RUSH FAMILY. 395 
Juncus Canadensis subcaudatus Engelm. Trans. St. Louis Acad. 2: 474. 1868. 
Stems 15'-30' high, slender, frequently weak and reclining; heads few, scattered; seed with 
very short tails. Rhode Island to Pennsylvania and Georgia. 
Juncus Canadensis brevicaudatus Engelm. Trans. St. Louis Acad. 2: 436. 1866. 
Juncus Canadensis var. coarctatus Engelm. Trans. St. Louis Acad. 2: 474. 1868. 
Stems erect, 8’—-30' tall, slender, closely tufted; panicle contracted; heads 2-6-flowered; seed 
2''-3" in length, long-tailed. Nova Scotia to Minnesota and New Jersey. 
38. Juncus acuminatus Michx. Sharp-fruited Rush. (Fig. 956.) 
Juncus acuminatus Michx. Fl. Bor. Am. 1: 192. 
1803. 
Plant 10’-3° high; rootstock short and incon- 
spicuous. Stems few or several in a tuft, erect, 
1-3-leaved; blades of the lower leaves 4’-S’ long, 
4//-1’’ thick, the upper shorter; inflorescence 
2/-6/ high, and with 5-50 heads, rarely larger, 
or reduced even to a single head, its branches 
usually spreading; heads top-shaped, hemi- 
spheric or subspheric, 3-20-flowered; perianth 
14%//-134’’ long, its parts lanceolate-subulate, 
nearly equal; stamens 3, about one-half as long 
as the perianth; anthers shorter than the fila- 
ments; capsule ovate-lanceolate, broadly acute, 
mucronate, 1-celled, equalling the perianth, 
light brown at maturity, the valves separating 
- through the apex; seed oblong, about \%/’ in 
length, tipped at either end, reticulate in 16-20 
longitudinal rows, the areolae transversely 
many-lined. 
Maine to southern Ontario and Minnesota, south 
to Georgia and Mexico. Also on the northwest 
coast. Heads often proliferous. 
Juncus acuminatus deébilis (A. Gray) Engelm. Trans. St. Louis Acad. 2: 463. 1868. 
Juncus debilis A. Gray, Man. 506. 1848. 
Smaller, densely tufted, 1o'-20' high, the stems often weak and procumbent; perianth shorter, 
1’/-14"' long; capsule linear-oblong, obtuse, about one-third longer than the perianth, short-tipped. 
New Jersey to South Carolina. 
39. Juncus robustus (Engelm.) Coville. Stout Rush. (Fig. 957.) 
Juncus acuminatus var. robustus Engelm, Trans. 
St. Louis Acad. 2: 463. 1868. 
Plant about 3° high. Stems single or few in 
a tuft, stout, nearly terete, commonly 114//-2/’ 
thick below, 1-2-leaved; blades erect, terete, con- 
spicuously many-septate, 8’-2° long, 1/’-134// 
thick, usually reaching or exceeding the inflores- 
cence; inflorescence 4’-10’ high, with moderately 
spreading branches and innumerable (com- 
monly 300-500) heads, the blade of its lowest leaf 
sometimes half as long as the inflorescence; heads 
2-10-flowered; perianth 1//-14’/ long, its parts 
nearly equal, lanceolate-subulate; stamens 3,one- 
half to two-thirds as long as the perianth; capsule 
equalling or one-third exceeding the perianth, 
straw-colored at maturity, narrowly to broadly 
oblong, obtuse with a short tip, 3-sided when 
dry, 1-celled, the valves separate and involute 
after dehiscence; seed nearly asin /. acumminatus. 
Southern Illinois to southeastern Kansas, Okla- 
homa, Louisiana and Texas. 
