Australian Tropical Rainforest Plants - Online edition

Sigesbeckia orientalis L.


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

Linnaeus, C. von (1753) Species Plantarum 2: 900. Type: Habitat in China, Media ad pagos.

Common name

Indian Weed; Farmer's Lice

Stem

Usually flowers and fruits as a shrub about 1 m tall but also flowers when smaller.

Leaves

Leaves variable, leaf blades up to 6 x 3-3.5 cm, lower surface clothed in numerous small yellow glands. Lateral veins forming loops well inside the blade margin. Both the upper and lower surfaces of the leaf blade hairy. Twigs marked by scars resembling stipular scars. Stems hollow, pith absent.

Flowers

Flowers sessile in heads, about 15 flowers per head. Each head of flowers usually contains some female flowers, each consisting of a +/- 3-lobed perianth, and some hermaphrodite flowers with a 5-lobed perianth tube enclosing five anthers fused into a tube. Each head subtended by an involucre of about five green spathulate bracts which are clothed in sticky glands. Outer bracts about 5-10 x 0.5 mm. Corolla orange or yellow in the upper half but green in the lower half. Ovary glabrous.

Fruit

Disk achenes 4-angular, about 2-5 mm long. Ray achenes clasped by persistent glandular hairy bracts.

Seedlings

Hypocotyl clothed in short erect hairs just visible with a lens. Stem above the cotyledons clothed in much longer erect white hairs. Cotyledons +/- orbicular, about 6-7 x 5-6 mm. First pair of leaves with toothed margins. At the tenth leaf stage: stem, terminal bud and both the upper and lower leaf blade surfaces clothed in white somewhat scabrous hairs. Leaf blade margins irregularly toothed and/or lobed. Seed germination time 10 to 32 days.

Distribution and Ecology

Probably an introduced species from Asia and Africa. Occurs in CYP, NEQ, CEQ and southwards as far as Victoria. Also found in Western Australia and South Australia. Altitudinal range in NEQ from near sea level to 1100 m. Grows in clearings and along roads in monsoon forest, vine thickets and rain forest.

Natural History & Notes

This species may have some minor medicinal uses. (http://www.mylifechoices.com/dictionary.shtml)

The plant is a common weed in China and has been used there in herbal medicine both externally for ulcers and boils and internally for malaria and rheumatism and as an analgesic. Cribb (1981).

RFK Code
3412
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