Plants 40–110 mm tall. Root 3.1 mm diam. at caudex base. Caudex 30–80 mm long. Flowering stems 3–26 per plant, the largest 1.8–2.3 mm diam. at base, 0.7–1.3(–1.7) mm diam. when dry, green or purple-black; stem leaves 6–13 pairs per stem. Leaf rosette absent. Leaves narrowly to very narrowly elliptic or obovate, (8.6–)11.0–16.0(–25) mm long, 1.1–3.9 mm wide, purple at the base, flat or slightly V-shaped, margins minutely toothed or smooth; leaf 0.9–1.4 mm wide at leaf base; apex rounded to acute. Pedicels (0–)3–18 mm long, 0.9–1.0 mm diam., 0.52–1.0 mm diam. when dry. Flowers 6–52 per plant, 10–20 mm long. Calyx 5.2– 7.1 mm long; lobes 3.5–5.4 mm long, 1.1–1.7 mm wide at base, green, plane or recurved, lobe margins minutely toothed, hairs at calyx–corolla fusion line present or absent, sinus hairs absent or sparse. Corolla 9.2–15.2 mm long, white, usually with violet tinting on the outside and sometimes inside of the corolla lobe apices, tube 3.0–5.2 mm long; lobes 6.2–10.0 mm long, 3.9–6.7 mm wide, toothed only at the apices, margins very fi nely serrulate or smooth; hairs below sinus absent or present; nectary 1.2–4.3 mm from corolla base, V-shaped with a pocket or with fl aps that are not joined at the base, pocket margins toothed or untoothed. Filaments 4.0–8.6 mm long from corolla base, 0.3–0.6 mm wide. Anthers 1.1–2.0 mm long, anther wall blueblack. Ovules 13–28 per ovary. Capsule 7.6–15 mm long. FL Mar–Jun(–Oct).

Ab subspeciei astonii nectario marsupiformi margine libera dentata similis, sed foliis minoribus, (8.6–)11.0–16.0(–25) mm (non 16–32 mm) longis, ad apices latioribus: 2.7–3.9 mm latis, antheris brevioribus 1.1–2.0 mm (non 1.7–2.5 mm) longis, ovulis paucioribus, 13–28 per ovarium (non 27–30) differt.