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..
J uncus Gerardi Lois. Journ. de Bot. 2: 284. 1809.
Tufted, 8-28' high, with creeping rootstocks. Basal leaves with rather loosely clasping auriculate sheaths, the long blades flat, or when dry involute; 1 or 2 cauline leaves usually present, similar to the basal; inflorescence sometimes exceeded by its lowest bract; panicle erect, strict or slightly spreading; perianth 1"-1 1/4" long, its parts oblong, obtuse, with green midrib and broad dark brown margins, straw-colored in age; stamens 6, barely exceeded by the perianth; anthers much longer than the filaments; capsule one-fourth to one-half longer than the perianth, obovoid, mucronate, dark brown, shining, 3-celled; seed dark brown, obovate, acute at base, obtuse and often depressed at the summit, marked by 12-16 conspicuous ribs, the intervening spaces cross-lined.
On salt meadows, Gulf of St. Lawrence to Florida; rare .inland to western New York and the vicinity of the Great Lakes. Occurs also on the northwest coast, and in Europe.
Plants 1°-4° high, pale green. Leaves basal; blades about half the length of the scapes or less, very narrowly linear but flat, frequently somewhat involute; scapes tufted, often relatively stout but wiry, striate-grooved: inflorescence 1'-2' high, or rarely slightly larger, usually rather congested, considerably exceeded by its bract, few-flowered; perianth green or pale straw-colored, 2"-2 1/2" long, its parts firm, nearly equal, lanceolate-subulate, acute, more or less spreading, scarious-margined; stamens about half as long as the perianth; anthers slightly shorter than the filaments; capsules ovoid-oval, 3/4-7/8 the length of the perianth, somewhat apiculate: seed oblong, 1/2"-1/4" long, apiculate at each end.
In damp soil and open places, Quebec and Maine to Ontario, Saskatchewan, British Columbia, Washington. Virginia, Tennessee and Mexico.
Juncus tenuis Willd. Sp. PI. 2: 214. 1799. Juncus monostichus Bartlett, Rhodora 7: 50. 1905. (?)J. dichotomies platyphyllus Wiegand, Bull. Torr. Club 30: 448. 1903.
Tufted, 2'-30' high; basal leaves with blades 1/4"-3/4" wide, sometimes involute in drying, about half the height of the stem; the sheaths usually with broad scarious margins; inflorescence usually much exceeded by its lowest leaf, 4' high or less, the flowers rarely secund; perianth I 3/4 -2 1/2" long, its parts lanceolate, acuminate, exceeding the capsule, widely divergent, touching the capsule for about half their length; stamens 6, about half as long as the perianth; anthers shorter than the filaments; capsule oblong to obovoid, rounded at the top, imperfectly 3-celled; seed 1/5"-1/4" long, narrowly oblong to obovoid, with oblique ends, reticulated in about 16 rows, the areolae two or three times broader than long.