BOUTELOUA CALAMAGROSTIS 347 



(1) Leaves hairy, especially on the margins 



towards the base; axis of spikelet with- 

 out a* tuft of long hairs under the scales 

 and awns B. hirsuta 



(2) Leaves not hairy as a rule ; axis with a tuft 



of hairs under the scales and awns B. oligostdchya 

 b. Glumes smooth 



(1) Spikes 3-6; lemma 4-lobed B.polystdchya 



(2) Spike usually solitary; lemma 3-lobed B.prostrdta 

 2. Spikes many, hanging from the axis, 6-15 mm. 



long; stems 1-4 ft. tall B.curtipendula 



BULBILIS Rafinesque 1819 BUFFALO GRASS 



(Name of doubtful origin) 



PL 46, fig. 1. 



Spikelets 2-3-flowered, staminate spikelets in 2 rows in 1-sided terminal 

 spikes, pistillate spikelets in spike-like clusters of 2-3, mostly hidden in the 

 sheaths, borne on short stems ; glumes unequal, 1 -nerved ; lemma 3-nerved ; 

 glumes of the pistillate spikelets hardened ; monoecious or apparently dioeci- 

 ous perennial spreading by stolons. 

 Stems with staminate flowers 4-12 in. high, with pistil- 

 late flowers .5-3 in. high; staminate spikes 2-3 in a 

 group B. dactyloides 



CALAMAGROSTIS Adanson 1763 REED GRASS 



(Gr. kalamos, reed, agrostis, grass) 



PL 46, fig. 12. 



Spikelets 1-flowered, in panicles, the axis usually extending beyond the 

 flower and hairy; glumes keeled; lemma obtuse, usually long-hairy at base 

 and with an awn on the back, palet shorter, 2-nerved; perennial. 



1. Panicle open, the lower branches long and spread- 



ing 



a. Lemma 2-toothed, about the length of the awn C. canadensis 



b. Lemma 4-toothed C. Scribneri 



2. Panicle dense and spike-like, the branches short, 



ascending or erect 



a. Leaves more or less inrolled, at least above 

 (1) Leaves erect, stiff and sharp-tipped 



(a) Leaves smooth; spikelets 3-4 mm. long C. Suksdorfii 



(b) Leaves very rough; spikelets 5-6 mm. 



long C. purpurdscens 



