MANUAL OF THE GRASSES OF THE UNITED STATES 489 



The species with rhizomes often form extensive colonies to the ex- 

 clusion of other plants. They are important soil binders and soil 



builders in coastal and interior marshes. A 



European species, S. townsendi H. and J. Groves, 

 has 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 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 very 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 spike- 

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



mostly comparatively short 3. S. LEIANTHA. 



Inflorescence less dense, the spikes more slender, less crowded, the spike- 

 lets not curved, the inflorescence with no suggestion of a twist. 



4. S. ALTERNIFLORA. 



Blaaes 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 rnizomes absent (see also S. patens var. caespitosa); plants in large 

 hard tufts with tall culms (1.5 to 2 m) and long slender blades. 



6. S. BAKERI. 

 Creeping rhizomes present (except in S. patens var. caespitosa) ; plants usually 



less than 1 m tall. 

 Spikelets crowded, the spikes mostly thick, erect; Western States. 



7. S. GRACILIS. 



Spikelets less crowded, the spikes relatively slender, ascending; Atlantic 

 seacoast 8. S. PATENS. 



1. Spartina pectinata Link. PRAIRIE CORDGRASS. (Fig. 1038.) 

 Culms 1 to 2 m tall, firm or wiry; blades elongate, flat when 

 fresh, soon involute in drying, as much as 1.5 cm wide, very scabrous 

 on the margins; spikes mostly 10 to 20, sometimes fewer or as many 

 as 30, mostly 4 to 8 cm long, ascending, sometimes appressed, rarely 

 spreading, on rather slender peduncles; glumes hispid-scabrous on 

 the keel, the first acuminate or short-awned, about as long as the 

 floret, the second exceeding the floret, tapering into an awn as much 

 as 7 mm long; lemma glabrous except the scabrous keel, 7 to 9 mm 

 long, the apex with two rounded teeth; palea usually a little longer 

 than the lemma. 91 (S. michauxiana Hitchc.) Fresh- water 

 marshes, Newfoundland and Quebec to eastern Washington and 

 Oregon, south to North Carolina, Kentucky, Illinois, Arkansas, 

 Texas, and New Mexico ; in the Eastern States extending into brackish 

 marshes along the coast (fig. 1039). 



2. Spartina cynosuroides (L.) Roth. BIG CORDGRASS. (Fig. 1040.) 

 Culms 1 to 3 m tall, stout, the base sometimes as much as 2 cm thick; 

 blades flat, 1 to 2,5 cm wide, very scabrous on the margins; spikes 



