Australian Tropical Rainforest Plants - Online edition

Youngia japonica (L.) DC.


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

Candolle, A.P. de (1838) Prodromus 7: 194.

Common name

Oriental false Hawksbeard; Japanese hawkweed

Stem

Annual herb up to 60 cm tall.

Leaves

Leaf blades 5-13.5 x 2.8-5 cm, surfaces of the leaf blade clothed in hairs more densely on the lower surface; petioles 1.2-3 cm long.

Flowers

Flower heads 3-4 mm diam., consisting of perfect flowers subtended by a single whorl of 5 bracts, each bract 2-2.5 mm long and a second row of 8 bracts each about 6 mm long. Calyx lobes, i.e. pappus, about 3 mm long. Corolla about 5 mm long, splitting along one side for about 3 mm. Anthers fused together, about 1 mm long, filaments about 1 mm long. Pollen yellow. Ovary about 1 mm long. Style + Stigma about 4 mm long. Ovule solitary.

Fruit

Achenes narrow-ellipsoid, 1.5-2 mm long with crowded ribs,ciliate, reddish to mid-brown. Pappus +/- 3 mm long, white.

Seedlings

Features not available.

Distribution and Ecology

An introduced species in NEQ, CEQ and southwards to south-eastern New South Wales. Altitudinal range from 12-917 m. Found in rainforest margins and along roads through sclerophyll forest.

Natural History & Notes

A weed of lawns, roadsides and orchards (Thompson 2007).

Synonyms
Prenanthes japonica L., Mantissa Plantarum 1: 107(1767).
RFK Code
4114
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