Smooth herbs with opposite entire leaves, and regular perfect flowers in clusters or solitary at the ends of the stems or branches. Calyx 4—12-lobed; corolla 4—12-parted; stamens as many as the lobes of the corolla and alternate with them.

Stem leafy, slightly angled, simple or branched, 6—20 inches high. Basal and lower leaves spatulate or obovate, obtuse, the upper lanceolate, acuminate, rounded or subcordate at the base, sessile or somewhat clasping, ½—2 inches long. Flowers numerous in clusters in the axils of the upper leaves; pedicels ½—1 inch long, leafy bracted at the base; calyx deeply 5-parted, lobes lanceolate; corolla tubular campanulate, ½ an inch long, 5-parted, pale blue or greenish; lobes lanceolate, acute each with a fimbriate crown at the base.

Along stream banks and grassy slopes throughout the Rockies, common; flowering in July.

Stems slender, usually much branched from the base and sometimes also above, slightly wing-angled, 2—7 inches long. Basal leaves spatulate obtuse, the upper distant, oblong or lanceolate, ½—1 inch long, acute or obtusish at the apex, rounded at the slightly clasping base, obscurely 3-nerved. Flowers sometimes numerous, solitary on slender peduncles, mostly 4-parted, ½—¾ of an inch high, seldom opening; calyx 4-cleft, two of the lobes oblong, the others linear-lanceolate; corolla blue or bluish, glandular within at the base, the lobes ovate-lanceolate, entire or denticulate.

Frequent throughout the Rockies on slopes and open ground beside the trails; flowering through July.

Stems slender, 1—5 inches long, when prostrate the lateral ones often creeping. Leaves ovate, rather spreading, bright green with slightly whitened edges. Flowers solitary, 4-parted, azure blue, ½ an inch high, the lobes rather spreading.

A very small and rather rare plant found throughout the Rockies at the higher altitudes, on the alpine slopes and summits; flowering in July.

Perennial; stems 2—4 inches high. Leaves oval, glaucous, ¼—½ an inch long, obtuse, the basal forming a rosette. Flowers few or several at the top of the stem, short-peduncled or nearly sessile, usually subtended by a pair of bracts; calyx campanulate, the teeth shorter than the tube; corolla blue or blue-green, ½ an inch or more long, the tube cylindrical with short ovate obtuse lobes.

In wet alpine meadows and slopes throughout the region, a rather rare but very striking little gentian, flowering in July.

Stems clustered, 6—12 inches high, mostly ascending. Leaves from oblong or lanceolate to linear. Flowers from numerous and racemose to few and almost solitary; calyx lobes linear or linear-awl-shaped, unequal, the largest rarely equalling the tube; corolla an inch or less long, bright blue or bluish; funnel-form, spotted inside with white, the lobes ovate, acute, and spreading.

A showy species in damp open meadows in the lower valleys throughout the Rockies, especially abundant at Banff; flowering during August.

Annual, stems simple or branched, slender, erect, 6—20 inches high. Basal leaves obovate or spatulate, obtuse, narrowed into petioles; stem leaves ovate or lanceolate, acute, sessile, 3—5-nerved, 1—2 inches long, the uppermost smaller. Flowers ¼ of an inch or more long, few, on peduncles about their own length, in the axils of the upper leaves; corolla purplish-green or white, 4—5-parted, the lobes ovate, acute, each with a hollow deflexed or descending spur about half the length of the corolla.

In moist places and shaded slopes throughout the Rockies; a rather frequent but inconspicuous plant owing to its green colour; flowering in July.