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..
Juncus articulatus L. Sp. PI. 327. 1753.
Rootstock branching; stems erect or ascending, 8'-2° high, tufted, somewhat compressed, 2-4-leaved; basal blade-bearing leaves only 1 or 2, usually dying early; stem leaves with rather loose sheaths and conspicuously septate blades; inflorescence rarely exceeding 4' in height, its branches spreading; heads hemispheric to top-shaped, 6-12-flowered; perianth i"-i 1/2" long, the parts nearly equal, lanceolate, acuminate, reddish brown with a green midrib or green throughout; stamens 6, one-half to three-fourths as long as the perianth; anthers shorter than the filaments; capsule longer than the perianth, brown, 3-angled, sharply acute, tapering into a conspicuous tip, 1-celled; seed oblong-obovoid, about \" long, reticulate in about 16-20 rows, the areolae finely cross-lined.
Labrador to Massachusetts, New York, Michigan and British Columbia. Also in Europe and Asia. On ballast ground about Philadelphia and Camden a form occurs with obtuse perianth-parts and broadly acute capsules, apparently introduced.
Stems erect, 6'-2o' high in loose tufts, from creeping rootstocks, 1-2-leaved; stem leaf or leaves usually borne below the middle; panicle 2i'-8' high, sparse, its branches strict or slightly spreading; heads 3-12-flow-ered; perianth 1"-1 1/4" long, the inner parts shorter than the outer, obtuse, usually purplish toward the apex, the three outer paler, obtuse, mucronate or acute; stamens 6, half to two-thirds as long as the perianth; anthers much shorter than the filaments; capsule ovoid-oblong, slightly exceeding the perianth, straw-color or brown, broadly acute or obtuse, with a short tip; seed about \" in length, narrowly obovoid to oblong, apicu-late, acute or acuminate at the base, lightly reticulate in about 20 rows, the areolae finely cross-lined.
Greenland to British Columbia, south to Pennsylvania, Nebraska and Washington.
Juncus nodosus L. Sp. PI. Ed. 2, 466. 1762.
Stems 6'-2° high, erect, arising singly from tuberlike thickenings of a slender, nearly scaleless rootstock; stem leaves 2-4, and like the basal ones with long erect blades, the upper overtopping the inflorescence; panicle shorter than its lowest bract, seldom exceeding 2i', bearing 1-30 heads; heads spherical, several-many-flowered, 3 1/2"-6" in diameter; perianth 1 2/5"-1 3/4" long, its parts lanceolate-subulate, usually reddish brown above, the inner longer than the outer; stamens 6, about one-half as long as the perianth; anthers equalling the filaments; capsule lanceolate-subulate, 3-sided, 1-celled, exceeding the perianth; seed oblong, acute below, apiculate above, rarely more than 1/5" long, reticulate in 20-30 rows, the areolae finely cross-lined.
Nova Scotia to Virginia, Nebraska and British Columbia Also in Nevada.