Catesby’s or coastal plain gentian

Dasystephana parvifolia (Chapman) Small; Gentiana catesbaei var. nummulariifolia Fernald; G. elliottii Chapman

Herbs perennial, 1–7 dm, usu­ally puberulent on stems only, occasionally glabrous. Stems 1–5, terminal from caudex, erect or nearly so. Leaves cauline, ± evenly spaced; blade usually ovate, occasionally elliptic, 1.5–7.5 cm × 4–30 mm, apex acute. Inflorescences ± dense 1–10-flowered cymes or heads, sometimes with additional flowers at 1–4(–8) nodes or on branches. Flowers: calyx 17–55 mm, lobes erect, lanceolate, 10–35 mm, mostly longer than tube, often ± foliaceous, margins ciliate; corolla blue or occasionally rose-violet, tubular, slightly to fully but narrowly open, 35–55 mm, lobes ± erect to spreading, deltate-ovate, 5–10 mm, usually 2–4 mm longer than plicae, free portions of plicae divided 1/2 or more of their length into 2 subequal, erect, ± triangular, lacerate segments; anthers connate. Seeds winged.

Flowering fall(–winter in Fla.). Moist ± open woods, clearings, roadsides; 0–100 m; Del., Fla., Ga., Md., N.C., S.C., Va.

Gentiana catesbaei is believed to be extirpated from New Jersey and Pennsylvania. Specimens from Alabama have been reidentified as G. saponaria as all such spec­imens seen in studies for this flora had the elliptic leaves and short calyx lobes typical of G. saponaria rather than the ovate leaves and much longer calyx lobes that characterize G. catesbaei.

From the more widely distributed Gentiana saponaria, G. catesbaei differs most conspicuously in its ovate rather than elliptic leaves, widest proximal to rather than near mid-length; calyx lobes widest near mid-length and usually 1.5–3 times as long as the tube; and generally with spreading rather than incurved corolla lobes.

Gentiana catesbaei is almost entirely restricted to the Atlantic coastal plain, where it displaces the closely related G. saponaria south of northeastern North Carolina. In the northern part of its range, where the ranges of these species overlap, they generally remain distinct, although a few plants apparently of hybrid origin have been found. A hybrid with the much less similar G. villosa is also known.