MANUAL OF THE GRASSES OF THE UNITED STATES 79 



Lemmas obtuse, pubescent on the nerves for half or three-fourths their length. 



Dwarf annual 1. P. PARISHII. 



Lemmas glabrous or, if pubescent, the hairs not confined to the nerves. 



Panicles narrow, strict, the branches appressed, mostly with one spikelet; 

 annual, mostly less than 20 cm tall; lemmas acute, more or less pubes- 

 cent 2. P. SIMPLEX. 



Panicles narrow or open, not strict; annual or perennial; lemmas glabrous 01 



pubescent only at base. 



Panicles ellipsoid, rather compact, less than 10 cm long, the branches flor- 

 iferous nearly to base. Lemmas rather coriaceous; culms rather stout. 

 Spikelets 5 to 8 mm long; lemmas 3 to 3.5 mm long __ 3. P. RUPESTEIS. 

 Spikelets 3 to 4 mm long; lemmas 2 to 2.5 mm long. 



4. P. FASCICULATA. 



Panicles pyramidal or elongate, some of the branches naked below, or 



reduced, narrow, and few-flowered. 



Leaves mostly in a short basal tuft, the blades involute, 5 to 10 cm long. 

 Panicle 5 to 10 cm long, open and spreading; lemmas 3.5 mm long, 



glabrous, acute 5. P. LEMMONI. 



Leaves distributed, not in a basal tuft. 



Anthers about 2 mm long. Lemmas 4 to 5 mm long, pubescent at 



base 6. P. MARITIMA. 



Anthers 1 mm long or less. 



Lemmas about 2 mm long; panicle open; the slender branches spread- 

 ing or reflexed. 

 Lemmas broad, obtuse or truncate, not narrowed above; lower 



panicle branches usually reflexed 7. P. DISTANS. 



Lemmas narrow, narrowed into an obtuse apex; panicle branches 



spreading, usually not reflexed 8. P. NUTTALLIANA. 



Lemmas 3 to 4 mm long; panicle narrow, the branches ascending or 



finally spreading. 

 Plants lax, usually 10 to 30 cm tall; panicle 5 to 10 cm long, the 



branches finally spreading 9. P. PUMILA. 



Plants usually 40 to 60 cm tall; panicle 10 to 20 cm long, the 

 branches ascending or appressed 10. P. NUTKAENSIS. 



1. Puccinellia parishii Hitchc. (Fig. 109.) Annual; culms 3 to 

 10 cm tall; blades flat to subin volute, less than 1 mm wide; panicle 

 narrow, few-flowered, 1 to 4 cm long; spikelets 3- to 6-flowered, 3 to 

 5 mm long; lemmas about 2 mm long, obtuse to truncate, 

 scarious and somewhat erose at the tip, pubescent on the 



mid and lateral nerves nearly to the apex, and on the inter- 

 mediate nerves about half way. O Known only from 

 Rabbit Springs, San Bernardino County, Calif. 



2. Puccinellia simplex Scribn. (Fig. 110.) Annual; 

 culms 7 to 20 cm tall; blades narrow, soft, flat; panicle nar- 

 row, about half the length of the entire plant, the branches 

 few, short, appressed, mostly with 1 spikelet; spikelets 6 to 

 8 mm long, appressed; glumes strongly 3-nerved, 1 and 2 

 mm long; lemmas 2.5 mm long, tapering from below the 

 middle to the acute apex, more or less pubescent over the 

 back, o Alkaline soil, California; rare. 



3. Puccinellia rupestris (With.) Fern, and Weath. 

 111.) Annual; culms rather stout, mostly 10 to 20 cm 

 blades flat, 2 to 6 mm wide; panicle ellipsoid, glaucous, 

 rather dense, mostly 3 to 6 cm long, the branches mostly 1<x 



not more than 1.5 cm long, stiffly ascending, floriferous nearly to 

 base ; spikelets 3- to 5-flowered, 5 to 8 mm long, sessile or nearly so; 

 glumes 3- to 5-nerved, 1.5 and 2.5 mm long; lemmas 3 to 3.5 mm 



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