Herbs or vines with alternate, compound leaves and irregular, perfect, yellow, purple, blue, or white flowers, mainly in racemes; calyx 4—5-toothed; petals more or less united or separate, consisting of a broad upper one (standard), two lateral ones (wings), and two front ones more or less united (keel).

Stems whitish with close hairs or nearly smooth, ascending or decumbent, 4—18 inches long, simple or branched at the base. Leaflets 15—25 oval or linear-oblong, sometimes notched at the apex, narrowed at the base, ½—1 inch long; peduncles exceeding the leaves. Flowers purplish, ½—¾ of an inch long in dense short spikes; calyx villous with long partly black hairs, ½ the length of the corolla, with slender teeth, half the length of the campanulate tube.

In open ground at low altitudes, probably the most frequent of the vetches on the eastern slopes of the Rockies, often forming great patches of blue during June.

Hairy or nearly smooth, stems decumbent or ascending, slender, branched at the base, usually low, but ranging from 6—24 inches long. Leaves 2—5 inches long with 17—25 leaflets which are oblong or elliptic, obtusish and usually notched at the apex, rounded at the base ¼—½ an inch long. Flowers violet-purple, ½ to nearly an inch long in dense heads, calyx nearly ⅓ the length with long black and white hairs.

Frequent at the lower altitudes, in dry ground and roadsides on the eastern slopes of the Rockies, particularly in the region around Banff; flowering in early June.

Ascending or decumbent, branching from the base, 6—15 inches high, slightly hairy or smooth. Leaves 2—5 inches long, with 13—25 oval or elliptic, obtuse or retuse leaflets, narrowed or rounded at the base, ¼—½ an inch long. Flowers ½ an inch or more long, pale violet, the keel commonly darker, in short rather open racemes; calyx about ⅓ the length of the corolla, with short black hairs.

The most dainty of any of the vetches, frequent in rocky soil in slightly shaded situations throughout the Rockies at the lower altitudes; flowering during June and July.

Stems slender, ascending and rigid, 10—18 inches high, branching from the base; hairy throughout. Leaves 3—6 inches long with 9—17 narrowly linear, silky leaflets ½—1 inch long, remote. Flowers pale violet or mauve, half an inch or more long, scattered in a slender raceme 3—5 inches long; peduncles much longer than the leaves; calyx about ⅓ the length of the corolla with scattered white or brownish hairs.

On the eastern slopes of the Rockies in dry stony ground at the lower altitudes; flowering in early June.

Stems 18—24 inches high, stout and leafy, slightly striate and nearly smooth. Leaves 2—4 inches long, thin, odd-pinnate with 4—8 pairs of obtuse, oblong, or oval leaflets, ½—1 inch long. Flower scream-coloured, tinged with blue, in heads 1½—3 inches long, on peduncles 4—10 inches long, from the axils of the upper leaves; calyx ⅛ of an inch long, black-hairy, lobes very slender and short; corolla ¼ of an inch or more long.

Frequent in more or less moist open ground throughout the Rockies at varying altitudes; flowering during June and early July.

Erect, nearly simple and smooth, 1—2 feet high. Leaves 3—6 inches long with 7—17 oval or ovate-lanceolate obtuse leaflets, ¾—1½ inches long. Flowers white, ¾ of an inch long in loose racemes on peduncles equalling or exceeding the leaves; pedicels slender, ½ an inch long in fruit; pod membranous, inflated, an inch long.

In moist or wet rocky shaded places throughout the Rockies; flowering during June and early July.

Stems erect and branching, 6—18 inches high, hairy throughout, from an enlarged root. Leaves pinnate with 7—11 linear leaflets; stipules ovate, acute, foliaceous. Flowers white, tinged with mauve, in a loose raceme 1—2 inches long; peduncles longer than the leaves, calyx black-hairy, about ⅛ of an inch long, with slender teeth nearly half as much longer; corolla more than twice the length of the calyx.

An abundant species at the lower altitudes in open dry ground on the eastern slopes of the Rockies; flowering in early June.

Silvery-pubescent throughout, with appressed or slightly spreading hairs; tufted. Leaves basal, 3—6 inches long with 9—19 linear-oblong or lanceolate, acute or obtusish leaflets ¾—1 inch long. Flowers pale yellow or creamy-white ¾ of an inch or more long in dense heads, on peduncles longer than the leaves; calyx nearly half as long as the corolla, with long white and short black hairs.

Frequent throughout the Rockies in dry stony and alpine meadows and slopes, at varying elevations; flowering from June to early July.

Tufted, the branches of the caudex short; scapes few or several, erect, rather slender, 4—20 inches high. Leaves several, mostly erect, shorter than the scapes; leaflets 10—15 pairs, mostly oblong-lanceolate, from sparsely soft-pubescent to lightly canescent, acute, ½—1 inch long. Flowers pale yellow, ½ an inch long and twice as long as the calyx, in a loose head, 2—4 inches long.

Abundant in the open ground on the eastern slopes of the Rockies; a strikingly handsome vetch frequently found in masses of considerable extent, especially in the region around Banff; flowering in June and early July.

Densely silky, silvery-villous, acaulescent, and tufted. Leaves 4—9 inches long, erect; leaflets very numerous, in verticels of 3—6, oblong or oblong-lanceolate, acute or acutish at the apex, rounded at the base, ½ to nearly an inch long. Flowers deep purple, about ½ an inch long in dense spikes on peduncles exceeding the leaves.

A very showy plant frequently flowering in considerable masses in the open grounds on the eastern slopes of the Rockies and dry alpine meadows; flowering in June.

