Recognize the problem
Asteraceae (daisy family)
names: Mexican sunflower, shrub sunflower, tree marigold.
Tournesol mexicain; Kinyarwanda: Icyicamahirwe; Chichewa:
or perennial herbaceous broadleaved shrub, woody at the base [2–3 (–5) m
high]; stems slightly ridged and hairy when young.
Greyish-green, finely hairy on underside giving a grey appearance; opposite
or alternate along the stem; simple, 3–5 (–7) pointed lobes (6–33 cm long and
5–22cm wide), margins with a series of curved projections or toothed.
Bright yellow, daisy or sunflower-like (up to 10 cm across), carried on long
and swollen stalks (7–30 cm long) which are velvety below the flowerhead.
Brown, small (4–8 mm long), dry, one-seeded, in a brown spiky mass.
As fodder, medicine, mulch, soil improvement, hedge/barrier, ornament and
possibly as a contaminant of seed.
By seeds and vegetatively, by producing roots from nodes on lower or
prostrate branches or clonal growth; wind and water, as well as human and
livestock movement can carry seeds over large distances.
Hedges around crop fields, fallow land, disturbed sites, wastelands, urban
open space, savannah, lowlands and riparian vegetation, roadsides.
Mexican sunflower has the ability to compete with agricultural crops,
particularly with rice and maize. Controlling T. diversifolia in crop fields can be highly costly to the farmer.
The plant also destroys grazing land for domestic animals. According to
reports, it is leading to the abandonment of farms in the Copperbelt region
of Zambia. The weed forms dense stands displacing native plant species and
the animals associated with them. It is
contributing to the extinction of local species, including important
medicinal plants. Mexican sunflower is also known to displace the invasive
and aggressive shrub Chromolaena
odorata, and is now considered to be one of the most invasive species in some