Description

Key Characters:

Growth Form: Shrubs or trees, 1–6 m tall, terrestrial or rarely epiphytic.

Stems: Stems branched repeatedly, spreading, light gray or light brown, glabrous or rarely pubescent, with numerous helically arranged leaf scars near apex, pith solid, latex white, viscous.

Roots:

Leaves: Leaves simple. Alternate. Blades elliptic 6.3–9.5 cm long, 2.3–3.8 cm wide. Apex acute. Base cuneate. Lower surfaces pubescent, especially along midrib. Margins callose crenulate, rarely callose–serrulate. Petioles 1.8–2.5 cm long, glabrous. Stipules absent.

Flowers: Flowers in inflorescences 2–flowered, glabrous; peduncle 4.4–4.6 cm long, pendent; pedicels 5.8–6.2 cm long, pendent. Flowers bisexual (perfect), epigynous, zygomorphic, resupinate, protandrous. Hypanthium obovoid, 1.5–1.6 cm long, 1.9–2 cm in diameter, glabrous. Calyx synsepalous; tube adnate to the ovary, forming a hypanthium, hemispheric, obconic, obovoid, turbinate, or rarely oblong, smooth or with 10 longitudinal furrows, rarely muricate or with 10 longitudinal ridges; lobes 5, valvate, either less than 1⁄2 as long as the corolla, distinct or rarely connate at base, persistent, triangular or deltate, rarely oblong or ovate, firm, green, or as long as the corolla (rarely only ⅔ as long), connate for 1/5–⅘ their length, deciduous, mimicking the corolla in shape, texture, and color. Perianth 7.8–8.5 cm long, green, purple, maroon, or rose, often longitudinally striped, the calyx lobes almost equalling the corolla; tube 4.6–5.5 cm long, 1.4–2 cm in diameter, arcuate, narrower at middle than at base; lobes 2.2–3 cm long, 3–5.5 mm wide, suberect or slightly spreading. Stamens 5, syngenesious, alternate with the corolla lobes, included or exserted; anthers connate, dithecal, opening introrsely by longitudinal slits, purple or white, the 3 dorsal ones a little longer than the 2 ventral ones, the latter with tufts of stiff white trichomes at apex, otherwise glabrous, or sometimes pubescent along the sutures, rarely so on the surfaces; anther tube 1.1–1.3 cm long, 3–4 mm in diameter; filaments 8–8.6 cm long, connate above, free from the corolla, purple, magenta, or white, glabrous. Pollen tricolporate, prolate, ellipsoidal. Ovary inferior, 2-carpellate, 2-loculed; ovule placentation axile, placentae large; style slender, terete (cylindrical), with a ring of stiff white hairs near apex; stigma 2-lobed, the lobes appressed and non–receptive as the style grows through the anther tube, pushing out pollen, after which the stigmas spread and become receptive.

Fruit: Berries unknown. Seeds numerous; tiny; dark brown or black; minutely foveate–reticulate; shiny; with a straight; short to spatulate dicotyledonous embryo embedded in oily endosperm.

Ploidy:

Habitat: On the windward slopes of Haleakalā; montane cloud forest.

Elevation Range: ca. 1,645 m.