[Sidenote: =Aster major= (Hook) Porter. _Great Northern Aster._] Stem stout, leafy to the summit, densely long-hairy, or rarely smooth, branched above, 2—6 feet high. Leaves rather thin, lanceolate, partly clasping by a narrowed base, acuminate at the apex, sharply serrate with low distant teeth, dark green and lightly hairy above, densely soft-hairy on the veins beneath, 3—5 inches long, ½ to nearly an inch wide. Heads mostly solitary, at the ends of short branches, 1½ inches broad; involucre hemispheric, its bracts little imbricated, green, linear-subulate, densely glandular; rays 35—45 purple, about ½ an inch long. In moist soil in the valleys of the Selkirks; flowering during August. [Sidenote: =Aster Lindleyanus= T. & G. _Lindley’s Aster._] Stem usually stout, smooth, or sparingly hairy, 1—3 feet high, branched above. Leaves rather thick, smooth or slightly hairy, especially on the veins, the lower and basal ones heart-shaped at the base, sharply serrate, ovate-acute or acuminate, 2—4 inches long, with slender, naked petioles; upper leaves ovate-lanceolate or lanceolate, more or less serrate or entire, sessile or with margined petioles. Heads usually not numerous, ⅓ of an inch or more high; involucre broadly top-shaped; bracts linear-lanceolate, acute, rather loosely imbricated, smooth or nearly so, their tips green, rays 10—20, blue or violet, ¼—½ an inch long; pappus nearly white. In open places and along the rivers throughout the region; flowering during July and August. [Illustration: Aster Lindleyanus T. & G. (⅔ Nat.)] [Sidenote: =Aster ciliomarginatus= Rydb.] Stems 1—2 feet high, round, slightly striate and tinged with red, smooth below, more or less hairy in lines above. Basal leaves smooth except the hairy-fringed margins, thin, distantly serrate or subentire, tapering into wing-margined petioles, oblanceolate-acute, 4—8 inches long; the upper oblong or lanceolate sessile. Heads about ½ an inch high, ½—¾ of an inch in diameter, rather few in an open panicle; involucral bracts linear, fringed with hairs on the margins, the upper part foliaceous and the outer somewhat spreading; rays numerous ½ an inch long, light blue. In moist, more or less shaded places, edges of woods and thickets, throughout the Rockies; flowering in late July and August. [Sidenote: =Aster frondeus= (A. Gray) Greene. _Leafy-bracted Aster._] Simple, stem smooth, with sparing, erect, flowering branches. Leaves few, broadly lanceolate to oblong or spatulate, entire or nearly so, the lower tapering into winged petioles. Heads solitary or few, on naked peduncles; involucre ⅓ of an inch high, or less; bracts linear-lanceolate, loose, all equalling the disc; rays violet or purple, nearly ½ an inch long. In wet places and along streams throughout the Rockies; flowering during July and August. [Sidenote: =Eucephalus Engelmanni= (D. C. Eaton) Greene. _Engelmann’s Aster._]