Australian Tropical Rainforest Plants - Online edition

Coleus gratus (S.T.Blake) P.I.Forst. & T.C.Wilson


Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
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Scale bar 10mm. © CSIRO
10th leaf stage. © CSIRO
Family

Paton, A.J. et al (2019) Phytokeys 129: 53.

Stem

Usually flowers and fruits as a shrub about 1 m tall, occasionally flowers when much smaller.

Leaves

Leaf blades about 2.5-5 x 1.5-3.5 cm, petioles about 1.5 cm long, margin crenate. Both the upper and lower surfaces of the leaf blade densely clothed in matted pale-coloured hairs. Reddish glands present on the lower surface of the leaf blade but very difficult to see because of the dense covering of hair. Crushed leaves emit very little or no odour.

Flowers

Racemes about 10-30 cm long. Clusters about 10-20-flowered and about 7-13 mm apart. Pedicels about 2.5-5 mm long. Calyx about 2.3-3.3 mm long with sessile, orange glands on the outer surface. Corolla about 7-11 mm long with sessile, reddish glands on all lobes. Base of the ovary surrounded by a single large gland, style one, stigmas two.

Fruit

Fruiting calyx about 3.5-4.75 mm long. Nutlets nearly orbicular, about 0.8-0.9 mm diam., located at the base of the fruiting calyx.

Seedlings

Cotyledons reniform, wider than long, about 5-6 x 7-9 mm, venation not apparent. First pair of leaves hairy on both the upper and lower surfaces, margin sparsely toothed. At the tenth leaf stage: leaf blade margin crenate, lateral veins 4 or 5 on each side of the midrib, both the upper and lower surfaces hairy. Stem 4-angled.

Distribution and Ecology

Endemic to NEQ, known only from collections made in the Walsh's Pyramid and Gillies Highway areas. Altitudinal range from 100-600 m. Grows in rocky areas, usually in open forest but sometimes in similar situations in rain forest.

Synonyms
Plectranthus gratus S.T.Blake, Contributions from the Queensland Herbarium 9: 49 (1971). Type: Australia, Queensland, Walsh’s Pyramid (Cultivated at The Gap), 10 Jan. 1960, S.T. Blake 21192 (holotype: BRI).
RFK Code
3348
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