Australian Tropical Rainforest Plants - Online edition

Medicosma obovata T.G.Hartley

Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Flowers [not vouchered]. CC-BY: S. & A. Pearson.
Flower side view [not vouchered]. CC-BY: S. & A. Pearson.
Leaf glands from above [not vouchered]. CC-BY: S. & A. Pearson.
Inflorescence. CC-BY: ATH
Fruit and leaves. CC-BY: ATH
Leafy shoot. CC-BY: ATH

Hartley, T.G. (1985), A revision of the genus Medicosma (Rutaceae). Australian Journal of Botany 33(1): 39, figs 1 (map), 2c. Type: "QUEENSLAND. North Kennedy District: Mt Dryander, N. of Proserpine, W.T. Jones 3218, (CANB), vii.1967 (CANB, holotype)."


Shrub or small tree to 6 m high. Bark nondescript, blaze yellow-cream.


Leaves opposite or subopposite. Petiole 5-17 mm long, slightly swollen apically, near junction with leaf blade, glabrous. Leaf blade obovate, occasionally elliptic or oblong, 3.5-11 cm long, 1.5-6 cm wide, base obtuse to cuneate, margin entire, apex acute to obtuse, occasionally retuse. About 7-14 main lateral veins on each side of the midrib. Oil dots visible with hand lens and to the naked eye. Occasionally 1 or 2 (-4) flat circular glands on lower leaf surface.


Inflorescence axillary, solitary or few flowered, in fascicles or very reduced cymes. Pedicels nil or to 3 mm long. Flowers 5-7 mm long, white, sepals c. 2 mm long, petals free 4-10 mm long. Stamens eight, dimorphic, four long and four short. Anther filaments hairy, spiny glands present just below the anthers on the longer stamens. Disk shallowly 8 lobed. Ovary with 4 carpels more or less free, united on a common base and joined apically with a single style, style hairy towards the base; stigma capitate, 4-lobed.


Fruits consisting of 1-4 follicles united at base. Fruits broadly ovate to elliptic in outline (side view), floral parts often persistent in fruit. Follicle sub-obovoid 7 mm long, sparsely hairy at apex; epicarp thick, obliquely ribbed, green to brown; the endocarp a separate white cartilaginous layer, except for an area around the placenta which tears free and is membranous and persistent on seed. Seeds about 4 mm long, testa sparsely tuberculate and minutely papillate.


No features available.

Distribution and Ecology

Endemic to CEQ, restricted to the area around Mt Dryander. In rainforest and cloud forest to 820 m altitude.

Natural History & Notes
Medicosma obovata is very similar to Medicosma elliptica and Medicosma sessiliflora. From M. sessilifora it differs by the vein angle 50-60° in M. obovata and 70-80° in M. sessiliflora. From M. elliptica it differs by leaf shape, mostly obovate in M. obovata and usually elliptic to narrowly elliptic in M. elliptica.
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