MANUAL OF THE GRASSES OF THE UNITED STATES 509 



in recent years assumed much importance, especially in southern England, the 

 Netherlands, and northern France, as a soil builder along the coast where it 

 is reclaiming extensive areas of marsh land. The marsh hay of the Atlantic 

 coast, much used for packing and formerly for bedding, often consists largely 

 of S. patens. 



Blades usually more than 5 mm. wide, flat when fresh, at least at base, the tip involute; 

 plants mostly robust and more than 1 m. tall. 

 First glume nearly as long as the floret, slender-acuminate, the second with an awn as 

 much as 7 mm. long; spikes somewhat distant, mostly more or less spreading. 



1. S. PECTINATA. 



First glume shorter than the floret, acute, the second acute or mucronate but not slender- 

 awned; spikes approximate, usually appressed. 

 Blades ver}^ scabrous on the margins; glumes strongly hispid-scabrous on the keels. 



2. S. CYNOSUROIDES. 



Blades glabrous throughout or minutely scabrous on the margins; glumes glabrous or 

 usually softly hispidulous or ciliate on the keels. 

 Inflorescence dense and spikelike, the spikes closely imbricate; the spikelets mostly 

 somewhat curved, giving a slightly twisted effect; blades mostly comparatively 



short .3. S. foliosa. 



Inflorescence less dense, the spikes more slender, less crowded, the spikelets not 



curved, the inflorescence with no suggestion of a twist 4. S. alterniplora. 



Blades less than 5 mm. wide (rarely more in S. gracilis); involute (sometimes flat in S. 

 gracilis); plants mostly slender and less than 1 m. tall (taller in S. bakeri). 



Inflorescence dense, cylindric; spikes numerous 5. S. spartinae. 



Inflorescence not cylindric; spikes not more than 10, usually fewer. 



Creeping rhizomes absent (see also S. caespitosa) ; plants in large hard tufts with culms 



1.5 to 2 m. tall and long slender blades 6. S. bakeri. 



Creeping rhizomes present (except occasionally in S. caespitosa); plants usually less 

 than 1 m. tall. 



Second glume 12 to 16 mm. long, aristate 7. S. caespitosa. 



Second glume less than 10 mm. long, acute. 



Blades usually flat; glumes conspicuously hispid-ciliate on the keels; spikes several, 



appressed 8. S. gracilis. 



Blades usually involute; glumes scabrous on the keels; spikes few, ascending to 

 spreading 9. S. patens. 



1. Spartina pectinata Link. 

 Prairie cordgrass. (Fig. 741.) Texas, and New Mexico; in the 

 Culms 1 to 2 m. tall, firm or wiry; Eastern States extending into brack- 

 blades elongate, flat when fresh, soon ish marshes along the coast. 

 involute in drying, as much as 1.5 2. Spartina cynosuroides (L.) 

 cm. wide, very scabrous on the Roth. Big cordgrass. (Fig. 742.) 

 margins; spikes mostly 10 to 20, Culms 1 to 3 m. tall, stout, the base 

 sometimes fewer or as many as 30, sometimes as much as 2 cm. thick; 

 mostly 4 to 8 cm. long, ascending, blades flat, 1 to 2.5 cm. wide, very 

 sometimes appressed, rarely spread- scabrous on the margins; spikes nu- 

 ing, on rather slender peduncles; merous, ascending, approximate, of- 

 glumes hispid-scabrous on the keel, ten dark-colored, usually more or less 

 the first acuminate or short-awned, peduncled, mostly 3 to 8 cm. long; 

 nearly as long as the floret, the second spikelets about 12 mm. long; glumes 

 exceeding the floret, tapering into an acute, hispid-scabrous on the keel, 

 awn as much as 7 mm. long; lemma the first much shorter than the floret, 

 glabrous except the scabrous keel, the second longer than the floret, 

 7 to 9 mm. long, the apex with 2 sometimes rather long-acuminate; 

 rounded teeth; palea usually a little lemma not toothed at apex; palea a 

 longer than the lemma. % (S. little longer than the lemma. % 

 michauxiana Hitchc.) — Fresh-water (S. polystachya (Michx.) Beauv. (S. 

 marshes, Newfoundland and Quebec cynosuroides var. polystachya Beal) 

 to eastern Washington and Oregon, has been differentiated on its strictly 

 south to North Carolina, Arkansas, maritime habitat, but morphological 



