Herbs with watery or resinous sap and alternate, opposite or basal leaves; flowers perfect, pistillate or neutral; borne on a common receptacle forming heads, surrounded by an involucre of few to many bracts in one or more series; calyx tube attached to the top of the ovary, the limb (pappus) of bristles, awns, teeth, scales, crown-like or wanting; corolla tubular, usually 5-lobed or -cleft, the marginal flowers frequently expanded into a ligule (ray); when the ray flowers are absent the head is said to be discoid, when present, radiate; the tubular flowers form the disc. The largest of all the families of flowering plants comprising about 760 genera and not less than 10,000 species, represented in the region by the following:

Stems numerous from a woody rootstock, rough-hairy throughout, spreading, 6—12 inches long. Leaves spatulate to oblong, entire, spreading, ¾—1½ inches long, obtuse at the apex, narrowed at the base, often into petioles half as long as the blade or more. Heads very numerous, about ½ an inch broad; involucre less than ½ an inch high, its bracts lanceolate, rough-hairy; ray flowers bright yellow, ¼ of an inch or more long.

In dry soil through the lower valleys throughout the Rockies; flowering in midsummer.

Stems smooth or somewhat hairy above, slender, 6—15 inches high. Leaves firm, smooth or nearly so, the basal and lower ones spatulate or oblanceolate, entire or sparingly serrate, obtuse, finely reticulate-veined, 3—5 inches long, the upper smaller and narrower, entire. Heads about ⅓ of an inch high, usually few in a rather compact terminal cyme; bracts of the involucre thin, linear-lanceolate, acute, smooth; rays 8—15, large.

On open hillsides throughout the region; flowering in July.

Stems clustered at the summit of a strong, perpendicular root, stout, decumbent, 6—18 inches high, usually dark red and sparsely hairy. Leaves spatulate-obovate to oblanceolate, obtuse or acutish, more or less distinctly serrate toward the summit, upper cauline leaves similar but few and reduced, all rough on the margins. Heads large in a thyrsoid panicle; bracts of the involucre glandular-viscid, linear, obtuse, of firm texture, nerved; rays large.

Smooth, rather slender, 3—5 feet high. Leaves firm or thick, those of the stem linear-lanceolate and sessile, acuminate at the apex, narrowed at the base, 2—4 inches long, rough-margined, triple-nerved, entire or sparingly serrate with low sharp teeth, the basal and lowest ones longer, spatulate and petioled. Heads ⅛—¼ of an inch high on one side of the spreading or recurving branches of the short panicle; bracts of the involucre oblong, greenish-tipped, obtuse; rays 6—13, short.

In dry soil on the edges of woodland at the lower altitudes throughout the Rockies; flowering in August.

Stout, rough-hairy or slightly so, 2—8 feet high. Leaves lanceolate, triple-nerved, acute at each end, the lower ones sharply serrate and petioled, 3—6 inches long, ⅓—1 inch wide, the upper smaller, entire. Heads small, ⅛ of an inch or less high, very numerous on one side of the spreading or recurved branches of the usually large and dense panicle; involucral bracts linear, obtuse or acutish; rays 9—15 small.

In open usually dry soil at the lower altitudes throughout the Rockies; flowering during July and August.

Stems 1—6 inches high, several from the same root. Leaves few, the basal spatulate or oblanceolate, 1—2 inches long; stem leaves linear and few. Heads ⅓ of an inch in diameter, solitary; involucre usually rough-hairy as well as woolly, bracts linear acute, rather close, rays ¼—⅓ of an inch long, white, very numerous.

An alpine plant in dry ground at the higher elevations, among stones and on the moraines, flowering in July.

Soft hairy above, 12—20 inches high. Leaves smooth, thick, bright green, spatulate or nearly ovate, acute or conspicuously bristle-tipped, the uppermost small and bract-like. Heads over 1½ inches in diameter; rays 50—70, purple or violet, ½—¾ of an inch long; disc bright yellow; involucral bracts linear, attenuate and spreading, glandular-hairy.

