142 NORTH AMERICAN FLORA [VorumE 17 
TYPE LOCALITY: In loose gravelly soil in a deep cut in the mountains near Acapulco, Mexico.. 
DISTRIBUTION : Known only from the type locality. 
fl aaa re Bull. U. S. Dep. Agr. Agrost. 4: f. 7-3; Cire. U.S. Dep. Agr. Agrost. 15: 
Tribe 4. TRISTEGINEAE. Perennial grasses, with the racemes, the rachis 
of which is continuous, arranged in terminal dense or open panicles. Spike- 
lets articulated below the empty scales, solitary, in pairs, or fascicled, 1- or 2- 
flowered, the terminal flower perfect, with sometimes a second staminate flower 
below. Scales 3 or 4, the 2 or 3 lower usually empty, or rarely the upper one 
with a staminate flower, membranous, the first scale small, or occasionally 
aristiform and as long as or longer than the spikelet, the terminal scale of the 
spikelet bearing a perfect flower, awned or awnless, membranous, or sometimes. 
more delicate and hyaline ; palet hyaline or thinly membranous. 
Flowering scales awned. 38. ARUNDINELLA.. 
Flowering scales awnless. 
First scale about one half as long as the spikelet, ovate, with a blade. 39. TRISCENIA, 
First scale as long as or exceeding the spikelet, aristiform, bladeless. 40. ARTHROPOGON. 
38. ARUNDINELLA Raddi, Agrost. Bras. 36. 1823. 
Goldbachia Trin, Neue Entdeck, 2: 81. 1821. Not Goldbachia DC. 1821. 
Acratherum T,ink, Hort. Berol. 1: 230. 1827. , 
Calamochioé Reichenb. Consp. 52. 1828. 
Thysanachne Presl, Thysan. Nov. Pl. Gen. 1829. 
Brandtia Kunth, Rév. Gram. 511. 1831. 
Usually tall, sometimes low, grasses, with broad flat leaf-blades, and terminal open and 
lax or narrow and dense panicles. Spikelets articulated to the pedicel below the empty scales, 
in pairs, 1- or 2-flowered, the terminal flower perfect, the lower staminate or wanting. Scales. 
4; first scale shorter than the spikelet, awnless; second scale longer than the rest, acuminate, 
or sometimes produced into a straight awn; third scale shorter than the fourth scale, thinner, 
muticous, enclosing a hyaline palet and sometimes also a staminate flower; fourth scale mem- 
branous, hyaline or opaque, enclosing a perfect flower, entire or minutely toothed at the apex, 
and usually bearing a geniculate perfect (with a spiral column) or imperfect awn, rarely awnless. 
Stamens 3. Styles distinct from the base. Stigmas plumose. 
Type species, Arundinella brasiliensis Raddi. , 
Awn with the column shorter than the scale, rarely equaling it, tightly spiral 
and not reaching the apex of the second scale. 1. A. martinicensis. 
Awn with the column much longer than the scale, usually over twice its length, 
straight, somewhat twisted, rarely spiral, reaching the apex of the second 
scale or extending beyond it. 2. A. peruviana. 
1. Arundinella martinicensis Trin. Gram. Pan. 62. 1826. 
Thysanachne scoparia Presi, Thysan. Nov. Pl. Gen. 1829. 
Arundinella pallida Nees, Agrost. Bras, 465. 1829. 
Arundinella scopaxia Fourn. Mex. Pl. Gram. 55. 1881. 
Arundinella Palmeri Vasey; Beal, Grasses N. Am. 2: 76. 1896. 
Stems 1 m. tall or more; leaf-sheaths appressed-hispid toward the summit; blades up to 
4 dm. long and 2 cm. wide, rough, usually hispid on one or both surfaces; panicle usually 2-4 
dm. long, dense, its branches erect or nearly so, occasionally loose and open and sometimes 
larger with the branches bearing fewer spikelets and spreading or ascending; spikelets, exclusive 
of the awn, 3.5-4 mm. long, the first scale one half to two thirds as long as the second scale, 
3-nerved, the second scale 5-nerved, the third scale a little shorter or longer than the first, the 
fourth scale 1.5-2 mm. long, bearing an awn about twice its own length, the tightly spiral 
column shorter than the scale or rarely equaling it, and shorter than the subula. 
TYPE LOCALITY: Martinique. 
DISTRIBUTION : Southern Mexico to Costa Rica, and in the West Indies. 
ILLUSTRATIONS: Presl, Symb. f/. 6; Beal, Grasses N. Am. 2: f. 20, A, a. 
