Ageratum
L.
Annual or perennial herbs. Leaves alternate or opposite, deltoid-ovate, elliptic or
lanceolate, entire, dentate or shallowly lobed. Heads discoid, many flowered. Involucral
bracts many, lanceolate, glabrous or pilose. Corolla lobes 5, papillose within. Anthers
appendaged. Style appendages linear, usually dense papillose. Achenes 4 - 5 angled,
glabrous or bristly on the ribs. Pappus of 4 - 5 scales, flattened at base.
All warmer countries; ca 45 species, 2 in India.
Literature. JOHNSON, M.F. (1971). A monograph of the genus Ageratum L. (Compositae- Eupatorleae) Ann. Miss. Bot. Gard. 58: 6 - 88.
All warmer countries; ca 45 species, 2 in India.
Literature. JOHNSON, M.F. (1971). A monograph of the genus Ageratum L. (Compositae- Eupatorleae) Ann. Miss. Bot. Gard. 58: 6 - 88.
KEY TO THE SPECIES
| 1a. Involueral bracts glabrous; corolla shorter than the awned pappus scales | 1. Ageratum conyzoides |
| b. Involucral bracts pilose without; corolla as long as or longer than the awned pappus scales | 2. Ageratum houstonianum |
