This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Plants 8'-16' high or sometimes with longer weak procumbent stems, often densely tufted. Leaves with blades usually less than half the length of the plant, more or less flattened in age or in drying; panicle with ascending or diffuse branches; heads mostly 2-6-flowered; perianth about 1" long, its parts narrowly lanceolate the inner broader at the base and less concave; stamens much over half as long as the perianth; capsules linear-lanceolate in outline, about one-third exceeding the perianth.
In wet places and sandy shores, Rhode Island to Missouri, Florida, Mississippi and Arkansas.
Juncus acuminatum var. robustus Engelm. Trans. St.
1: 395. 1896. Not S. Wats.
Plant about 3° high. Stems stout, commonly 1V-2" thick below, 1-2-leaved; blades erect, terete, conspicuously many-septate, 8'-2a long, 1"-1 3/4" thick, usually reaching or exceeding the inflorescence; inflorescence 4'-10' high, with innumerable (commonly 300-500) heads, the blade of its lowest leaf sometimes half as long as the inflorescence; heads 2-10-flowered; perianth 1"-ii" 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 as in J. acuminatum.
Southern Illinois to southeastern Kansas, Oklahoma, Louisiana and Texas.
Plant 1 -2 high. Stems few in a tuft, from a short-branched inconspicuous rootstock, erect, slender, terete or slightly compressed, 2-4-leaved; blades 4'-8' long, \"-\" thick; inflorescence diffusely branched, widely spreading, 4'-8' high and broad, its lowest bract with a blade either obsolete or sometimes nearly as long as the panicle; heads 3-12-flow-ered; perianth 1 1/4"-1 3/4" long, its parts subulate, equal; stamens half to two-thirds as long as the perianth; anthers shorter than the filaments; capsule narrowly linear-lanceolate in outline, 2"-2 3/4" long, acute to obtuse at the apex, with a short tip, 3-sided, light brown, 1-celled; seed oblong to obo-void, 1/5"- 1/4" long, acute at the base, abruptly tipped, reticulate in about 16 rows, finely cross-lined.
Indiana to Kansas, Georgia and Texas.