Blackstonia perfoliata (L.) Huds.

Stems 15–55 cm tall, somewhat angular above, simple or branched in upper part. Lvs 7.5–25 × 4–15 mm, ovate or oblong-ovate, glaucous; base of cauline lvs broad and cordate; apex acute. Cymes loose, few- to many-flowered. Pedicels slender, to c. 4 cm long, sometimes a few fls almost sessile. Calyx 8–12 mm long, lobed nearly to base; lobes acuminate. Corolla 10–15 mm long, bright yellow; lobes 6–9, lanceolate-oblong, patent, closing at night. Stamens as many as corolla lobes; anthers narrow-linear, = filaments. Stigmatic lobes erect at anthesis, later spreading. Capsule c. 1 cm long, ellipsoid. Seeds numerous, < 0.5 mm long, reticulate.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

Flowering: Dec.–Feb.