1906] Lainson-Scribner, The Genus Sphenopholis 143 



Key to the Species. 



1 Spikelets awnless, rarely with the second floret short-awned, glumes 

 very dissimilar - 



1 Spikelets always awned, flumes not very unlike ... 5 



2 Leaves very narrow or involute-filiform, basal ones often equaling 



the culm, second glume broadly truncate S. fihfonms. 



2 Leaves flat, much shorter than the culm 3 



3 Panicle lanceolate or oblong, spikelets crowded, second glume as 



broad as long, somewhat cuculate in fruit S. ohtumta. 



3 Panicle lax, branches more or less spreading, at least when in 



flower ^ 



4 Glumes nearly ec[ual in length, the second very broadly obovate 



obtuse, florets obtuse, the second one very scabrous all over, 



S. nitida. 



4 Glumes unequal, first shorter than second, florets mostly acute, 



glabrous ^- pal^ens. 



5 Panicle lax, spikelets not crowded, first floret usually awnless 



S. pal list ris. 



5 Panicle narrow spiciform more or less interrupted below . 6 



6 Glumes broadly oblanceolate, first floret with a short straight 



terminal awn ^- ii(Mn. 



(5 Glumes narrowly oblanceolate, awns all alike S. intenupfa. 



» 



Subspecies. 



S. ohtusaia lobata {Trisetum lobatum Trin.). Sheathes and leaves 

 scabrous; panicle cylindrical, spikelets crowded on the short 

 oppressed branches. 



5. obtusata pubescens {Eaionia puhesccns iicribn. & Mcrr.). Sheaths 



and leaves softly pubescent. 



S. nitida glabra {Eatonia glabra Nash.). Sheathes and leaves gla- 

 brous or merely scabrous. 



S. pallens major (Koeleria iruncaia majorTorr.). Panicles narrowly 

 lanceolate or oblong, rather densely flowered, first glume linear 

 nearly equalling the second. 



S. palustris flexuosa n. subsp. Panicle lax the flexuose branches 

 spreading, both lemmas awned. 



S. interrupta californica {Trisetum californicum Vasey). Plants 

 pubescent throughout even to the glumes. 