Tufted, with parts of the old leaves remaining. Leaves all basal, 4—6 inches long with 8—15 pairs of leaflets, loosely villous-pubescent, oblong, obtuse or acutish, ¼ to nearly ½ an inch long, glandular on the margins. Flowers nearly ½ an inch long varying from pink to dark purple, in loose spikes on glandular sticky scapes, much longer than the leaves; calyx more than half as long as the corolla with white and shorter black hairs; calyx teeth and bracts of the inflorescence densely glandular.

In dry open ground and alpine meadows through the Rockies at the lower altitudes, flowering in early June and forming dense tufted masses of brilliant pink, blue, or purple flowers; probably the most striking species in the vicinity of Banff.

Loosely soft-pubescent or silky, decumbent or ascending 10—18 inches high. Leaves 4—6 inches long with 12—16 pairs of lanceolate to oblong, acute leaflets, ¼—½ an inch long. Flowers small, pale purple, little more than ¼ of an inch long in slender spikes 2—4 inches long on peduncles much surpassing the leaves. Calyx nearly as long as the corolla, with short black and longer white hairs; fruit strongly reflexed.

In moist open ground throughout the eastern Rockies at the lower altitudes; flowering in July.

Acaulescent or more or less so, 1—4 inches high, soft-hairy. Leaves pinnate with 5—11 pairs of short linear-lanceolate or oblong leaflets. Flowers violet-purple, 1 or 2 on the peduncles which scarcely exceed the leaves; calyx densely dark-hairy; pods much inflated.

On high alpine slopes and summits through the Rockies, not a common plant but probably more general than is now known; flowering in July.

Stem erect or somewhat decumbent, smooth or nearly so, 6 inches to 2½ feet high, generally simple. Leaves 2—8 inches long with 11—21 oblong or oblanceolate-obtuse leaflets, ½ to nearly 1 inch long. Flowers violet-purple or nearly white, deflexed, ½—¾ of an inch long in rather loose elongated racemes; calyx teeth ovate-acute, shorter than the tube.

One of the taller of the vetches growing in open stony places and slides throughout the Rockies at the lower altitudes, flowering in July.

Erect, 12—15 inches high, minutely hairy. Leaves with 5—6 pairs of oblong-elliptic, obtuse-cuspidate leaflets, ½—¾ of an inch long, finely hairy beneath. Flowers bright yellow, over ½ an inch long; 15—30 in a rather dense raceme; wings exceeding the vexillum but shorter than the keel.

Throughout the Rockies in open woods and meadows up to 8000 feet elevation; flowering in June and July.

Stems erect or decumbent, 12—18 inches high, usually minutely hairy. Leaves 3—6 inches long with 11—19 oblong-elliptic leaflets about ½ an inch long. Flowers ¾ of an inch long, reddish-purple, 20—30 in loose racemes on peduncles longer than the leaves; calyx teeth very slender, longer than the tube.

On slides and in loose stony soil throughout the Rockies at varying altitudes; flowering during June and July.

Finely hairy or sometimes nearly smooth; stems tufted, slender, and weak, climbing or trailing 2—4 feet long. Leaves tendril-bearing 2—3 inches long of 18—24 thin, linear or linear-oblong, obtuse or acutish, mucronate leaflets, ⅓—¾ of an inch long. Flowers deep bluish-purple, ½ an inch long or less in dense spike-like racemes 1—4 inches long on peduncles equalling or exceeding the leaves.

In dry or moist soil throughout the Rockies at the lower elevations, flowering during June and July.

Smooth or some with appressed hairs, trailing or climbing 2—3 feet long. Leaves nearly sessile, 2—3 inches long, tendril-bearing, with 8—14 elliptic, ovate or oblong leaflets, ½—1½ inches long, obtuse or sometimes notched or mucronulate at the tip. Flowers bluish-purple about ¾ of an inch long, 3—9 in loose racemes, on peduncles usually shorter than the leaves.

In moist ground at the lower altitudes throughout the Rockies, climbing over the surrounding shrubs and herbaceous plants; flowering in July.

Smooth or nearly so; stems weak, often zigzag, 1—2 feet long. Leaves tendril-bearing, with 4—7 pairs of narrowly linear or linear-oblong leaflets, 1—3 inches long, entire, acute and mucronate at the tip. Flowers purple or purplish, about ¾ of an inch long, 2—6 in loose racemes, on peduncles shorter than or about equalling the leaves.

In dry soil at low altitudes throughout the Rockies especially near the line of the railway; flowering during July.

Smooth or sparingly hairy, stems angled and winged, slender, 1—3 feet long; stipules half sagittate, lanceolate-linear or ovate-lanceolate, ½ to nearly an inch long. Leaves with branched tendrils and 2—4 pairs of lanceolate oblong or linear, acute, mucronate leaflets; 1½—4 inches long. Flowers purple, half an inch or more long, 2—6 in loose-headed racemes on peduncles about equaling the leaves.

In wet ground and swamps at the lower altitudes throughout the region; flowering during July.

Stems slender, somewhat angled, trailing or climbing, smooth and slightly glaucous, 2—2½ feet long, stipules broad foliaceous, half ovate and half cordate, ⅓—1 inch long. Leaves with branched tendrils and 3—5 pairs of thin, ovate or broadly oval, obtuse leaflets, 1—2 inches long, green above, whitish beneath. Flowers yellowish or creamy-white ½—¾ of an inch long, 5—10 on peduncles shorter than the leaves.

On shaded river banks and hillsides at the lower altitudes throughout the Rockies; flowering during June.