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Scale bar 10mm. Copyright CSIRO
Leaf and flower. Copyright CSIRO
Flowers and immature fruit. Copyright CSIRO
Cotyledon stage, epigeal germination. Copyright CSIRO
10th leaf stage. Copyright CSIRO
Hyptis suaveolens (L.) Poit.
Poiteau, P.A. (1806) Annales du Museum National d'Histoire Naturelle 7: 472. Type: ?.
Ballota suaveolens L., Systema Naturae ed. 10: 1100(1759), Type: ?.
Mint Bush; Hyptis; Horehound; Wild Spikenard
Flowers and fruits as a herb but frequently grows into a shrub.
Leaf bearing twigs +/- 4-angled, twigs and leaves very aromatic when crushed. Leaf blades about 3-5 x 2-4 cm. Pale glands visible on both the upper and lower surfaces of the leaf blade. Septate hairs present on the upper surface of the leaf blade.
Inflorescence a 2-5-flowered cyme on peduncles which are usually longer than the petioles. Calyx about 5-5.5 mm long, lobes linear, all parts of the outer surface of the calyx clothed in long white hairs and short glandular hairs or spherical hyaline stalked glands. Corolla about 4-5 mm long, outer surface clothed in white hairs. Anthers pink, red or purple, borne obliquely on the filaments, filaments hairy. Style glabrous, inserted in the centre between the lobes of the ovary.
Fruit resembles a capsule but actually consists of a persistent ribbed calyx about 8-10 mm long and contains 1-4 nutlets. Nutlets flattened, narrowly oblong, about 1.2-4 mm long. Nutlet surface +/- smooth when dry but producing a dense mass of fine white hairs when boiled in water.
Cotyledons about 9-12 x 7-11 mm, purple on the underside, petiole slightly shorter than the cotyledon blade. Stout septate hairs present on the upper surface of the first pair of leaves. At the tenth leaf stage: leaf blade about 30-35 x 25-30 mm, stout septate and fine simple hairs present on the upper surface.
Distribution and Ecology
An introduced species originally from tropical America but now pantropic, which has become naturalized in WA, NT, CYP, NEQ and southwards as far as south-eastern Queensland. Altitudinal range from near sea level to 750 m. Usually grows on heavily grazed open forest areas but also found in monsoon forest and vine thickets.
This species may have medicinal properties. (http://squid2.laughingsquid.net/hosts/herbweb.com /herbage/A13720.htm)
Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)