5(4). Panicle mostly less than 3 cm. broad: spikes only 5 to 30 per panicle; 



rhizomes soft; culms 6-15 dm. long 2. S. altemiflora. 



5. Panicle mostly more than 3 cm. broad; spikes usually 25 to 45 per panicle; 



rhizomes firm; culm firm and tough, 9-30 dm. long 



3. 5. cynosuroides. 



1. Spartina spartinae (Trin.) Hitchc. Sacahuista, Gulf cordgrass. Fig. 124. 



Tufted perennial; lowermost internodes occasionally shortly subrhizomatous 

 toward the outside of the large tuft but true rhizomes absent; culms numerous, 

 5-20 dm. long, 2.4 mm. thick, erect, unbranched; ligule 1-2 mm. long; blades 

 2-7 dm. long, 2-5 mm. broad at the base, closely involute essentially the entire 

 length, the tips sharp and spinelike; panicle spikelike, 6-40 cm. long, 5-9 mm. 

 thick, usually tapered to both ends; spikes 10 to 75 per panicle, 10-35 mm. long, 

 3-4 mm. thick, closely appressed and overlapping; spikelets 16 to 40 per spike, 

 5-8 mm. long; first glume 2-6 mm. long; second glume 4-8 mm. long; lemma 

 about equaling second glume; keels of glumes and lemma minutely hispid. 



Abundant in tight loamy somewhat saline poorly drained flats, marshes, swamps 

 and wet coastal prairies, in s.e. Tex. and Rio Grande Plains, extremely abundant 

 near the coast, rare and scattered inland (e.g. Gonzales Co.), spring-summer, 

 rarely fall; Gulf and Carib. shores, U.S., Mex. and C.A.; also inland in S.L.P., 

 Coah. and N. L.; also inland in Arg. and Parag. 



The young shoots emerging after fires are good forage but the older shoots 

 are much too tough even for horses. Formerly vast acreage of sacahuista were 

 therefore burned over purposely in the ranches of southern Texas; the practice 

 is less common now. 



2. Spartina altemiflora Lois. Smooth cordgrass. Fig. 125. 



Perennial from relatively soft deeply buried (and seldom collected) branched 

 rhizomes 4-7 mm. thick; aerial culms 6-15 dm. long, 3-14 mm. thick, erect, 

 unbranched, leafy; ligule 1-2 mm. long; blades 20-55 cm. long, 4-16 (-25) mm. 

 broad at the very base, flat, distally involute and wholly involute on drying; pan- 

 icle 1-4 dm. long, 7-22 mm. thick, tapered to both ends, somewhat spikelike but 

 lax; spikes 5 to 30 per panicle, 4—10 cm. long. 3-5 mm. thick, appressed or usually 

 diverging at angles of 10°-20°, closely overlapping; spikelets 10 to 40 per spike, 

 8-14 mm. long; first glume 4-10 mm. long; second glume as long as spikelet, the 

 lemma a little shorter; keels of glumes and lemma with some minute pubescence. 

 Incl. \ SIT. glabra (Muhl.) Fern. 



Abundant in colonies at the tidally-innundated shores of brackish to hypersaline 

 bays and river-mouths, along the Tex. coast, locally common, summer-fall; nat. to 

 the e. coast of N.A. from the Maritime Provinces to Tex., and also S.A. from 

 Qui. to Arg.; introd. in Wash., and in Fr. and Eng. 



3. Spartina cynosuroides (L.) Roth. Big cordgrass. Fig. 126. 



Perennial from deeply buried (rarely collected) rhizomes 7-15 mm. thick; 

 aerial culms 9-30 dm. long, 4-25 mm. thick, erect, unbranched, leafy; ligule 1-3 

 mm. long; blades 25-70 cm. long. 10-22 mm. broad at base, flat, at the tip in- 

 volute; panicle 15-30 cm. long, 4-7 cm. broad, more or less ellipsoidal; spikes 5 

 to 67 (usually 25 to 45) per panicle, 5-15 cm. long, 3-6 cm thick, basally shortly 

 naked, usually diverging at angles of 20°-30°, overlapping; spikelets 30 to 70 per 

 spike, 9-14 mm. long; first glume 3-7 mm. long; second gUime as long as spikelets, 

 the lemma a little shorter; glumes and lemmas minutely pubescent on the keels or 

 wholly glabrous. 



Locally abundant in colonies in muck at tidally submerged shores of brackish 

 bays and river-mouths, also in marshes, in s.e. Tex. (Chambers. Galveston and 

 Harris cos.), summer; coasts from Mass. to Tex. 



262 



