Ageratum conyzoides L
Diagnostic description:
Ageratum conyzoides L
Habit: Annual,aromatic herb with 30-60cm long,hispid hairy branches
Leaves: Leaves with 0.3-5cm long hairy petiole;blade ovate , acute, truncate to cordate at base,serrate,2-5×1.5-3cm
Inflorescences: Capitula small, 4-6mm across, 7-16 in terminal corymbs , involucre campanulate, 3 mm across; the bracts 2-3-seriate,linear-laceolate or oblanceolate , 1-3×0.5-2 mm,hairy on the margin or at least above , acuminate
Florets: all tubular, numerous,c. 50-75, bluish or White, 1-1.5mm long
Fruits: Achenes Black ,5 angled, 2×0.5 mm , pappus of 5 equal scaly bristles, as long as achenes , dilated at base, scabrous
Distribution : Pantropical , originally from tropical america
Taxonomic name: