Corolla funnel-form or campanulate; without glands, spurs or scales. =Gentiana.= Corolla campanulate; spurred at the base. =Tetragonanthus.= [Sidenote: =Gentiana acuta= Michx. _Northern Gentian._] 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. [Sidenote: =Gentiana propinqua= Richards. _Four-parted Gentian._] 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. [Sidenote: =Gentiana prostrata= Haenke. _Dwarf Gentian._] 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. [Sidenote: =Gentiana glauca= _Pale-glaucous Gentian._] 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. [Sidenote: =Gentiana affinis= Griseb. _Large Gentian._]