GRAMINEAE. VOL. I. 



2. Echinochloa colona (L.) Link. Jungle Rice. 

 Fig. 309. 



Panicum colonum L. Syst. Ed. 10, 870. 1759. 



Panicum Walteri Ell. Bot. S. C. & Ga. i: 115. 1817. Not 



Pursh, 1814. 

 Echinochloa colona Link, Hort. Berol. 2: 209. 1833. 



Culms tufted, smooth and glabrous, 6'-2i tall, often 

 decumbent and rooting at the lower nodes. Sheaths com- 

 pressed, usually crowded; blades flat, i'-j' long, i"-4" wide; 

 inflorescence composed of 3-18 i-sided more or less spreading 

 dense racemes, i'-i*' long, disposed along a 3-angled rachis 

 and generally somewhat exceeding the length of the inter- 

 nodes ; spikelets single, in pairs, or in 3's in 2 rows on one 

 side of the hispidulous triangular rachis, obovate, pointed, 

 the first scale about one-half as long as the spikelet, 3-nerved, 

 the second and third scales a little more than i" long, awn- 

 less, 5-nerved, hispid on the nerves, the fourth scale cuspidate. 



Fields and roadsides, Virginia to Kansas, south to Florida 

 and Texas. Common in all tropical countries. March-Sept. 



3. Echinochloa Walter! (Pursh) Nash. Salt- 

 marsh Cockspur-grass. Fig. 310. 



Panicum hirtellum Walt. Fl. Car. 72. 1788. Not All. 



1785- 



Panicum Walteri Pursh, Fl. Am. Sept. i : 66. 1814. 

 Panicum hispidum Muhl. Gram. 107. 1817. 

 Panicum Crus-galli var. hispidum Torr. Fl. N. Y. 2 : 



424. 1843. 

 Echinochloa Walteri. Nash, in Britton, Man. 78. 1901. 



Culms 3-6 tall, robust, smooth. Sheaths, at least 

 the lower ones, papillose-hispid; blades i or more 

 long, i'-i' wide, generally smooth beneath, strongly 

 scabrous above; panicle 6'-i8' long, consisting of 10-40 

 ascending or spreading branches ; spikelets ovate- 

 lanceolate, densely crowded in 2-4 rows on one side 

 of the scabrous and hispid rachis, brownish purple ; 

 second and third scales about li" long, scabrous 

 and hispid, tipped with upwardly barbed awns, 

 sometimes 10-20 times their length ; fourth scale 

 ovate-lanceolate, acuminate. 



In marshes and ditches along the coast, Ontario to 

 Rhode Island, Florida and Texas. Aug.-Oct. 



17. PANICUM L. Sp. PI. 55. 1753. 



Annuals or perennials of various habit, foliage and inflorescence. Spikelets i-2-flow- 

 ered, when 2-flowered the lower one staminate only. Scales 4, awnless, the 3 lower mem- 

 branous, empty, or the third with a staminate flower, varying in the same species; the inner 

 or fourth scale chartaceous, becoming indurated in fruit, the margins thick and inrolled, 

 shining, enclosing a palet of similar texture and a perfect flower. Stamens 3. Styles distinct. 

 Stigmas plumose. Grain free, enclosed in the hardened fruiting scale and palet. [Old Latin 

 name for some grass, probably millet, referring to its panicle, taken from Pliny.] 



About 500 species, in temperate and tropical regions. The old English name, Panic or Panic- 

 grass, is often applied to any of the species. Type species : Panicum miliaceum L. 

 Spikelets on one side of the rachis on short pedicels forming i -sided racemes. I. PASPALOIDEA. 

 Spikelets arranged in panicles, the divisions sometimes strict and narrow but not i -sided. 



' Basal leaf-blades long and narrow, similar to those of the stem; no rosulate tufts of leaves 



in the fall ; spikelets lanceolate to ovate, acute to acuminate, rarely obtuse. 

 Spikelets manifestly tuberculate. II. VERRUCOSA. 



Spikelets not tuberculate. 



Basal leaf-sheaths round or but little flattened, not keeled. 



Annuals. III. CAPILLARIA. 



Perennial by long rootstocks or stolons. 



Rootstocks and stolons naked or with a few large scales. IV. HALOPHILA. 



Rootstocks and stolons with numerous small broad scales. V. VIRGATA. 



Basal leaf-sheaths much compressed, broad, keeled, often equitant. VI. AGROSTOIDEA. 

 Basal leaf-blades unlike those of the culm, ovate to ovate-lanceolate ; perennial by rosulate 

 tufts which form in the fall at the base of the culms ; spikelets elliptic to spheric, usually 

 obtuse, rarely acute, never acuminate. VII. DICHOTOMA. 



I. PASPALOIDEA. 



Spikelets ovate, acute, about i*4" long; an aquatic grass. i. P. hemitomon. 



Spikelets oval or obovate, obtuse, about i l / 2 " long. 2. P. obtusum. 



