Australian Tropical Rainforest Plants - Online edition

Bidens alba var. radiata (Sch.Bip.) F.Ballard ex Melchert


Weed
Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
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Flowers. © CSIRO
Family

Melchert, T.E. (1975) Phytologia 32(4): 295.

Common name

Shepherd's Needles; Spanish Needles

Stem

Herb to shrub 60-200 cm tall. Stems 4-angled.

Leaves

Petioles 3-3.5 cm long, narrowly winged with hairs on the edge. Leaves simple or trifoliolate; simple leaf blades 7.3-8.5 x 4 cm, leaf blades on compound leaves 3-5-10 x 2.2-4.5 cm, leaflet stalks 3-20 cm long.

Flowers

Inflorescence about 2.5 cm diam., flowers subtended by bracts about 4 mm long. Ray florets: About 5 per inflorescence, main lobe 8-veined, white, about 10 x 9, 2-3 -lobed but tubular at the base. Anthers nil. Ovary nil. Disk florets: Flowers 2-3 mm diam. Calyx, i.e. pappus, about 2 mm long. Corolla tube 2-5 mm long, lobes about 1 mm long. Anthers fused together, about 2 mm long, filaments about 3 mm long. Pollen orange-yellow. Ovary about 2 mm long, ovule solitary. Style about 5 mm long. Stigma hairy, about 2 mm long.

Fruit

Fruits 9-12 mm long including the 2-barbed pappus, hairs or trichomes. Each fruit subtended by a bract about 6 mm long. Embryo white, 6-9 mm long, consisting mainly of cotyledons. Cotyledons about 4 mm long. Radicle about 3 mm long.

Seedlings

Features not available.

Distribution and Ecology

An introduced weed originally from tropical America, now naturalised in NEQ,CEQ and south into south eastern Queensland and north eastern New South Wales. Altitudinal range from 3-900 m. Found in edges of rainforest, in open forest and notophyll vine forest, woodland and in grassland.

Synonyms
Bidens pilosa f. radiata Sch.Bip., Histoire Naturelle des Iles Canaries 3: 242(1844), Type: Canary Isl. In aquosis et ad fossas insularum Canariensium vulgaris: Webb!; habeo e Madera: Webb!.
RFK Code
4024
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