A most striking violet or purple daisy on moist banks, slopes, and in moist, open woodlands; flowering during July.

Stem simple or branched above, more or less hairy, sometimes roughly so, 6—24 inches high. Leaves smooth, hairy or fringed on the margin with hairs, entire, the basal ones spatulate, obtuse, 2—4 inches long, narrowed into a margined petiole; stem leaves oblong-lanceolate or linear-lanceolate, obtuse or acute, the upper smaller. Heads several or solitary, slender peduncled, ⅓—½ an inch broad; involucre hemispheric, its bracts linear, acute, or rough-hairy; rays 100—150, very narrow, violet-purple or nearly white, ⅓ to nearly half an inch long.

In dry soil in the lower valleys and slopes of the Rockies; flowering in July.

Stems tufted, closely white-hairy from a deep root; simple or branched above, 6—12 inches high. Leaves white-hairy, entire, narrowly oblanceolate or spatulate, obtuse or acutish, 1—3 inches long; stem-leaves linear or linear-oblong, acute or obtuse, the upper gradually shorter. Heads solitary or several, short-peduncled, ⅓—½ an inch broad; involucre hemispheric its bracts lanceolate or linear-oblong acute, white-hairy; rays 40—60, ¼—⅓ of an inch long, white or pinkish.

In dry open places in the Rockies at the lower altitudes, a pretty tufted plant resembling an Aster; flowering during July.

Rough-hairy or somewhat smooth, stems slender, numerous, 3—6 inches high. Leaves crowded on the crowns of the caudex, usually twice ternately parted into linear or spatulate hairy lobes; an inch long or less including the petiole; stem-leaves narrow or scale-like. Flowers solitary at the top of the nearly leafless hairy stem; involucre ¼ of an inch high and nearly ½ an inch in diameter, outer bracts shorter and spreading; rays 40—60, white, purple or violet, from ⅛ to nearly ½ an inch long.

On dry rocks throughout the Rockies up to 6000 feet elevation or above, flowering during June or July.

Erigeron multifidus discoideus (A. Gray.) Rydb., differing from the species in the entire absence of ray flowers and smaller heads, and Erigeron multifidus nudus Rydb., differing from the species in being almost entirely smooth except a few hairs on the petioles and involucral bracts, are found in similar localities throughout the Rockies, often growing with the species and frequently much more abundant.

Ashy-hairy, 3—6 inches high from a tufted caudex. Leaves ovate, spatulate or roundish, an inch or more long, contracted into a petiole; stem leaves ¼ of an inch long, few, and very narrow. Flowers solitary, about ⅓ of an inch high and broad; involucre usually reddish or purplish, covered with woolly hairs; bracts nearly equal, lanceolate, rather loose; rays numerous, ¼—⅓ of an inch long, deep golden yellow.

In open ground on alpine meadows and among rocks, at the higher altitudes, throughout the region; a striking little plant, flowering in July.

Stems few or several, slender, erect, 2—6 inches high, with purplish-black hairs. Leaves numerous, elliptic or narrowly oblong, ¾—1½ inches long, nearly smooth; stem leaves broadly linear, acuminate, ¾—1 inch long, hairiness similar to that of the stem. Head solitary, ⅓ of an inch broad; involucral scales nearly equal, with attenuate tips, densely covered with purplish-black wool; rays 50—60, white or pinkish, ⅛ of an inch long.

In open stony or more or less grassy ground at the high altitudes; flowering during July.

More or less hairy, varying to smooth, 3—18 inches high, simple or branching. Leaves spatulate or lanceolate, obtuse, 1—3 inches long, hairy and entire. Heads ¼ of an inch or more broad, single or several, more or less paniculately disposed; involucre hemispheric, its bracts linear and hairy; rays numerous, very narrow, only slightly exceeding the yellow disc, blue or purple.

In dry stony ground and slopes throughout the region, very variable as to size; flowering during July.

