Eggleaf or Chihuahua gentian

Gentiana microcalyx Lemmon, Pacific Rural Press 23: 129. 1882

Herbs annual, 15–60 cm. Stems decumbent to erect, branched distally, often also at or near base. Leaves: basal often withered by flowering, larger leaves ± petiolate, blades elliptic to spatulate or oblanceolate, 10–25 × 2–8 mm; cauline blades cordate-ovate to lanceolate, 5–50 × 3–30 mm. Inflorescences terminal and often axillary umbelloid cymes; pedicels 3–25 mm. Flowers (4- or)5-merous; calyx 2–3(–5) mm, lobes tri­angular to oblong or elliptic, ± unequal, 1.5–3.5 mm; corolla yellowish white to pale rose-violet or pale violet-blue, occasionally with red-violet spots distally, narrowly funnelform to nearly salverform, 6–13 mm, lobes spreading, lanceolate-ovate, (2.5–)3–6.5 mm, apex obtuse to acute (in dried specimens sometimes appearing ± acuminate through inrolling), without adaxial scales or fringes; ovary short-stipitate.

Flowering late summer–fall. Moist, rocky sites in ± open pine and pine-oak woods; 600–2100 m; Ariz.; Mexico (Chihuahua, Coahuila, Durango, Sonora).

Gentianella microcalyx is primarily of Mexican dis­tribution, where its range extends to higher elevations than in the flora area, where it is known only from southern Arizona.