Bidens frondosa, an annual herb originating in North
America, occurs in damp wastelands or roadsides in various
districts. Dark purple stems with four ridges grow to 0.5-1.5cm in
height. Leaves with long petioles have opposite phyllotaxis; the
lower parts are biternate compounds, and those on the upper ones are
ternate compound leaves. The leaflets all have petiolules,
3-13cm-long oval-like lanceolates, with tips pointed and margins
with serrations. Flower heads are yellow and set themselves singly
on branch tips. Involucral bracts are 6-12 in number and
significantly large and conspicuous. Bloom time: September-October. |