Nearly or quite smooth, 1—2 feet high, usually paniculately branched. Leaves spatulate to lanceolate, acute, rather numerous. Heads on peduncle-like branches, an inch or more long, involucre, ⅓ of an inch or more broad, scales narrowly lanceolate, attenuate and glandular, green; rays numerous and thread-like, pink, but slightly exceeding the disc.

On banks and more or less shaded places at the lower altitudes throughout the Rockies; flowering during July.

Soft-hairy or sometimes nearly smooth, stems slender, mostly branched above, 1—3 feet high. Leaves spatulate or obovate, obtuse or acute, dentate or entire, 1—3 inches long. Heads several or numerous, corymbose-paniculate, ¼—⅓ of an inch broad; involucre depressed hemispheric, its bracts linear with roughened margins; rays 100—150, ¼—⅓ of an inch long, bright rose-colour.

In open grassy and wet places at the lower altitudes, throughout the Rockies; flowering in June and July. This species, the most widely distributed of any member of the genus, is found throughout North America; though locally rare, where found it is usually in great abundance.

Hairy, often much branched from the base, 3—12 inches high. Leaves oblong, spatulate to broadly lanceolate, more or less sharply serrate, an inch or more long. Heads solitary, terminating the stem or branches; involucre broadly campanulate, ¼ of an inch high, shorter than the disc; the bracts narrowly lanceolate, with mostly acute and loose herbaceous tips; rays nearly half an inch long, violet-purple.

In gravelly ground and river bottoms frequent in the region; flowering during July.

Rough, stout, and rigid, 2 feet high. Leaves firm, ovate, oblong, or the lower obovate, acute, 4—6 inches long, 1½—4 inches broad, acutely serrate, reticulate-veiny. Flowers numerous in a broad head, involucre, broadly campanulate, equalling the disc, half an inch high; bracts in several series, minutely glandular, lanceolate, acute, the greenish tips a little spreading; rays ½ an inch long or more, violet.

The most showy of all the Asters, frequent in the Rockies at the lower altitudes, on slides and on gravelly river banks, forming great masses of colour when flowering in late July and early August.

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.

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.

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.

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.

Slightly hairy or smooth, simple or somewhat branched, 18 inches to 2 feet high, bright green. Leaves thin, ovate-oblong to broadly lanceolate, 2—4 inches long, loosely veined, tapering at the apex into a slender-spined tip, the larger sometimes with a few small acute teeth. Heads ½ an inch high, hemispherical, either racemosely disposed on slender axillary peduncles, or somewhat cymose; involucral bracts mostly acute or acuminate, some outer ones loose, narrow, and partly herbaceous, or with loose pointed tips; inner purplish; rays about ½ an inch long, spreading, violet or pinkish.

In open woods and on slopes, principally in the Rockies at the higher elevations; flowering during July.

Rough-hairy throughout, stems simple or sparingly branched, often tufted, 1—3 feet high. Leaves thick, sparingly serrate with low teeth or entire, lanceolate or oblong, the lower and basal ones petioled, mostly obtuse, 3—5-nerved, 2—7 inches long, ½—2 inches wide, the upper sessile, narrower, acute or acutish. Heads commonly few or solitary, 2—4 inches broad; rays 10—20, deep yellow or orange; bracts of the involucre very rough-hairy; spreading or reflexed, much shorter than the rays; disc globose-ovoid, purple-brown.

Throughout the region, not infrequent along the railway from Field west to the valley of the Columbia at Beavermouth; flowering in July and August.

Stems simple or a little branched, rough-hairy or only slightly so, 1—8 feet high. Leaves thick, leathery, serrate, rough-hairy on both sides, 2—7 inches long, ½—2 inches wide, acute at the apex, narrowed at the base, the lower ovate or ovate-oblong, petioled, the upper lanceolate or oblong-lanceolate, sessile or short-petioled, all opposite, or the uppermost bract-like and alternate. Heads solitary or few, 2—3 inches broad, involucre hemispheric, its bracts ovate, acute or obtuse, fringed with hairs; disc brown or purple; rays 15—25, light yellow.

Frequent along the railway in the valley of the Kicking Horse River and in the valley of the Columbia at Beavermouth; flowering in August.

Stem smooth, except the summit which is soft-hairy, slender, mostly simple, 2—4 feet high. Leaves rough on both surfaces, lanceolate or the upper linear, 3—6 inches long, ¼—¾ of an inch wide, frequently opposite, serrulate or entire. Heads ½ an inch high, scattered; bracts of the involucre linear-lanceolate with a subulate tip, hairy at the base; rays narrow, acute, deep yellow, 1—1½ inches long.

In moist grounds and on river banks throughout the Rockies at the lower altitudes; flowering during July.

Rough-hairy, stems simple or little branched, 1—3 feet high. Leaves firm, densely and finely hairy, the lower basal ones petioled, oblong or spatulate, laciniate-pinnatifid or entire, mostly obtuse, 2—5 inches long; upper leaves sessile, lanceolate or oblong, entire or dentate, rarely pinnatifid. Heads 1½-4 inches broad, long peduncled; bracts of the involucre spreading, lanceolate, acuminate, rough-hairy, rays 10—18, bright yellow, wedge-shaped, deeply 3-lobed; disc reddish-purple.

One of the most showy of the midsummer plants, in the lower valleys of the Rockies, in dry ground and on slopes, especially in the Bow Valley at Banff and in the open country around Golden.

Somewhat hairy, stem simple or sparingly branched, 1—2 feet high. Leaves hairy, the basal ovate or orbicular, obtuse or acute, deeply cordate at the base, dentate, 1—3 inches long with slender sometimes margined petioles; stem leaves in 1—3 pairs, ovate or oblong, sessile or short-petioled, much smaller. Heads 1—8, 2—3 inches broad, bracts of the involucre, acute or acuminate, ½—¾ of an inch long; rays 12—16, deep yellow, an inch or more long, toothed at the apex; pappus white.

In woods and thickets at the lower altitudes throughout the Rockies; flowering in June.

Smooth, slender and branched, 6—12 inches high. Leaves with short glandular hairs on both surfaces or smooth, the basal broadly ovate, petioled, dentate, 3-ribbed; stem-leaves about 2 pairs, similar, the upper sessile. Heads several on slender glandular peduncles, disc ½ an inch or less high; involucral bracts, 12—15, lanceolate, acuminate, glandular-hairy as are also the seeds; pappus white; rays about ¾ of an inch long, narrow, bright yellow with a single notch at the apex.

On alpine slopes throughout the Rockies; flowering in July, not common.

Minutely hairy or nearly smooth, simple or branched. Leaves thin, nearly smooth, or with long scattered hairs; the lower cordate; stem leaves in 2—3 pairs, equal, ovate or oval, sharply dentate, closely sessile by the broad base, or the lowest with contracted bases. Heads ¾ of an inch high on long, slender, hairy peduncles; involucral bracts ½ an inch or more long; oblong-lanceolate, acuminate, with scattered hairs, rays yellow, ¾ of an inch long, with 2 notches at the apex; achenes nearly smooth; pappus white.

Throughout the region in woods and open ground usually at an elevation of 5000 to 7000 feet; flowering during July.

From lightly hairy to densely so or nearly smooth, 1—2 feet high. Leaves rather thin, hairy, oblong to oblong-lanceolate, dentate or denticulate, acute or obtuse, lowest tapering into a margined petiole, upper broad at the base and somewhat clasping. Heads ½ an inch or more high, single or several on hairy peduncles; involucral bracts ⅓ of an inch or more long, oblong-lanceolate, acuminate, glandular-hairy; rays bright yellow, ½ an inch or more long with a single notch at the apex, rather broad; achenes with a few scattered hairs; pappus tawny.

On the borders of streams and wet places at the lower altitudes throughout the region; flowering in July.

