalling the internodes, 

 loose, striate, smooth with hyaline margins : panicle long-exserted, narrowly linear, 

 few-flowered, interrupted below ; rays in pairs or threes, erect, appressed, 1 - 3-flow- 

 ered : spikelets about a line long, on shorter pedicels : glumes subequal, or the 

 upper larger, membranaceous, colorless, very obtuse, distinctly 1 -nerved, mucronate 

 or erose-toothed at apex, about half as long as the oblong-lanceolate floret, which has 

 a small callus : palets about equal, blackish, the lower 3-nerved, with a few very 

 minute hairs on the nerves below, mucronate or tipped with a small seta. 



In the Sierra Nevada, in wet soil, at 11,000 feet altitude (Brewer) ; Yosemite Valley (Bolandcr) ; 

 also collected by Mrs. Austin and Lemmon, and near Santa Barbara by Mrs. Cooper; Oregon, 

 Hall. This occurs in dense moss-like tufts 2 or 3 inches across, the bright green foliage being 

 about two inches high ; above this the numerous depauperate panicles are borne by wiry shining 

 naked culms, scarcely larger than a horse-hair. At first taken for a variety of V. dcpauperata, 

 Torr., but its habit and annual root abundantly distinguish it from any of the many forms of that 

 species ; with V. cuspidata, Torr., and one or two other species, it approaches closely to Mulilcn- 

 bergia. 



16. SPOBOBOLUS, R. Br. DROP-SEED GRASS. 



Panicle usually open and pyramidal, sometimes contracted with erect rays. Spike- 

 lets 1-flowered. Glumes chartaceo-membranaceous, 1-nerved or nerveless, mostly 

 obtuse, awnless, the lower one smaller. Floret without callus and longer than the 

 glumes. Palets similar in texture to the glumes. Scales 2. Stamens 2 or 3. 

 Grain globular, the seed loose within the usually hyaline pericarp, which ultimately 

 bursts and allows it to fall away. 



Annuals and perennials, widely distributed ; there are 7 species in the Atlantic States. There 

 is much confusion in different works as to Sporobolus and Vilfa, some authors adopting the one 

 or the other name, according to their views of priority, and not admitting that there are two 

 genera. Dr. Gray long ago (Manual) adopted the free or adherent seed as a sufficient generic dis- 

 tinction, placing those species having a spiked panicle and the fruit a true caryapsis, the seed 

 adherent to the pericarp, in Vilfa, while those with the generally open panicle and the fruit a 

 utricle, i. e. the seed free from the (usually) hyaline pericarp, are included in Sporobolus. This 

 arrangement is followed here. The pericarp usually bursts spontaneously when quite ripe ; in 

 immature specimens a brief soaking of the fruit in water will cause the separation to take place. 



* Spikelets a line long : glumes very unequal. 



1. S. cryptandrus, Gray. Culms 2 or 3 feet high, usually geniculate and 

 branched below : leaves flat, about 2 lines wide, acuminate, scabrous especially 

 above ; ligule a mere fringe ; sheaths smooth, strongly bearded at throat, the lower 

 shorter than the internodes : panicle narrowly pyramidal, more or less inclosed by 

 the upper sheath, 4 to 8 inches long, its rays mostly in pairs, spreading, flower- 

 bearing to the base and sometimes hairy in the axils : spikelets 1 line long, short- 

 pedicelled, rather crowded, lead-colored : glumes somewhat acute, the upper twice 

 the length of the very narrow lower one : floret equalling the upper glume. Manual, 

 2 ed. 542 (5 ed. 610). Agrostis cryptandra, Torr. in Ann. Lye. N. York, i. 151. 

 Vilfa cryptandra, Trin. Agrost. i. 47; Steud. Syn. Gram. 156; Watson, Bot. King 

 Exp. 375. 



