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..
Gaura parviflora Dougl.; Hook. Fl. Bor. Am. 1: 208. 1832.
Erect, branched, villous-pubescent with whitish hairs, 2°-5° high. Leaves ovate-lanceolate, acute or acuminate at the apex, repand-den-ticulate, narrowed at the base, softly pubescent, 1 1/2-4' long, 4"-18" wide; spikes elongated, usually densely flowered; flowers sessile, pink, 1 1/2-2" broad, the ovary and calyx-tube slender; fruit sessile, narrowed at the base, 4-nerved, obtusely 4-angled, glabrous or nearly so, 3"-4" long.
Gaura coccinea Pursh, Fl. Am. Sept. 733. 1814.
G. marginata Lehm.; Hook. Fl. Bor. Am. 1: 208. 1833.
Erect or ascending, much branched, canescent, pubescent or glabrate, 6-2° high. Leaves oblong, lanceolate, or linear-oblong, denticulate, repand or entire, acute or obtuse at the apex, narrowed at the base, 6"-18" long, 2"-4" wide; flowers sessile, red, turning scarlet, 4"-5" broad; fruit sessile, terete below, 4-sided and narrowed above, canescent, 3"-4," long.
Gaura glabra Lehm. differs in having a glabrous shining stem, the foliage also glabrous or nearly so, the flowers often paler in color. It ranges from South Dakota to Nebraska, Montana and New Mexico, and is probably a race of G. coccinea.
Gaura biennis L. Sp. Pl. 347. 1753.
Erect, much branched, villous or downy-pubescent, 2°-s° high. Leaves lanceolate or oblong-lanceolate, acute or acuminate at each end, pubescent or finally glabrate above, remotely denticulate, 2'-4' long, 2"-5" wide; spikes slender; flowers sessile, white, turning pink, 4"-5" broad; fruit sessile, narrowed at each end, 4-ribbed, villous-pubescent, 3"-4" long.
In dry soil, Quebec and Ontario to Minnesota, Connecticut, Georgia, Nebraska and Arkansas. Ascends to 2200 ft. in Virginia. July-Sept.
Western races are shorter-pubescent and thicker-leaved than eastern, and have been separated as a species, Gaura Pitcheri (T. & G.) Small.
Perennial, erect or decumbent, glabrous, or rarely sparingly villous. Stem branched at the base or throughout, 1°-3° tall, usually naked above; leaves oblanceolate to lanceolate, or nearly linear, sinuate-toothed, 1'-3' long, acute, on winged petioles or nearly sessile; calyx slightly pubescent, its tube above the ovary funnelform, 1"-2" long, several times shorter than the linear segments; petals oblong-obovate,4"-5"long; stamens shorter than the petals; fruit about 7" long, glabrous, 4-ridged and 4-grooved above the stout club-shaped pedicel.
In dry soil, Kansas to Arkansas and Texas. Wild honeysuckle. May-July.
Gaura vilosa Torr. Ann. Lye. N. Y. 2: 200. 1827
Perennial, erect or neany so, canescent or villous. Stems 1°-3° tall, simple or much branched, often naked above; leaves varying from lanceolate to oblanceolate or sometimes nearly linear, 1-3' long, sinuate-toothed or pinnatifid, acute or acuminate, sessile; calyx canescent, its tube above the ovary funnelform, 1"-2" long, several times shorter than the linear acute segments; petals oblong-obovate, 5"-7" long; stamens shorter than the petals; fruit about 5" long, sparingly pubescent, the body sharply 4-angled, abruptly narrowed into a slender filiform pedicel.
In dry soil, Kansas to Arkansas and Texas. Wild honeysuckle. June-Sept.