Slender, hairy, 3—8 inches high. Leaves in about 3 pairs, the two lowest at the base of the stem, 1½—2 inches long, elliptical or obovate, entire or denticulate, glandular-hairy on both surfaces, as are the margins. Heads of flowers, 1—3, nearly half an inch broad, on long, slender, nodding, hairy peduncles; rays 8—10, light yellow, about ½ an inch long; involucre ⅓ of an inch high, campanulate, densely glandular-hairy at the base, brownish-purple, the bracts lanceolate, acute, with scattered white hairs; pappus white.

Among loose stones at the base of Mt. Fairview at Lake Louise; flowering in July.

Glandular-hairy throughout, 8—12 inches high. Leaves oblong lanceolate to lanceolate, acute, the lower denticulate and petioled, the upper sessile and entire. Heads of flowers several on long, slender, glandular-hairy peduncles; involucres campanulate, ½ an inch high, bracts lanceolate acute, glandular and with long white hairs; rays bright yellow ¾—1 inch long, ¼ of an inch wide, twice notched at the apex; achenes hairy; pappus white.

On stony alpine slopes at the higher altitudes throughout the Rockies; flowering in July.

Densely soft-hairy throughout; simple or branched, 12—18 inches high. Leaves oblong, ovate-lanceolate or the upper ones lanceolate, obtuse or acute, entire or sharply denticulate, 1—3 inches long. Heads of flowers on short, hairy peduncles, without rays; involucre ½ an inch high, bracts lanceolate, acute; achenes black, smooth or nearly so; pappus tawny.

On grassy alpine slopes through the Rockies at the higher elevations; flowering in July.

Smooth from a creeping rootstock, 1—2 feet high. Leaves smooth, basal broadly ovate, somewhat cordate, serrate, 1½—3 inches long, long-petioled; stem leaves more or less laciniate at the base, the upper sessile. Heads of flowers ⅓ of an inch high in a flat-topped corymb, rays bright orange-yellow, ⅓ of an inch long.

In moist ground and borders of woods and slopes throughout the Rockies at the lower altitudes; flowering during June and early July.

Smooth except for the small tufts of wool in the axils of the lower leaves; stem rather stout, 1—2 feet tall. Basal leaves oval or ovate, thin, sharply dentate, abruptly narrowed into petioles longer than the blade; stem leaves few, small, more or less irregularly cut. Heads few or numerous, corymbose; bracts of the involucre narrowly linear, nearly ½ an inch high; rays very short or wanting; achenes smooth.

Frequent throughout the Rockies on river shores and borders of woods and thickets; flowering in July.

Light or yellowish-green, slender, woolly in tufts at the base of the leaves or smooth in age; stem 12—18 inches high, striate, pale. Leaves 1—3 inches long, at the base obovate or broadly oval, generally tapering into the petiole but sometimes truncate at the base, obtuse, crenate or sinuate, light green; lower stem-leaves lanceolate in outline and petioled, the upper lanceolate or linear and sessile, deeply pinnatifid with narrow oblong or linear segments, cymes contracted, corymbose. Heads ¼ of an inch or more high; bracts linear, acute, yellowish-green and occasionally with brownish tips; rays pale yellow, ½ an inch long, 4-nerved or often lacking.

In the lower valleys of the Rockies, on the borders of woods, thickets, and marshes; flowering in July.

Permanently silvery-hairy with felted hairs; stems several, 6—12 inches high from a woody base. Leaves sometimes all undivided, the radicle and lower from spatulate to oblong or roundish-oval, ½—1½ inches long, slender-petioled, sometimes laciniate-toothed, or pinnatifid. Heads of flowers few and terminal, ⅓ to nearly half an inch high; rays yellow, nearly ½ an inch long.

In stony dry ground and slopes throughout the Rockies at the lower altitudes; flowering in June.

