Eupatorium
L.
Herbs or shrubs. Leaves usually opposite, rarely alternate, entire or serrate. Heads
homogamous, corymbose or paniculate, few-many flowered. Involucral bracts 1 - 5 seriate,
equal or unequal. Corolla tubular; limb 5-lobed or toothed. Anthers appendiculate at tip,
base usually obtuse. Style branches usually long, pubescent, papillose. Achenes 4 - 5
angular, glandular or eglandular, glabrous or hairy on the ribs. Pappus hairs uniseriate,
capillary, scabrous.
Distributed in Europe, Asia, Africa but chiefly in Mexico, West Indies and Tropical S. America; ca 1200 species, 10 in India.
Literature. BENNETT, F.D. & V.P. RAO (1968). Distribution of an Introduced weed Eupatorium odoratum L. (comp.) in Asia & Africa and Possibilities of its Biological Control. PANS 14(3): 227 - 281. GRANT, W.F. (1953). A Cyto-taxonomic study in the genus Eupatorium. Amer. J. Bot. 40: 729 - 742. KING, R.M. & H. ROBINSON (1970). Eupatorium A composite genus of Arcto-tertiary distribution. Taxon 19: 769 - 774. RAO, R.R. & M.K.V. RAO (1980). the genus Eupatorium L. (Asteraceae) in North East India. Proc. Ind. Nat. Sci. ACad. B. 46: 587 - 592.
Distributed in Europe, Asia, Africa but chiefly in Mexico, West Indies and Tropical S. America; ca 1200 species, 10 in India.
Literature. BENNETT, F.D. & V.P. RAO (1968). Distribution of an Introduced weed Eupatorium odoratum L. (comp.) in Asia & Africa and Possibilities of its Biological Control. PANS 14(3): 227 - 281. GRANT, W.F. (1953). A Cyto-taxonomic study in the genus Eupatorium. Amer. J. Bot. 40: 729 - 742. KING, R.M. & H. ROBINSON (1970). Eupatorium A composite genus of Arcto-tertiary distribution. Taxon 19: 769 - 774. RAO, R.R. & M.K.V. RAO (1980). the genus Eupatorium L. (Asteraceae) in North East India. Proc. Ind. Nat. Sci. ACad. B. 46: 587 - 592.
KEY TO THE SPECIES
| 1a. Leaves finely dissected into capillary segments | 3. Eupatorium capillifolium |
| b. Leaves not as above | 2 |
| 2a. Leaves 3-5 fid; segments lanceolate | 2. Eupatorium cannabinum |
| b. Leaves simple | 3 |
| 3a. Achenes with shining glands | 4 |
| b. Achenes without glands | 5 |
| 4a. Leaves palmately 3-5 nerved; involucral bracts mostly acute | 7. Eupatorium nodiflorum |
| b. Leaves penni-nerved; involucral bracts all obtuse | 4. Eupatorium chinense |
| 5a. Leaves entire | 6 |
| b. Leaves serrate or toothed | 7 |
| 6a. Heads many flowered; involucral bracts 3-seriate | 10. Eupatorium triplinerve |
| b. Heads 4-8 flowered; involucral bracts sub 2-seriate | 6. Eupatorium ligustrinum |
| 7a. Leaves obovate, 7-nerved | 5. Eupatorium erythropappum |
| b. Leaves lanceolate, oblong-obovate, elliptic or rhombic-deltoid, 3 nerved from base or penninerved | 8 |
| 8a. Involucral bracts 1-2 seriate, equal in length | 9. Eupatorium riparium |
| b. Involucral bracts 1-many seriate, outer smaller than the inner | 9 |
| 9a. Heads 4-8 flowered; involucral bracts sub 2-seriate | 6. Eupatorium ligustrinum |
| b. Heads many flowered; involucral bracts 3-5 seriate | 10 |
| 10a. Stems, petioles and involucral bracts glandular hairy; achenes glabrous | 1. Eupatorium adenophorum |
| b. Stems sparsely pubescent; achenes hairy on the ribs | 8. Eupatorium odoratum |
