260 CYPERACEAE, 
3. Fimbristylis laxa Vahl. Weak Fimbristylis. (Fig. 606.) 
4: Fimbristylis Vahlii (Lam. ) 
Scirpus Vahlii Lam. Tabl. Encycl. 1: 139. 
Fimbristylis Vahlii Vink, Hort. Berol. 
1827 
Fi imbrist} vlis congesta Torr. Ann. Lye. N. Y. 
1836. 
Annual, culms very slender, densely 
Fimbristylis laa Vahl, Enum. 2: 292. 1806. 
Fimbrishylis Baldwiniana ‘Torr. Ann. Liye. I. Wty33 
344. 1836. 
Annual, roots fibrous, culms slender, flattened, 
striate, densely tufted, erect or ascending, 2’—15’ 
long, usually longer than the leaves. Leaves flat, 
about 4’ wide, glabrous or sparingly ciliate, pale 
green and appearing glaucous, those of the involu- 
cre 3-5, one of them often exceeding the umbel; 
umbel simple or slightly compound, the central 
spikelet sessile; spikelets ovoid or ovoid-oblong, 
3//-6’’ long, about 1’’ in diameter; scales ovate, thin, 
pale greenish-brown, subacute or mucronulate; sta- 
men I; style 2-cleft, pubescent; achene biconvex, 
obovoid, light brown, longitudinally ribbed, the ribs 
tubercled and connected by very fine cross-lines. 
In moist soil, southern Pennsylvania to Florida, 
west to Illinois, Missouri and Texas. Also in tropical 
America. July-Sept. 
Link. Vahl’s Fimbristylis. (Fig. 607.) 
1791. 
I: 287. 
3: 345: 
tufted, 
compressed, striate, erect or ascending, 1/—4’ 
high, longer than or equalling the leaves. 
Tyeaves setaceous or almost filiform, rough, 
those of the involucre 3-5, erect, much exceed- 
ing the simple capitate cluster of 3-8 spikelets; 
spikelets oblong-cylindric, obtuse, 2’’-4’’ long, 
about 4’ thick, many-flowered; scales lanceo- 
late, pale greenish-brown, acuminate; stamen 
1; style 2-cleft, glabrous below; achene minute, 
biconvex, yellowish-white, cancellate by longi- 
tudinal and transverse ridges. 
In moist soil, Missouri to ‘Texas, east to North 
Carolina and Florida. Also in ballast about the 
eastern seaports. July—Oct. 
Be eee eaumaels (L.) R.&S. Slender Finibristy’ lis. (Fig. 608.) 
Scirpus autumnalis 1. Mant. 2: 180. 1771. 
Fimbrisiylis autumnalis R. & S. Syst. 2:97. 1817. 
Annual, roots fibrous, culms very slender, densely 
tufted, flat, roughish on the edges or smooth, erect, 
ascending or spreading, 3-15’ long, usually much 
exceeding the leaves. Leaves narrowly linear, flat, 
%4//-1/’ wide, long-acuminate, glabrous, those of 
the involucre 2-3, usually all shorter than the um- 
bel; umbel compound or decompound, the primary 
rays ’-114’ long, the secondary filiform; spike- 
lets linear-oblong, acute, 2’/-5’’ long, 14’ thick 
or less, several-many flowered; scales ovate-lanceo- 
late, subacute, strongly mucronate, greenish-brown, 
the midvein prominent; stamens 1-3; style 3-cleft; 
achene obovoid, nearly white, 3-angled with a ridge 
on each angle, very finely reticulated and some- 
times roughened. 
In moist soil, Maine to Michigan, south to Florida 
and Louisiana. Also in tropical America. June-Sept. 