More or less woolly when young, soon smooth; stem stout, 1—3 feet high. Basal and lower leaves oblong or oval, obtuse or acute, denticulate or dentate, 2—5 inches long, ½—1½ inches wide, narrowed into margined petioles; upper leaves few, sessile, small and bract-like. Heads of flowers several or numerous, corymbose, often short-peduncled, ½ to nearly an inch broad; involucre campanulate, ¼—⅓ of an inch high, its bracts lanceolate to oblong-lanceolate, acute, green with conspicuous black tips; rays 10—12, bright yellow, ½ an inch long.

In moist soil at the lower altitudes throughout the Rockies; flowering in June.

Rather stout, simple, 2—5 feet high. Leaves thin, all more or less petioled and dentate, deltoid-lanceolate or the lower triangular-hastate or deltoid-cordate, the uppermost lanceolate, with cuneate base. Heads of flowers about ½ an inch high, numerous in a flat open cyme; involucre campanulate; rays 8—12, bright yellow, oblong-linear, ¼—⅓ of an inch long.

In wet ground and along the borders of streams and wet slopes at 5000 to 6000 feet elevation throughout the Rockies; at much lower altitudes in the Selkirks where it is a very abundant plant; flowering in June and early July.

Scape slender and scaly, 6—24 inches high. Leaves nearly orbicular in outline, 3—12 inches broad, deeply 7—11-cleft to much beyond the middle, green and smooth above, densely white-woolly beneath, at least when young; the lobes oblong to obovate-acute, often somewhat wedge-shaped, sharply dentate or cut. Heads mostly diœcious, numerous, corymbose, ⅓—½ an inch broad; flowers usually white, fragrant, the marginal ones of the pistillate heads with narrow pinkish or white rays about ¼ of an inch long; cottony in fruit.

In wet places and along streams at the lower altitudes throughout the Rockies; flowering in May and early June before the leaves appear.

Scape slender and scaly, 6—12 inches high. Leaves deltoid-ovate or reniform-ovate, persistently white-tomentose beneath; smooth or nearly so above, 4—10 inches long, thin, margins sinuate-dentate, not cleft or lobed. Heads diœcious, loosely corymbose, involucre campanulate, ⅓ of an inch high; flowers nearly white, the marginal ones of the pistillate heads with white rays.

In similar situations to the preceding; in wet places and along streams at the lower altitudes throughout the Rockies; readily distinguished by the shape of its leaves; flowering in May and early June.

Scape very, scaly, 3—10 inches high. Leaves thin, hastate-reniform to triangular-ovate, 1—4 inches long, irregularly and angulately lobed and incised, smooth and green above, persistently white-woolly beneath, the lobes entire or few-toothed. Heads usually few, ½ an inch or more high in a capitate corymb; involucre short, campanulate; flowers nearly white and fragrant, the marginal ones of the pistillate heads with white or pinkish rays ¼ of an inch or more long.

In shaded wet places and along alpine brooks at the high altitudes throughout the region; flowering during June and July with the expanding leaves.

Woolly throughout; stems simple, 6 inches to 2 feet high. Leaves narrowly oblong in outline, bi-pinnately dissected into numerous small linear divisions. Heads numerous, crowded into a rather contracted cyme; involucre oblong, nearly ¼ of an inch high; bracts lanceolate, green with brown translucent borders; rays 4—5, white, broadly obovate, notched and spreading, about the length of the involucre.

Open ground, slopes and meadows throughout the region; flowering during July.

Smooth, simple, 1—3 feet high, often tufted, the branches nearly erect. Leaves smooth, the basal oblong or spatulate, coarsely dentate or incised, narrowed into long, slender petioles; stem-leaves mostly sessile or partly clasping, 1—3 inches long, linear, pinnately-incised or toothed, the uppermost small, nearly entire. Heads few or solitary, 1—2 inches broad on long naked peduncles, rays 20—30, white and spreading; disc flat, bright yellow, bracts of the involucre lanceolate or obtuse, smooth with translucent margins.

In open ground throughout the region; flowering during July.

Simple or branching, silky-hairy and silvery throughout; stems numerous and spreading, about a foot high. Leaves mainly twice ternately divided into linear crowded lobes. Heads globular, about ⅛ of an inch in diameter, numerous, in more or less racemose heads; involucre pale, greenish-yellow, woolly; bracts narrow and herbaceous.

