148 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Section 2. Pteroessa Doell 



Rachilla of spikelet continuous, not disarticulating at maturity; 



palea usually persistent for a short time after the fall of the 



lemma (sometimes falling with it in E. unioloides and E. chariis). 



10. Eragrostis reptans (Michx.) Nees. (Fig. 283.) Annual, 



dioecious; culms branching, creeping, rooting at the nodes, forming 



mats; blades flat, usually pubescent, mostly 1 to 3 cm long; panicles 



numerous, ovoid, usually rather dense or capitate, few- to several- 



*3 



Figure 283. — Eragrostis reptans. 



Pistillate (9) and staminate (cf) plants, X H; floret, X 10. (Bush 

 1306 (9) and 1307 (cf), Tex.) 



flowered, rarely many-flowered, mostly 1 to 2 cm long; spikelets 

 several- to many-flowered, linear, at length elongate and more or less 

 curved; lemmas closely imbricate, often sparsely villous, acuminate, 

 about 3 mm long; palea of pistillate floret about half as long as the 

 lemma, of the staminate floret as long as the lemma; grain ovoid, 

 about 0.5 mm long; anthers before dehiscing, 1.5 to 2 mm long, o 

 (E. capitata Nash.) — River banks, sandy land, and open ground, 

 Kentucky to South Dakota and Texas (fig. 284). 



11. Eragrostis hypnoides (Lam.) B. S. P. 

 (Fig. 285.) Annual, branching, creeping, and 

 matlike as in the preceding ; blades scabrous or 

 pubescent on the upper surface; panicles el- 

 liptic, loosely few-flowered, 1 to 5 cm long, 

 sometimes somewhat capitate; spikelets 

 several- to many-flowered, linear, mostly 5 to 

 10 mm long, sometimes as much as 2 cm long 

 in a dense cluster; flowers perfect; lemmas glabrous, acute, 1.5 to 2 mm 

 long; palea about half as long as the lemma; grain 0.5 mm long; anthers 

 about 0.2 mm long, o — Sandv river banks and wet ground, Quebec 

 to Washington, south through Mexico and the West Indies to Argen- 

 tina; not found in the Rocky Mountains (fig. 286). 



12. Eragrostis simplex Scribn. (Fig. 287.) Annual; culms spread- 

 ing to suberect, 10 to 30 cm tall; blades flat, 1 to 3 mm wide; panicle 

 narrow, 5 to 20 cm long, the main axis often curved, the branches 



Figure 284.— Distribution of 

 Eragrostis reptans. 



