This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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..
Tufted scapose or branching herbs, with alternate, entire, linear or spatulate leaves, and large heads of both tubular and radiate flowers. Involucre hemispheric or broadly campanulate; bracts imbricated in several series, the outer shorter. Receptacle nearly flat, naked or fimbrillate. Ray-flowers pink or white, pistillate. Disk-flowers tubular, mostly perfect, their corollas regular, 5-lobed. Anthers obtuse and entire at the base. Style-branches flattened, their appendages lanceolate. Achenes of the disk-flowers compressed, those of the rays commonly 3-angled. Pappus a single series of rigid bristles or short scales. [Named for David Townsend, botanist, of Philadelphia.]
About 25 species, natives of western North America. Type species: Townsendia sericea Hook. Branching from the base; heads terminal.
1. T. grandiflora.
Acaulescent, or nearly so; heads sessile among the leaves.
2. T. exscapa.
Townsendia grandiflora Nutt. Trans. Am. Phil. Soc. (II) 7: 306. 1841.
Perennial from a long woody root, branching at the base and sometimes also above, pubescent, or at length glabrate, 2'-8' high. Leaves linear or linear-spatulate, 1'-3' long, 1 1/2"-3" wide, canescent heads 1'-1 1/2' broad, solitary at the ends of the branches; involucre hemispheric, its bracts scarious-margined, lanceolate, conspicuously acuminate; rays violet or purple; pappus of the ray-flowers a crown of short scales, that of the disk-flowers of rigid bristles longer than the achene, which is pubescent with 2-toothed hairs.
In dry soil, South Dakota to western Nebraska, Wyoming, Texas and New Mexico. May-Aug.
Aster (?) exscapus Richards. App. Frank. Journ. 32. 1823. Townsendia sericea Hook. Fl. Bor. Am. 2: 16. pl. 119.
1834. Townsendia exscapa Porter, Mem. Torr. Club 5: 321. 1894.
Acaulescent, or nearly so, from a deep woody root, tufted, 1'-3' high. Leaves all clustered at the base, narrowly linear or slightly spatulate, 1'-2' long, 1"-2 1/2" wide; heads closely sessile, 1'-1 1/2' broad, equalled or surpassed by the leaves; involucre broadly campanu-late, its bracts lanceolate, acute, the inner scarious-margined; rays white or purplish; pappus of both ray- and disk-flowers a row of rigid bristles, those of the rays shorter and smaller.
In dry soil, Saskatchewan to Montana, Nebraska, Texas and New Mexico. Often silky-pubescent. April-July.
Townsendia intermedia Rydb., ranging from Nebraska and Colorado to Texas, appears to be a race of this species with leaves wider than in the type.