JUNCACEAE 261 
32. Juncus robüstus (Engelm.) Coville. Plants 6-10 dm. high. Rootstock short, 
inconspicuous : stems few in a tuft, nearly terete, 2-3 mm. thick below, 1-2-leaved : 
leaf-blades erect, terete, conspicuously septate, 20-60 cm. long, 2-3.5 mm. thick, usually 
reaching the inflorescence: inflorescence 10-25 cm. high, with moderately spreading 
branches and many (300-500) heads, its largest bract with the blade obsolete or sometimes 4 
as long as the inflorescence : heads 2-10-flowered : perianth 2-3 em. long: sepals and petals 
nearly equal, lanceolate-subulate: stamens j-3 as long as the perianth: capsule 1-14 
times as long as the perianth, light brown or almost stramineous at maturity, narrowly to 
broadly oblong, obtuse but short apiculate, 3-angled when dry, 1-celled, the valves sepa- 
rate and involute after dehiscence: seeds as in J. acuminatus. 
In low grounds, Illinois to Kansas, Louisiana and Texas. Summer. 
33. Juncus Hllióttii Chapm. Plants 2-8 dm. high. Stems tufted, from branched 
congested rootstocks, 3-leaved, nearly terete : lower leaf-blades commonly 8-15 cm. long, 
or rarely reaching 25 em. high, or occasionally somewhat larger, with moderately spreading 
branches, and 5 or sometimes 50 heads, the blade of the lowest involucral bract usually ob- 
solete, or rarely 4 cm. long: heads 2-5-flowered : perianth 2-2.5 mm. long: sepals and 
petals equal, lanceolate and acute: stamens 3-1 as long as the perianth ; anthers shorter 
than the filaments : capsule oblong to narrowly oblong, chestnut-brown above and shin- 
ing, broadly acute, equalling the perianth, 1-celled, the valves spreading and often invo- 
lute when mature: seeds lanceolate-oblong, 0.35-0.45 in length, reticulated in about 
12-14 rows, the areolae linear-oblong, and smooth, or marked with a single longitudinal 
line. 
In bogs or ditches, North Carolina to Florida and Texas. A large form, J. Elliottii polydnthemus C. 
Mohr, has stems 6-8 dm. tall, flat long-acuminate leaves 25-35 cm. long, and panicles with very num- 
erous (100-200) 4-6-flowered heads; it occurs in southern Alabama. Summer and fall. 
34. Juncus acuminàtus Michx. Plants 2-8 dm. high. Rootstock short and in- 
conspicuous : stems few or several in a tuft, terete or slightly compressed, 1-3-leaved : 
blades of the lower leaves 10-18 cm. long, 1-2 mm. thick, the upper shorter : inflorescence 
c mmonly 5-15 em. high, and with 5-50 heads, rarely larger, or reduced to a single head, 
its branches usually spreading or sometimes strict : heads 3-20-flowered, commonly 5-12- 
flowered: perianth 2.5-3.5 mm. long: sepals and petals lanceolate-subulate, nearly 
equal: stamens about 4 as long as the perianth : capsules ovoid-lanceolate, broadly acute, 
mucronate, 1-celled, equalling the perianth, light brown, the valves separating through 
the apex in dehiscence : seeds narrowly to broadly oblong, 0.4-0.55 mm. in length, acute 
at both ends, reticulated in about 16-20 longitudinal rows, the areolae transversely plu- 
rilineolate. 
In low grounds, Maine to Ontario, Minnesota, Georgia, Texas and Mexico. Also on our north- 
western coast. Spring. 
35. Juncus débilis A. Gray. Plants 2-4 dm. high or sometimes with weak procum- 
bent stems, often densely tufted. Leaves with blades usually less than 3 the height of the 
plant, more or less involute in age or in drying: paniele with ascending or diffuse 
branches: heads mostly 2-6-flowered : perianth 2-2.5 mm. long : sepals and petals nar- 
rowly lanceolate, the petals broader at the base and less concave : stamens much over 3 as 
long as the perianth: capsules linear-lanceolate in outline, about 4 exceeding the 
perianth. 
. In wet places and sandy shores, New Jersey to Missouri, Florida, Mississippi and Arkansas. 
Spring and summer. 
2. JUNCOIDES Adans. 
Perennial caulescent herbs, with glabrous or sparingly webby-pubescent foliage. 
Leaves with closed sheaths and grass-like blades. Inflorescence various, often congested. 
Flowers always subtended by bractlets, these usually lacerate or denticulate. Stamens 6 
(in our species). Ovary 1-celled. Ovules 3, basal. Capsule sessile, 1-celled. Seeds 3, 
reticulated, sometimes carunculate but not distinctly tailed. [Luzula DC.] Woonp-RUSH. 
Peduncles terminated by 1 or rarely 2 flowers: capsule of an ovoid type. 1. J. pilosum. 
Peduncles terminated by compact spikes: capsule of an obovoid type. : 
Sepals and petals 3-4 mm, long: capsule much surpassed by the perianth. 2. J. echinatum. 
Sepals and petals 2-2.5 mm. long: capsule surpassing the perianth or about equal- 
ling it in length. 3. J. bulbosum. 
1. Juncoides pildsum (L.) Kuntze. Stems 1-3 dm. tall, 2-4-leaved : leaf-blades 
flat, 3-8 mm. wide, webby, especially when young, blunt and almost gland-like at the 
tip: inflorescence umbel-like, subtended by a bract 10-25 mm. long: peduncles filiform, 
equal or nearly so, 1-flowered or rarely 2-flowered : perianth 2.5-3 mm. long: sepals and 
petals triangular-ovate, brown except the hyaline margins, about twice as long as the 
