HITCHCOCK AND CHASE — NORTH AMERICAN GRASSES. 11 



DESCRIPTION. 



Culms tall, glabrous ; sheaths densely villous or glabrate ; ligule a very short, 

 densely ciliate membrane; blades (only the upper seen) gradually narrowed 

 from the cordate base to a slender point, 8 to 18 cm. long, as much as 2.5 cm. 

 wide near base, pubescent on both surfaces; panicle 30 cm. long, about 8 cm. 

 wide, rather densely flowered, the branches ascending, clustered, the longer 

 ones as much as 10 cm. long, spikelet-bearing from base; spikelets single or 

 in clusters along the scabrous rachis, 4 to 4.5 mm. long, the pedicels 1 to 2 

 mm. long, densely scabrous-hispidulous ; first glume about as long as the spike- 

 let, 3-nerved, pointed, scabrous, villous along the margins and at the apex; 

 second glume about as long as the fruit, 5-nerved, scabrous, the long hairs 

 sparse or wanting; sterile lemma similar to the second glume but weakly 

 5-nerved, the palea well developed, ciliate on the keels; fertile lemma about 

 3 mm. long, the boat-shaped point distinct, the appendages rather firm, ovate- 

 oblong, distinct from near the base, about 0.5 mm. long. 



DISTRIBUTION. 



Known only from the type collection. 

 Oaxaca: Trapiche de la Concepci6n, Lieomann 457. 



Explanation of Plate 8. — Ichnanthus mewicanus. Type specimen. Natural size. 



10. Ichnanthus ichnodes (Griseb.) Hitchc. & Chase. 



Panicum ichnodes Griseb. Fl. Brit. W. Ind. 551. 1864. Collected in Trinidad 

 by Crueger near Port of Spain, " heights of S. Anne." The type specimen in 

 the Grisebach Herbarium consists of an incomplete leafy culm and a large 

 spreading panicle. 



Ichnanthus ichnodes Hitchc. & Chase, Contr. U. S. Nat. Herb. 18: 335, 1917. 

 Based on Panicum ichnodes Griseb. 



DESCRIPTION. 



Plants erect from a somewhat decumbent base, bearing short knotty root- 

 stocks and forming colonies; culms 1 to 2 meters tall, glabrous, or sparingly 

 villous below; sheaths keeled, the lower overlapping, glabrous or sparsely 

 villous, densely villous on the margin and on the collar; ligule a ciliate mem- 

 brane about 1 mm. long; blades narrowly lanceolate to linear, the lower ones 

 as much as 30 cm. long, 1 to 2 cm. wide, narrowed below, scabrous, sometimes 

 sparsely villous, densely villous above near base; panicle oblong, as much 

 as 30 cm. long, the branches fascicled or branched at base, finally spreading, 

 pubescent or villous at base; spikelets blunt, about 2.5 mm. long; first glume 

 very scabrous on the keel, more than half as long as spikelet, often sparsely 

 villous ; second glume roughened toward apex ; sterile floret often staminate ; 

 fruit 2 mm. long, the appendages 0.5 mm. long. 



The elongate blades and the large, much-branched, many-flowered panicles 

 of blunt spikelets give this species the aspect of a species of Panicum. The 

 small spikelets lack the point at the ends of the glumes and lemmas, but the 

 appendages at the base of the fertile lemma show that the species belongs to 

 Ichnanthus. 



