Australian Tropical Rainforest Plants - Online edition

Mesosphaerum pectinatum (L.) Kuntze


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

Kuntze, C.E.O. (1891) Revisio Generum Plantarum 2: 525.

Common name

Comb hyptis; Hyptis, Comb

Stem

Usually flowers and fruits as an erect herb but may reach 4 m.

Leaves

Leaf bearing twigs +/- 4-angled, twigs and leaves aromatic or not aromatic when crushed. Leaf blades about 2-8 x 1-4.5 cm. Hairy on both leaf surfaces, usually denser on underside.

Flowers

Inflorescence a 6-15-flowered cyme. Calyx about 2.5 mm long, 10-ribbed, lobes linear, all parts of the outer surface of the calyx clothed in hairs. Corolla white to pale blue or pink-tinged, 3-3.5 mm long.

Fruit

Fruit resembles a capsule but actually consists of a persistent ribbed calyx about 8-10 mm long and contains 1-4 nutlets. Nutlets oblong, to 2 mm long. Nutlet surface smooth when dry.

Seedlings

Cotyledons about 3-5 x 4-6 mm, reniform. First pair of leaves opposite, margins crenate with about 3-5 teeth, upper and lower surfaces of the leaf blade hairy. At the tenth leaf stage: crushed plant parts emit an odour like that of mint (Mentha sp.) leaf margin irregularly serrate. Leaf petiolate. Stem square in transverse section.

Distribution and Ecology

An introduced species originally from tropical America, which has become naturalised in NEQ and CEQ. Altitudinal range near sea level. Usually grows along roadsides, under powerlines and other disturbed areas.

Natural History & Notes

A serious tropical weed.

Synonyms

Hyptis pectinata (L.) Poit., Ann. Mus. Par., vii: 474 (1806). Nepeta pectinata L., Systema Naturae Edn. 10, 2: 1097 (1759), Type: Browne s.n., Jamaica.

RFK Code
3570
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