BOTANY OF THE MAYA AREA


 54. TRACHYPOGON Nees
Spikelets rather distant, the conspicuous white callus hairs contrasting
 with the usually dark purple glumes; awns short-hispid; ligule
 mostly 3 to 10 mm. long ..-. ...... .. .... ........ -....... T. montufari
Spikelets crowded, pale, the callus hairs inconspicuous; awns dis-
 tinctly plumose; ligule not more than 1.5 mm. long _-.......... 2. T. angustifolius

1. Trachypogon montufari (H.BIC.) Nees, Agrost. Bras. 342. 1829.
 Perennial; clums tufted, erect, 30 cm. to more than 1 m. tall; nodes ap-
pressed-hispid; blades flat or subinvolute, attenuate-pointed, 8 to 30 cm.
long, not more than 5 mm. wide (usually less); racemes solitary (rarely
paired), 8 to 15 cm. long; spikelets about 1 cm. long; glumes pubescent,
dark purple; awns 3 to 5 cm. long, twice geniculate, appressed-hispid, the
hairs short. Dry rocky hills and waste places, Mexico to Ecuador.
 BRITISH HONDURAS. El Cayo District: Mountain Pine Ridge, Bartlett
11785.

2. Trachypogon angustifolius (H.B.K.) Nees; Hack. DC. Monog. Phan. VI: 326. 1889.
 Pajon.
 Perennial; culms slender, erect, 40 to 80 cm. tall; sheaths glabrous or the
lower ones sparsely pilose; blades 5 to 20 cm. long (usually about 10 cm.),
1 to 3 mm. wide; ligule not more than 1.5 mm. long; racemes solitary (or
rarely paired), 8 to 12 cm. long; fertile spikelets 8 mm. long; glumes pale,
pubescent below, glabrous or nearly so above; awns 3 to 4.5 cm. long,
plumose to the second bend, sometimes throughout. Sandy prairies and
rocky hills, Mexico to Colombia; also in Bolivia and Uruguay.
 One of the dominant grasses of open well-drained grasslands of central
Petdn.
 BRITISH HONDURAS. El Cayo District: Mountain Pine Ridge, Bartlett
11746. 11747. Belize District: Manatee Lagoon, Peck 139. Gracie Rock,
Gentle 1646.
 GUATEMALA. Petin: La Libertad, Lundell 2306, 2392, 2467. Sabana
Zotz, Lundell 3595.

 55. ISCHIEMUM L.
1. Ischaemmum latifolium (Spreng.) Kunth, R6v. Gram. 1: 168. 1829.
 Annual; culms freely branching, decumbent, widely spreading, or sub-
erect, rooting at the lower nodes, as much as 3 m. long; blades 10 to 20 cm.
long, 1 toe3 cm. wide, acuminate, narrowed toward the base, the margins
scabrous; racemes 4 to 8 cm. long, few to several, aggregate on the short
axis. Brushy slopes, pine woods, and open banks, Mexico and the West
Indies to Ecuador and Brazil.
 BaITISH HoNDURas. Belize District: Sibun River, Bartlett 11398, Gentle
1442. Manatee Lagoon, Peck 254; Smart 61. El Cayo District: Mountain
Pine Ridge, Bartlett 11843. Stann Creek District: New Town, Schipp 897.

 56. HACKELOCHLOA Kuntze
1. Hackelochloa granularis (L.) Kuntze, Rev. Gen. PI. 2: 776. 1891.
 Annual; culms slender, freely branching; sheaths conspicuously hispid;
blades flat, mostly 5 to 10 cm. long, 5 to 10 mm. wide; racemes solitary,
numerous, short, single from each bract; rachis joint and sterile pedicel