Ourisia vulcanica

Detailed description

Perennial herbs 60-170 mm tall, with erect inflorescences and flat to ascending leaves; stems 2.6-5.8 mm diameter; internodes 3.6-7.3 mm long, scarcely discernible because of tight clustering of leaves, glabrous. Leaves tightly tufted at terminus of stem or in subrosettes or opposite; petiole 3.0-22.0 x 0.7-5.2 mm, sparsely to densely eglandular villous on the margins only; lamina 6.9-26.8 x 4.7-20.1 mm, narrowly to broadly ovate, apex subacute, bases cuneate, margin regularly crenate, upper surface glabrescent, hairs sparse, eglandular, on proximal margins, undersides punctate. Inflorescence racemose, 66-177 mm long, bracteate, with 1-4 flowering nodes per inflorescence, 2-3 bracts and 1-3 flowers per node and c.1-8 flowers per raceme; peduncle 0.7-2.0 mm diameter, eglandular pilose. Floral bracts 9.4-19.4 x 3.4-9.4 mm, becoming smaller toward apex, sessile, narrowly lanceolate to narrowly ovate, rarely ovate, in proximal bracts margin with a few irregular, round teeth on the distal third to half of lamina, in distal bracts margin subentire to entire, glabrous or pilose on margins only, hairs eglandular, 0.4-0.8 mm long. Flowers 12.6-15.9 x 9.2-16.6 mm; pedicel 5.9-25.4 mm long, sparsely to densely pilose, hairs up to 1.1. mm long, eglandular, rarely mixed with short, glandular hairs near calyx base. Calyx 5.6-8.6 x 5.7-8.2 mm, irregular, externally glabrous or with isolated eglandular hairs to 0.7 mm long near base only, internally glabrous, margin ciliate, with isolated to densely distributed eglandular hairs to 0.7 mm long; anterior calyx lobes 5.1-7.6 x 1.6-2.9 mm, posterior calyx lobes 2.6-4.5 x 1.4-2.4 mm, 3 posterior calyx lobes divided 1/4-1/2 of length, 2 anterior lobes divided almost to base, lanceolate to narrowly ovate, elliptic, slightly tapering to a rounded or sometimes subtruncate apex bearing a hydathode, undersides 3-veined. Corolla 11.7-15.6 x 16.4-19.9 mm when flat, bilabiate, tubular-funnelform, white, sometimes flushed red, glabrous or externally bearing isolated, eglandular hairs near base of corolla lobes; tube 5.4-9.4 x 5.3-7.6 mm at apex, 2.3-2.7 mm wide at base, not constricted near base, yellow inside with 3 lines of hairs extending to the corolla lobes and forming a ring around the corolla tube mouth; anterior corolla lobes 5.1-8.2 x 3.8-6.1 mm at widest point, 2.4-3.6 mm wide at base, posterior lobes 4.0-6.2 x 3.6-5.7 mm wide at widest point, 3.1-3.8 mm wide at base, widely spreading, obovate-spathulate, obcordate, apex plane or slightly emarginate. Stamens 4, didynamous; comprising two long stamens 8.2-11.5 mm long, exserted, or rarely only reaching tube opening, and two short stamens 6.5-9.9 mm long, reaching tube opening or exserted; anthers 0.7-1.2 x 0.8-1.4, reniform to horseshoe-shaped; staminode c.0.5 mm long inserted 0.3 mm above base of corolla, or absent, Style 6.0-7.4 mm long, straight, exserted; stigma 0.4-0.9 mm diameter, emarginate; ovary 2.5-4.0 x 1.6-2.0 mm, c.4.2 mm diameter, glabrous. Capsule 5.6 x 4.2 mm, glabrous with loculicidal dehiscence; fruiting pedicels 22.5-29.8 mm long. Seeds 0.7-0.9 x 0.3-0.5 mm.