Flora of New Zealand Series

square-stemmed St John's wort

Glabrous perennial herb with slender stolons; flowering stems erect, to 1 m tall, stout and woody at base, 4-angled with angles winged, with scattered black glands. Lvs sessile, 1-3.5 × 0.5-1.8 cm, elliptic to ovate or obovate, with pellucid glands beneath and sometimes sparse intramarginal black glands; longitudinal nerves 5-9; base ± amplexicaul; apex obtuse or rounded. Infl. terminal, a panicle of cymes, dense, many-flowered. Sepals equal, c. 4-5 mm long, narrow-lanceolate to lanceolate-elliptic, not accrescent, entire, with black glands sometimes sparse but usually 0; apex acuminate. Corolla 1-2 cm diam., pale yellow; petals elliptic-ovate, > sepals; black glands usually 0. Stamens in 3 bundles, < or nearly = petals. Styles 3, = ovary. Capsule 5-8 mm long, oblong or oblong-ovoid, dry. Seeds 0.7-0.9 mm long, cylindric, finely reticulate.

N.: Waiaua R. (Opotiki District), Akatarawa Valley (near Paraparaumu), Abbot's Creek (Wairarapa); S.: Christchurch.

Europe, W. Asia, N. Africa 1940

Local in swampy places.

FL Dec-Feb.

H. tetrapterum has been previously known in N.Z. as H. acutum and H. quadrangulum.