Gastridium. GRAMINE^E. 275 



panicle pale greenish and tinged with purple, about 6 inches long and 1| broad, the 

 rays in clusters about an inch distant on the common axis, the two or three longest 

 flower-bearing above the middle, the others for their whole length : spikelets 2 lines 

 long : glumes very acute, the lower somewhat longer and terminated by a distinct 

 seta exceeding | line in length, rough on the keel and puberulent all over : floret 

 about ^ shorter than the glumes, bearded at base with a few short white hairs : 

 lower palet truncate, 5-nerved, the lateral nerves projecting as distinct teeth, the 

 central excurrent at or below the middle as a strong bent awn about 2 lines long ; 

 upper palet wanting, or present as a very minute rudimentary scale. Nov. Gen. 



1. 135 ; Trin. Agrost. ii. 74. 



California, locality not given (Bolandcr) ; Mexico. The specimens were received from Mr. 

 Bolander ticketed "A. viridis, tide Munro" : as there is no such published species, A. virescens 

 was probably intended, with the description of which it fairly accords. It has the general aspect 

 as to foliage of the larger forms of A. exarata, Trin., but the panicle is broader and looser than 

 in any form of that. It also differs in its bristle-pointed glumes (an exception in the genus), and 

 its strongly truncate distinctly toothed palet, and (from the awned forms) in the stouter awn 

 placed at the middle of the palet. 



12. A. exigua. Annual; culm (including panicle) 1 to 4 inches high, erect, 

 flattened, very slightly scabrous toward the nodes, sometimes branching from near 

 the base : leaves from an inch to 2 lines long or less, those upon the branches some- 

 times with the blade reduced to a mere point, mostly convolute, roughened on both 

 sides and margins, especially near the apex ; ligule about a line long, acute ; sheaths 

 very loose, strongly striate and minutely scabrous : panicle half the length of the 

 plant, included and at first narrow, at length open ; lower rays about five, the others 

 in pairs, the longer about an inch in length, bearing one to five flowers above the 

 middle, scabrous : spikelets three-fourths of a line long, the pedicels much enlarged 

 just below : glumes not pointed, the lower slightly longer, aculeolate on the keel 

 and with minute scattered hairs all over, especially at the apex, generally tinged with 

 purple : floret of but one palet, equalling the glumes, the callus very minute, with a 

 few hairs ; palet 5-nerved, scabrous with few very minute hairs, very acute at apex, 

 the midnerve prolonged into a roughish awn four lines longer than itself, inserted 

 about one-fifth below the tip of the palet, which is split down to that point forming 

 two setee ; upper palet not manifest or a mere scale : stamens 1 (]). 



Foot-hills of the Sierras, Bolandcr. The specimens accompanied a much reduced form of A. 

 exarata, from which it is abundantly distinct, us it also is from A. canina, 



19. GASTRIDIUM, Beauv. NIT-GRASS. 



Panicle contracted into a somewhat loose tapering spike. Spikelets 1-flowered. 

 Glumes with an enlarged ventricose shining base, very acute above, obscurely keeled, 

 the lower longer. Floret less than one-fourth the length of the lower glume, having 

 a very short callus, which is clothed with minute hairs. Lower palet very thin, 

 truncate and dentate at apex, just below which is a very slender awn equalling or 

 exceeding the glumes (or sometimes absent) ; upper palet equalling the lower. Scales 



2, linear, as long as the ovary. Stamens 3. Stigmas 2, subsessile. 



A genus of a single annual species, considered by some a section of Agrostis, from which it dif- 

 fers mainly in the enlarged shining base of the glumes. 



1. G. australe, Beauv. Culm 6 inches to 2 feet high, smooth, branching at the 

 lower nodes, geniculate below, as are the branches : leaves flat, 2 to 5 inches long, 

 about 2 lines wide, long-pointed, scabrous on both sides, pale green ; sheaths mostly 

 rather shorter than the internodes, slightly roughened ; ligule 2 lines long, lacerate- 

 fringed : panicle 3 to 6 inches in length and about half an inch wide, in large speci- 

 mens somewhat lobed, very pale green, shining with a satiny lustre : spikelets about 

 2 lines long, very acute, the glumes slightly scabrous above, shining below : lower 



