76 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 
having acuminate lemmas. These four species and 7’. mutica (Torr.) 
Scribn. agree in having woolly lemmas, the lower part of the three 
nerves being long-villous, and in having paleas villous on the wings. 
Triodia mutica has a somewhat elongate panicle and differs in having 
very obtuse, broad, sometimes minutely notched, awnless lemmas, the 
lateral nerves disappearing before reaching the margin. The afore- 
mentioned species might be set off under Erioneuron, but they would 
not form a coherent group. 
Triodia flava (u.) Hitche. (Poa flava L.) (fig. 85) has an open, 
elegantly drooping panicle of purple spikelets, the nerves of the 
lemmas pubescent below, extending into 3 mucros. This is common 
in autumn through the Eastern States in meadows and open wood- 
land and is sometimes called purple-top. It exudes a sticky sub- 
stance on the culm below the panicle and on the main branches of 
the inflorescence, to which dirt adheres. One species, 7. drwm- 
mondit Scribn. and Kearney, produces rhizomes. 
Three species (besides 7’. mutica mentioned above) have a spike- 
like panicle. These are 7. albescens Vasey, with glabrous lemmas; 
T. elongata (Buckl.) Scribn., with glumes nearly as long as the 
spikelet; and 7’. stricta (Nutt.) Vasey, with shorter glumes but mu- 
cronate lemmas. The other species have more or less open panicles. 
In general the species of Triodia are of little importance agricul- 
turally. Triodia pulchella is often abundant on the ranges, but is 
not relished by stock, the little dry plants being seldom eaten. 
27. TRIPLASIS Beauv. 
Spikelets few-flowered, the florets remote, the rachilla slender, 
terete, disarticulating above the glumes and between the florets; 
glumes nearly equal, smooth, 1-nerved, acute; lemmas narrow, 
3-nerved, 2-lobed, the nerves parallel, pubescent or villous, the lateral 
pair near the margin, the midnerve excurrent as an awn, as long as 
or longer than the lobes; palea shorter than the lemma, 2-keeled, the 
keels densely Jong-ciliate on the upper half. 
Slender tufted annuals or perennials, with short blades, short, open, 
few-flowered purple panicles terminating the culms, and cleistoga- 
mous narrow panicles in the axils of the leaves. Species three; south- 
eastern United States. 
Type species: Triplasis americana Beauv. 
Triplasis Beauv., Ess. Agrost. 81, pl. 16, f. 10. 1812. The single species, 
T. americana, is figured. 
Uralepis Nutt., Gen. Pl. 62. 1818. Nuttall describes two species, U. purpurea, 
based on Aira purpurea Walt. (Triplasis purpurea (Walt.) Chapm.) and U. 
aristulata, which is the same species. The first is selected as the type. The 
name is spelled Uralepsis, but this is a typographical error. Nuttall states 
that it is based on the Greek words oura and lepis. 
Diplocea Raf., Amer. Journ. Sci. 1: 252. 1819. One species described, D. bar- 
bata, which is the same as Triplasis purpurea. 
Merisachne Steud., Syn. Pl. Glum. 1: 117. 1854. Contains one species, 
M. drummondu Steud., Drummond 330, from Texas (Triplasis purpurea). 
