Australian Tropical Rainforest Plants - Online edition

Coleus scutellarioides (L.) Benth.


Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
© Barry Jago
Scale bar 10mm. © CSIRO
10th leaf stage. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
Family

Bentham, G. in Wallich, N. (1830), Plantae Asiaticae Rariores 2(5): 15.

Stem

Flowers and fruits as a herb or as a shrub about 1 m tall.

Leaves

Twigs 4-angled. Stems longitudinally grooved, +/- square in transverse section. Leaves variable in size and shape, blades about 1-15 (usually 4-7) x 1-10 (usually 3-5) cm. Stem, twigs, petioles and both the upper and lower surfaces of the leaf blade clothed in translucent hairs. Twigs marked by scars between the petiole bases resembling stipular scars. Numerous small, orbicular, yellowish glands visible on the underside of the leaf blade.

Flowers

Flower clusters usually pedunculate. Calyx about 2-2.5 mm long, with red or orange globular glands and hairs on the outer surface, lateral calyx lobes obtuse at the apex while the other calyx lobes are acute at the apex. Corolla tube geniculate near the base, usually about 8-13 mm long, 2-lipped, upper lip 4-lobed, corolla lobes with red or orange globular glands and hairs on the outer surface. Anthers +/- peltate on the filaments, usually with 1-4 red or orange globular glands near the point of attachment of the filament. Pollen white. Disk consists of a single tongue-shaped structure which towers over the ovary. The ovary appears apocarpous but each lobe lacks a style. Style inserted in the centre between the lobes of the ovary. Stigma 2-lobed or 2-lipped.

Fruit

Calyx persistent, outer surface clothed in reddish globular glands. Nutlets smooth when dry but produce short 'glandular' hairs when boiled in water. Nutlets small, about 0.9 x 0.7 mm and resemble seeds. Embryo minute. Cotyledons +/- sagittate at the base, cotyledons much wider than the radicle.

Seedlings

Cotyledons reniform (wider than long) about 4-6 x 6-10 mm, petioles about 4 mm long. First pair of leaves clothed in hairs on both the upper and lower surfaces, margin toothed. At the tenth leaf stage: leaf blade clothed in small yellowish glands on both the upper and lower surfaces. Petiole long and slender. Seed germination time 15 to 31 days.

Distribution and Ecology

Occurs in WA, NT, CYP, NEQ, CEQ and in south-eastern Queensland. . Altitudinal range from near sea level to 1000 m. Grows in monsoon forest, beach forest and in disturbed areas in rain forest. Also occurs in India, southern China, Taiwan, SE Asia, Malesia and the islands of the SW Pacific.

Synonyms

Ocimum scutellarioides L., Species Plantarum ed. 2 : 833(1762). Lectotype: Majana (alba et rubra) Rumphius, Herb. Amboin. 5: 291, t. 101. 1747, (lectotype: illustration designated by Merrill (Interpr. Rumph. Herb. Amboin.: 460 1917).  Plectranthus scutellarioides (L.) R.Br.Prodromus Florae Novae Hollandiae : 506 (1810).

RFK Code
3104
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