468 
7. BE. ovata Rk. & S. Stems nearly terete, 20 tu 35 em. high: spike globose-ovoid 
to ovate-oblong, obtuse, 2 to 12 mm. long, dull brown: scales very obtuse, densely 
crowded in many ranks: style sometimes 3-cleft: achene obovate with narrow base, 
pale brownish, shining, shorter than the 6 to 8 bristles, broader than the short- 
deltoid acute flattened tubercle. (£. obtusa Schult.)—Valley of the lower Rio Grande ; 
a species oceurring on both sides of the continent. Var. ENGELMANNI Britton (EF. 
Engelmanni Steud.), of almost equally extensive range, has an elongated spike 
tapering to a blunt point. 
8. EB. palustris R. & 8. Perennials, with running rootstocks and nearly terete 
striate stems (3 to 15 dm. high): spike oblong-lanceolate, pointed, many-flowered: 
scales ovate-oblong, loosely imbricated, reddish-brown with a broad and translucent. 
whitish margin and a greenish keel, the upper acutish, the lowest rounded and 
often enlarged: stamens 2 or 3: style sometimes 3-cleft: achene narrowly obovate, 
somewhat shining, crowned with a short ovate or ovate-triangular flattened tuber- 
cle, shorter than the usually 4 bristles.—In the valley of the lower Rio Grande, and 
probably common throughout eastern and southern Texas, as it is one of the com- 
ionest of species. When in water it is rather stout and tall; in wet grassy grounds 
it is slender and lower. Var, GLAUCESCENS Gray, which occurs with the type, has 
slender or filiform stems, and narrower acute beak-like tubercle sometimes half as 
long as the achene. From the lower Rio Grande is also reported a form (. calva 
Torr.) of this variety with no bristles. 
** * Style 3-cleft: achene triangular, 
9, HB. acicularis R. & 8. Stems finely capillary (5 to 20 cm. long), more or less 
d-angular: spike 3 to 9-flowered: scales thin, ovate-oblong, rather obtuse, greenish 
with purple sides: achene obovate-oblong, with 8-ribbed angles and 2 or 3 times as 
many smaller intermediate ribs, longer than the 3 or 4 very fugacious bristles ; 
tubercle conical-triangular, contracted at its junction with the achene.—Through- 
out North America, and extending into Mexico, 
10. B, tortilis Schultes. Stems sharply triangular, filiform, twisting when dry, 
3 to 4.5 dm. high: spike ovate, 4 to6 mm. long, somewhat acute, few-flowered: 
scales somewhat coriaceous, ovate, obtuse, whitish (with light chestnut sides): 
bristles 6, very rigid, a little overtopping the achene, which is longitudinally fur- 
rowed (the furrows strongly pitted); tubercle conical, compressed, produced into a 
beak nearly one-third as long as the achene. (EZ. simplex Torr.)—From the south 
Atlantic and Gulf States to Texas. 
ll. BE. tuberculosa R. & 8. Like the last, but stems flattish, spike 6 to 12 mm. 
long and many-flowered, and tubercle flattish-cap-shaped and as large as the body 
of the achene.—Extending from the north Atlantic States to the Gulf States and 
westward to Texas. 
12, BE. microcarpa Torr. Stems capillary, quadrangular, 15 to 20em. high: spikes 
oblong, compressed (often proliferous), 10 to 20-flowered: seales broadly ovate, 
somewhat acuminate, somewhat keeled, with whitish margins and brownish-red 
sides, the lowest one much the largest: bristles 3 to 5, very slender and fragile, 
shorter than the achene, which is minute, obovate, obtusely triangular, and 
smooth: tubercle triangular, very minute, closely sessile—Extending through the 
south Atlantie and Gulf States into Texas, 
13. B. albida Torr. Stems capillary, terete: spike dense, ellipsoidal or oblong, 2 
to 8 mm. long, acutish, 20 to 30-flowered, with pale ovate mostly obtuse coriaceous 
scales: achene very small, obovate, very smooth, with a broadly triangular tubercle 
upon a narrow base, shorter than or excecding the reddish bristles. —Salt marshes, 
from the south Atlantic and Gulf States to the valley of the lower Rio Grande. 
Var. BERLANDIERI Clarke, of southeastern Texas, is stouter, with longer heads, 
and the tubercle slightly more beaked. 
ld. B, tenuis Schultes, Stems almost capillary, ereet from running rootstocks, 
4-angular and flattish (3 dm. high), the sides concave: spike elliptical, acutish, 20 
