This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", 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..
E. paniculatum Nutt.; T. & G. Fl. N. A. 1: 490. 1840.
Annual, slender, 1°-2° tall, loosely branched, glabrous below, glandular-pubescent above, the stem terete. Leaves alternate, varying from linear to linear-lanceolate, 1' - 3' long, acute, denticulate or nearly entire, attenuate into slender winged petioles, often involutely folded; pedicels subtended by narrow bracts or bearing these some distance from their bases; calyx often purple, its tube funnelform, 1"-ii" long, shorter than the lanceolate segments; petals cuneate, notched, 3"-4" long, violet; capsules ascending, linear-fusiform, 10"-15" long, curved; seeds obovoid, 1" long, black, slightly papillose.
Lake Huron (according to Macoun); South Dakota to Alberta, to British Columbia, Colorado, Arizona and California. Summer.
Erect, much branched, bushy, 1°-3° high, more or less canescent above, with incurved hairs-often arranged in lines, glabrate below. Stem and leaves often purplish; leaves generally slender-petioled but sometimes sessile, narrowly lanceolate, acute or acuminate at the apex, narrowed at the base, sharply serrulate or denticulate, 2'-6' long, 3"-8" wide; flowers numerous in the axils, pink or white, 2"-3" broad, generally nodding; stigma entire or merely notched; capsules short-peduncled, finely pubescent, 1'-2' long, about 1" thick; seeds obconic-fusiform, beakless, papillose, less than 1" long; coma reddish-brown.
In low grounds, Maine to Ontario, Wisconsin, Nebraska, South Carolina, Tennessee and Kansas. Ascends to 2000 ft. in Virginia. Autumn basal shoots forming rosettes of leaves, as in the following species. July-Sept.
Epilobium glandulosum Lehm. in Hook. Fl. Bor Am. 1: 206. 1833 ?
Epilobium adenocaulon Haussk. Oest. Bot. Zeit. 29: 119. 1879.
Closely resembling the preceding species, but the inflorescence and capsules glandular-pubescent. Leaves lanceolate or ovate-lanceolate, obtusish or sometimes acute, sparingly serrulate or denticulate, seldom over 2$' long; flowers usually nodding at first; seeds obovoid, abruptly short-beaked, about \" long, papillose; coma white.
In moist grounds, Newfoundland to British Columbia, Massachusetts, Delaware, North Carolina, Iowa, New Mexico and California. Ascends to 4000 ft. in the Adirondacks. July-Sept.
E. Hornemanni Reichenb. Icon. Crit. 2: 73. 1824.
E. alpinum var. majus A. Gray, Man. Ed. 5, 177. 1867.
Erect, 6'-12' high, simple or nearly so, slightly pubescent above, otherwise glabrous. Leaves short-petioled, ovate or elliptic, acutish or obtuse at the apex, narrowed or rounded at the base, entire or rather remotely denticulate, thin, 6"-2o" long, 4"-10" wide; flowers few in the upper axils, purple or violet, 3"-3i" broad; stigma entire; capsules 1'-2 1/2' long, nearly glabrous, slender-pedicelled; seeds about 1/2" long, papillose, nearly beakless; coma dingy-white.
Moist places, Labrador to Maine, New Hampshire, British Columbia, south in the Rocky Mountains to Colorado and to California. Also in Europe and Asia. Summer.