146. Gramineae 323 



9. Leaves pubescent; woods, common nearly throughout 



III. [C. pubescens Muhl., non Poir.] 



C. hirtifolia Mack. 



9. Leaves glabrous. 



10. Pistillate spikes 3-12 nmi long; plants flowering in 



early spring. 



1 1. Staminatc spike stout, 2-4 nun thick; body of the 



perigynium suborbicular, about as long as 



wide ; plants strongly stoloniferous, the stolons 



slender, reddish, fibrillose, .scaly; dry open 



woods, common. [C. hcliophila Mack.] 



--- C. pcnsylvajiica Lam. 



ll.Staminate spike 0.5-2 mm thick; plants forming 

 small tufts, never stoloniferous. 

 12. Mature lea\es 3-5 mm wide; dry woods in 



the northern part of the state 



C. communis Bailey 



12. Matiue leaves 1-2.5 mm wide; dry woods, 

 locally throughout 111. [C. varia of Muhl., 



not Lumn., or Host] C. artitecta Mack. 



10. Pistillate spikes 1-7 cm long. 



13. Leaves involute-filiform, 1-2 mm wide; stems ob- 

 tusely triangular, smooth ; swamps and bogs in 



the northern half of 111 C. lasiocarpa Ehrh. 



13. Leaves flat, 2-6 mm wide; stems sharply triangu- 

 lar, rough above. 

 14. Perigynia 2.5-3.5 mm long, the beak 1 mm 

 long; pi.stillate spikes 5-8 mm thick; style 

 straight, jointed with the achene; swamps, 

 chiefly in the northern and central parts of 



the state C. lanuginosa Michx. 



14. Perigynium 5 mm long, the beak 1.5 mm 

 long; pistillate spikes 8-12 mm thick; style 

 flexuous, continuous with the achene; 

 marshy alluvial soil, Cowford Bridge, 

 Macon Co., June 18, 1915, /. W . Clokey 

 2338, type collection. [C. impressa X 

 lanuginosa Clokey] C. subimpressa Clokey 



146. Gramineae Juss. — Grass Family 

 Key to the Tribes 

 1. SpikeleLs usually more or less laterally compressed, 1 -many- flowered, usually 

 articulating above the persistent glumes. (Subfamily I. Poacoideae) 

 2. Plants woody; stems perennial: leaf-blade (short-) petioled and articu- 

 lated with the sheath Tribe 1. Bambuseae 



2. Plants herbaceous; stems annual; leaf-blade continuous with the sheath. 

 3. Spikelets several-flowered. 



4. Inflorescence a panicle, this sometimes contracted and spike-like. 



