Australian Tropical Rainforest Plants - Online edition

Hypericum gramineum G.Forst.

Herb (herbaceous or woody, under 1 m tall)
Click/tap on images to enlarge
Flowers. © Australian Plant Image Index (APII). Photographer: M. Fagg.
Fruit [not vouchered]. J.L. Dowe
Herbarium specimen. © DERM

Forster, J.G. (1786) Florulae Insularum Australium Prodromus : 53. Type: Nova Caledonia.

Common name

Small St. John's Wort


Plant up to 30 cm tall. Stems solitary or ± cespitose, unbranched below inflorescence or variously branched. Stems 4-lined.


Leaf blades about 8-17 x 3-7 mm, thickly papery, abaxially paler and sometimes glaucous; petioles nil, base of the leaf blade clasping the stem. Oil dots clearly visible with a lens, intramarginal glands dense; floral leaves stem-clasping.


Terminal cymes usually with 3 or more flowers, rarely flowers solitary and axillary; bracts and bracteoles triangular-lanceolate to linear; flowers 5-12 mm diam.; pedicels erect, 5-15 mm long. Sepals erect, lanceolate to narrowly elliptic, subequal to unequal, 2.8-5[-9] × [0.8-]1.5-2 mm, apex acute to subacute, veins 3-5; petals Petals obovate to oblanceolate, 5-10 × 2-5 mm, about. 1.3 × as long as sepals; laminar glands few. Stamens 20-50, mostly free, persistent; ovary narrowly ovoid-conic; styles 3, 0.7-1.8 mm, ca. 0.9 × as long as ovary, ± spreading.


Capsule 3-valved, ovoid-conic, 2.5-8 × 1-3.5 mm, about 2 × as long as the persistent sepals and with persistent styles. Seeds brown,about 0.5 mm; testa finely ribbed with transverse lines.


Features not available.

Distribution and Ecology

Widespread across Australia, and occurs in WA, NT, CYP, NEQ and CEQ. Altitudinal range from sea level to 1010 m. Grows in rainforest margins and openings in forest, open Eucalypt forest, open Melaleuca forest, open Eucalypt woodland, heathland and in wooded grassland. Also occurs in Bhutan, NE India, Papua New Guinea, Vietnam and Pacific islands (Hawaii, New Caledonia, New Zealand).

Natural History & Notes

Causes photosensitization and enteritis (Webb 1948).

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