Comastoma tenellum

Slender Gentian is a small, glabrous, annual herb which stands 2-15 cm tall; Montana collections are on the small end of this range. The stems are 4-angled and may be branched; those of small plants are often unbranched. There are usually several spoon-shaped basal leaves which are 3-10 mm long, and few, if any, slightly larger, opposite stem leaves, which are 5-15 mm long. There are one to a few flowers per stem borne singly on long pedicels; stems of small plants are often reduced to single, flowered, leafless scapes. The flowers have 4 green sepals which are about half as long as the corolla. The white to bluish-purple corolla is 8-15 mm long and is tubular-shaped with 4 terminal lobes which are about one-third as long as the tube; the inner surface of each lobe has two fringed scales near its base. There are 4 stamens attached to the inside of the corolla tube and a single basal pistil.

This species is distinguished from other Montana GENTIANELLA by having flowers borne on long pedicels in an open inflorescence (in small plants, these are reduced to leafless scapes) with 4 distinct sepals and corolla lobes with fringed scales. Species of GENTIANA differ by having corollas which are plicate.

This species is found in wet, open areas (Wildflower Center, 2021).