Australian Tropical Rainforest Plants - Online edition

Coleus thalassoscopicus (P.I.Forst.) P.I.Forst.

Herb (herbaceous or woody, under 1 m tall)
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Herbarium specimen. © CSIRO

Paton, A.J. et al (2019) Phytokeys 129: 105.


Subshrub up to 60 cm tall; foliage slightly aromatic when crushed; plant covered in scattered glandular trichomes, sessile glands orange. Stems square in cross-section, semi-erect to straggling, succulent.


Leaves discolorous; petioles 10-35 mm long; lamina narrow-ovate to ovate, succulent, 20-100 x 14-80 mm, crenate with 13-14 teeth up to 4 mm long; apex acute; base rounded to truncate; upper surface grey-green with impressed veins; lower surface pale green with raised veins and orange-coloured sessile glands dense.


Inflorescence up to 35 cm long, 1-5 branched from near the base; verticillasters 8-14 -flowered, up to 17 mm apart; pedicels 3-4 mm long; cymes sessile; bracts triangular-ovate, 2.2-2.4 x 2.2- 2.5 mm. Flowering calyx 2.8-3 mm long, fruiting calyx larger, lateral lobes lanceolate; lower lobes lanceolate-falcate. Corolla 9-11 mm long and lilac coloured; tube 4.5-5 mm long, curved at 90-100 degrees 2-2.3 mm from base and slightly inflated upwards, glabrous; the upper orbicular lobes erect to recurved, lateral lobes oblong and glabrous; lower lobe ovate, 5-6 x 4-5.5 mm. Filaments 7-9 mm long, lilac, fused for 4-4.5 mm from base. Style lilac and 7-9 mm long.


Nutlets +/- circular in outline, somewhat flattened, 0.9-1 mm long and wide, glossy brown, smooth.


Features not available.

Distribution and Ecology

Only known from the type locality, Bell Peak, near Gordonvale in NEQ. Altitudinal range from 990-1000 m. In rainforest margin and moss-fern thicket on granite outcrops.

Plectranthus thalassoscopicus P.I.Forst.Austrobaileya 4(4): 653 (1997). Type: Queensland: Cook District: North Bell Peak summit area, Malbon Thompson Range, 17 deg 05 min S, 145 deg 52 min E, 12 Nov 1995, P.I.Forster 18048, R.L.Jago & R.Jensen (holo: BRI [2 sheets]; iso: K, MEL, QRS).
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