(2 GRAMINEAE. 



node the central perfect or polygamous, the two lateral sometimes imperfect, 

 1 to many flowered, when many flowered the uppermost flowers imperfect. 



A. Spikelets sessile. 

 SpikeletS solitary at the nodes of the rachis. 



Flowers 1 or _' ill a Bpikelet; spike slender, the spikelets deeply sunk in notches of the 

 rachis. -Subtribe Lkptureae. 



Bractlet awnless; callus naked 40. Lepturus. 



Bractlet awned; callus hairy 41. Scribneria. 



Flowers 3 or more in a spikelet. — Subtribe Triticeak. 



Spikelets placed edgewise to the rachis, so that the backs of one row of bractlets are 



turned toward the notch; bract 1 only, except in the terminal spikelet 



42. Lolium. 

 Spikelets placed flatwise to the rachis so that one side of each row of bractlets is 



turned toward the notch; bracts 2 to each spikelet 43. Aghopykon. 



Spikelets -' or more side by side at the nodes of the rachis. — Subtribe Elymeae. 

 Flowers 2 or more in each spikelet; rachis joined at the nodes or not. 



Bracts but little smaller than the bractlets 44. Elymus. 



Bracts minute, or obsolete and leaving only scars 45. Aspkrella. 



Flowers solitary in each spikelet; rachis jointed at the nodes, each internode at 



maturity falling away with the attached spikelet 46. HORDEUM. 



B. Spikelets, at least the lateral ones, pedicellate. 



Flowers 2 or more in each spikelet; rachis jointed at the nodes or not 44. Elymus. 



Flowers solitary in each spikelet; rachis jointed at the nodes, each internode at 

 maturity falling away with the attached .spikelet 46. Horkdtm. 



40. LEPTURUS R. Br. Hard-grass. 

 Ours slender, branching annuals. Inflorescence a simple, terminal, slender, 

 cylindrical, jointed spike, at maturity each internode separating with the 

 attached spikelet. Spikelets sessile, distichous, alternate, solitary in the 

 notches of the axis, their backs turned towards the notches; uppermost spike- 

 let terminal. Bracts 1 or 2, exceeding the bractlet, approximate in the lower, 

 opposite in the upper spikelet, sub-equal, hard and rigid, narrow, 5-nerved, 

 acute, awnless, one spreading when in flower. Flowers 2, or 1 with an empty 

 bractlet above it. Bractlets sub-equal, hyaline, acute (in ours), awnless. 

 Palea 2-nerved. Scales entire, glabrous. Stamens 3 or fewer. (Greek leptos, 

 slender, oura, tail, referring to the slender, tail-like spikes.) 



1. L. cylindricus Trin. Cylindrical Hard-grass. Stems 12 to 14 in. 

 high; spike 3 to 6 in. long, stout, cylindrical, straight; lateral spikelets with 

 only 1 brad ; bractlets acute. 



Native of the Mediterranean Region; naturalized along the coast near San 

 Francisco, .lime. July. 



2. L. incurvatus (L.) Trin. Curved Hard-grass. Usually has a more 

 Blender, incurved spike, with the lateral spikelets subtended by 2 bracts. 



An alien weed, native of the Mediterranean Region: San Francisco; Mar- 

 tine/; Pt. Reyes. June-July. 



41. SCRIBNERIA Hackel. 



A low. Blender, erect, tufted annual. I nlloreseeiiee a slrict, slender, jointed 



spike, breaking up at maturity. Spikelets L-flowered, sessile and half em- 

 bedded in the notches of the rachis, solitary or rarely in pairs, alternate, long 

 and slender. Bracta much exceeding the bractlet, persistent, unequal, linear- 

 lanceolate, acute, awnless, eccentrically keeled, very rigid; upper 3 to 5- 

 aerved, lower 2 to 3 nerved and ribbed. Rachilla very short, jointed above the 



. with a ring of hairs surrounding the base of the bractlet, prolonged as a 

 minute hairy point. I '.i art let and palea sub equal, keeled; brnrtlet ehartaeeous, 

 I nerved, toothed at apex and hearing a stout awn about its own length from 





