Species information Abo ut Reso urces Hom e

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z pilosa Click on images to enlarge

Family Scientific Name Bidens pilosa L. Linnaeus, C. von (1753) Species Plantarum 2: 832. Type: Habitat in America.

Common name Flowers. Copyright R.L. Barrett Spanish Needles; Beggar Ticks; Pitchforks; Cobbler's Pegs; Blackjack Weed * Stem Annual herb, but occasionally grows into a shrub 1.7 m tall. Flowers. Copyright R.L. Barrett or leaflet blades about 6-12 x 4-8 cm, only sparsely hairy on the underside, usually trifoliate or pinnate, occasionally simple. Petioles grooved on the upper surface, bases forming a transverse ridge across the twig and this ridge resembles a stipular scar. Stems +/- 4-angled. Flowers Flowers borne in heads about 5-15 mm diam., about 40-50 flowers per head. Flowers surrounded or subtended by persistent erect bracts with fimbriate margins. Pollen orange.

Fruit Seeds. Copyright R.L. Barrett Each fruit or nutlet about 6-12 mm long, ending in about 3-5 plumes each with downward pointing hairs which adhere to clothes, animal fur, etc. Cotyledons longer than the radicle but of equal width. Seedlings Cotyledons +/- linear, about 13-22 x 2-4 mm. First pair of leaves either simple or deeply lobed or compound with three leaflets each of which is toothed or lobed. At the tenth leaf stage: leaves trifoliolate with the middle leaflet much longer than the lateral leaflets. Leaflets hairy on both the upper and lower surfaces. Seed germination time 12 to 33 days. Seed. Copyright R.L. Barrett Distribution and Ecology A cosmopolitan species of uncertain origin, now naturalised in WA, NT, CYP, NEQ, CEQ and southwards as far as Victoria. Altitudinal range from near sea level to 1200 m. Grows in disturbed areas in rain forest. Natural History & Notes Two varieties occur, see Flora of 37:460-462. This species has medicinal uses. An infusion of the , sometimes of the flower-heads only, has been used in domestic medicine in several countries for diarrhoea, dysentery and coughs; the tannin content provides an astringency which would be of some use in those complaints. Cribb (1981). Habit, leaves, flowers and fruit. Copyright CSIRO Herb (herbaceous or woody, under 1 m tall) X Shrub (woody or herbaceous, 1-6 m tall) X Synonyms Bidens pilosa var. typica Domin, Bibliotheca Botanica 89(4): 1235(1928). RFK Code 3422 CC-BY Australian Tropical Herbarium unless otherwise indicated in the images.

10th leaf stage. Copyright CSIRO

Cotyledon stage, epigeal germination. Copyright CSIRO

Scale bar 10mm. Copyright CSIRO