4 GRAMINEAE. 



bractlel shorter, broader and more turgid than in L. perenne, terminating in 

 .-in ;i\\n :is long as the spikelet, or sometimes short-awned or awnless (var. 

 arvense Byrne); in other respects Bimilar to L. perenne. 



Naturalized from Europe: Berkeley; San Francisco; Antioch; Pt. Eeyes and 

 elsewhere as a weed in waste places. May. 



43. AGROPYRON J. Gaertn. Wheat-crass. 

 Ours perennials with very short ligule. Inflorescence a simple, slender, stiff 

 ami erect spike. Spikelets 3 to many-flowered, large, solitary, sessile, inserted 

 broadside or somewhat obliquely to the rachis, distichous, compressed. Bracts 

 not equaling the nearest bractlet, unequal, lanceolate or linear, many-nerved. 

 Bractlel coriaceous, 5 to 7-nerved. Palea hyaline, flattened, usually ciliate- 

 keeled. Scales ovate, entire, ciliate. Stamens 3. Ovary hairy at the apex; 

 styles very short, distinct; stigmas distant, feathery. Achene hairy at apex. 

 (Greek name for some allied grass, from agros, field, puros, wheat, — hence 

 field- or wild-wheat.) 



Bractlet long-awned. 



Bracts awnless; awns of bractlet 8 to 18 lines long 1. A. scabrum. 



Bracts shortly awned; awn of bractlet 6 to 7 lines long 2. A. richardsoni. 



Bractlel awnless or with a very short awn; bracts more than 53 the length of the spikelet. 



Etootstock tufted, not stoloniferous 3. A. tenerum. 



Uootstock long, slender, running and stoloniferous 4. A. arenicolum. 



1. A. scabrum Beauv. Australian Wheat-grass. Stems stout, erect, 

 - to .'5 ft. high; blades short, involute, smooth below; spike 8 to 16 in, long; 

 spikelets 10 to 14 in number, 1 to 1% in. long excluding awns, narrow, (i to 10- 

 flowered, the longest % to iy 2 in. apart; bracts about 7 lines long, awnless. 

 cartilaginous, pale green, with broad, scarious margins, smooth or minutely and 

 sparsely Bcabrid, slriate; bractlet chartaceous. with a broad, scarious margin, 

 minutely Bcabrid; awn 8 to 18 lines long, mostly flexuous and widely divergent. 



A pale glaucous Australian species, sparingly naturalized in California: 

 San Jose, etc. 



2. A. richardsonii (Trin.) Schrad. Richardson's Wheat-grass. Stems 

 stout, sub-solitary, erect, 3 to 3% ft. high; blades 2 to 6 in. long, 2 1 /> lines 

 wide, setaceous-pointed, scabrous above, smooth below; spike 5 to 7 in. long- 

 lowest spikelets about */> in. apart; spikelets (5 to 7 lines long without the 

 awn, ."! to 4-floweredj bracts 5 to 7 lines long without the awn, scabrous on the 

 many nerves, their awns about 2% lines long; awn of the bractlet (! to 7 



lilies lollg. erect. 



Oakland (II. X. Bolander) ; probably introduced, apparently not since col- 

 lected. July. 



3. A. tenerum Vasey. Slender Wheat-grass. Rootstock tufted, not 

 stoloniferous; stems slender, erect, from a slightly ascending, leafy base, 14 to 

 L'o in. high; blades 1 to 6 in. long, 1 to \.% lines wide, flat, rough; spike 3% 

 to .". in. long; spikelets L3 to L6; bracts more than % the length of the spikelet, 

 awnless or nun pointed, glabrous, scabrouslv cilia te, broadest below the middle. 



\ . repens \ ar. tenerum I leal. | 



San Mateo | II. N. Inlander ) . 



4. A. arenicolum Davy. Dink Whea.t-gka.ss. Rootstock long, slender, 



Creeping and BtoloniferoUB; stems 6 in. high, erect or arcuate at base, clothed 

 with dead sheaths below; branches int ra\ aginal ; sheaths glabrous; ligule re- 

 duced to a ring ';: line long; blades convolute, glabrous below, above clothed 



with a Bparse pubescence and deeply channeled, 6 to 10 in. long, 2 lines wide, 



