IX, C1 Merrill: Plants of Guam 55 
margins inflexed, thin, enwrapping the flowering glume, promi- 
nently ciliate-pilose. Flowering glume glabrous, smooth, shin- 
ning, narrowly lanceolate, acuminate, about 2.5 mm long, 0.6 mm 
wide, the palea as long as the glume but narrower. Caryopsis 
oblong, 1 to 1.2 mm long. 
R. C. McGregor 372, Cabras Island, October, 1911. 
A most peculiar species on account of the reduction of its empty glumes, 
although manifestly belonging in the genus Digitaria. The first and second 
glumes are entirely obsolete, while the third enwraps the flowering glume 
by its thin margins. Aside from its peculiar floral character, the species 
is well characterized by its slender, prostrate, branched stems, which root 
at the nodes, its ciliate-pilose pubescence, its small leaves, and its very 
short spikes. 
ISACHNE R. Brown 
ISACHNE MILIACEA Roth in Roem. & Schult. Syst. 2 (1817) 476. 
Panicum minutulum Gaudich. Bot. Freye. Voy. (1826) 410. 
Isachne minutula Kunth Rev. Gram. 2 (1829) ¢. 117; Safford 287. 
McGregor 404, wet places, hills back of Piti. 
Widely distributed, tropical Asia to Polynesia. The type of Gaudichaud’s 
species was from Guam, and McGregor’s specimen manifestly represents the 
same form. I can see no valid reason for considering it distinct from 
Isachne miliacea Roth, which is the older name. 
PANICUM Linnaeus 
PANICUM AMBIGUUM Trin. Mém. Acad. Petersb. VI 3’ (1835) 243. 
McGregor 488, G. E. S. 206. 
India to the Liu Kiu Islands southward to Malaya and Polynesia. 
PANICUM COLONUM Linn. Syst. ed. 10 (1759) 870. 
Echinochloa colona Link Hort. Berol. 2 (1833) 209; Safford 265. 
Thompson 13, McGregor 520, G. E. S. 146, 322, local name chaguan agaga. 
Warmer parts of both hemispheres. 
PANICUM DISTACHYUM Linn. Mant. 1 (1767) 183; Safford 345. 
G. E. S. 268. 
India to Malaya and Polynesia. 
PANICUM ISACHNE Roth Nov. Pl. Sp. (1821) 54. 
G. E. S. 126, in meadows. 
Mediterranean region to India. I am at loss to account for this species 
in Guam unless it be an accidentally introduced plant. It is quite the same 
as our Indian material representing Roth’s species. 
PANICUM LUZONIENSE Presl Rel. Haenk. 1 (1830) 308 ? 
G. E. S. 162. 
The specimen is larger than the Luzon form, nearly erect, unbranched, 
and with slightly larger spikelets. It seems to be a luxuriant form of 
P. luzoniense Pres}. 
Malay Peninsula and the Philippines. 
(In addition to the species above considered, there are in the collections 