In open dry ground and on banks throughout the Rockies at the lower altitudes; flowering in July.

Stems slender, 9—12 inches high, spreading from a woody base. Leaves pinnately parted into narrow, linear or lanceolate, entire or spreading cut divisions and lobes, white beneath with cottony hairs, green and nearly smooth above. Heads ⅛ of an inch high, numerous in a wand-like panicle; involucre hemispherical-campanulate, greenish and smooth or nearly so, 20—30 flowered.

On Rocky slopes throughout the region; flowering in June or July.

Densely white-woolly; stem simple, 2—6 inches high. Lower leaves spatulate-lanceolate, 1—1½ inches long, the upper linear with conspicuous papery tips. Heads several in a close cluster at the end of the stem, ½ an inch high; involucre nearly ¼ of an inch high, conspicuously woolly at the base, the inner bracts with conspicuous white tips, the outer straw-colour or greenish.

An alpine plant in meadows and on slopes from 7000 feet up; flowering during July.

White-woolly throughout, stem simple, 6—18 inches high. Leaves spatulate to lanceolate or linear, 1—4 inches long, acute, nerved. Heads numerous in a close capitate cluster, ½—1 inch high, outer bracts of the involucre straw-colour or greenish, rounded and often notched at the apex; inner ones nearly white.

In moist open ground in the Rockies at the lower elevations; flowering in July.

Lightly woolly, becoming smooth, stems 6—20 inches high, slender, sparsely leafy. Leaves thin, the radicle broadly oval, an inch or two long, obscurely 3-nerved at the base, rather veiny, the lower stem leaves oblong, the upper smaller and lanceolate. Heads of flowers about ¼ of an inch high, all on slender peduncles in a loose raceme, involucral bracts, thin and translucent, greenish-yellow or brownish.

On shaded slopes throughout the Rockies, at the higher altitudes; flowering in June.

More or less woolly; stem 6—10 inches high. Leaves rather thin, the lower spatulate, acute, 1—2 inches long, green above, woolly beneath; stem leaves lanceolate, clasping, 1 inch long, becoming smaller toward the summit. Heads in a compact capitate cluster, ½ an inch or more in diameter, woolly at the base; involucral bracts very narrow, acute, thin, and translucent, straw-colour, the outer ones densely woolly and occasionally rosy.

In dry ground and on slopes, frequent in the Rockies at the lower altitudes.

Plant silvery throughout, freely spreading; stems prostrate and leafy, forming mats of considerable extent; flowering stems 2—8 inches high. Leaves from obovate to spatulate, ½ an inch or less long, persistently white-woolly. Heads in compact terminal clusters about ⅓ of an inch broad; involucral bracts, lanceolate, obtuse, thin and translucent, yellowish.

In dry sterile ground at the lower altitudes throughout the Rockies; flowering in June, frequently growing with the next species which it closely resembles in manner of growth.

Silvery throughout, stems prostrate and leafy, forming broad mats; flowering stems 6—15 inches high. Leaves very thin in texture, densely hairy, lanceolate to linear, ½—1½ inches long, acute. Heads small, closely compacted into a rounded terminal cluster, ½ an inch or more in diameter; involucral bracts in 2 series, lanceolate, the outer greenish and woolly, the inner from pink to bright rose-colour.

In dry sterile or moist open ground throughout the Rockies up to an elevation of 6,000 feet; flowering in June and July.

A foot or two high in tufts, very leafy, the white tufts of woolly hairs rarely becoming tawny. Leaves 2—5 inches long, broadly lanceolate, green above, white-woolly beneath. Heads numerous, ¼ of an inch high in a contracted corymb; involucral bracts numerous, ovate-lanceolate, pearly white, spreading in age.

Abundant throughout the region in dry or moist ground and on slopes up to an altitude of 7000 feet; flowering in June and July.