Eupatorieae Cass.
Annual or perennial herbs or shrubs, rarely trees or epiphytes, strongly scented or not, lacking latex. Lvs usually opposite, rarely alternate or verticillate. Involucral bracts in 2-many rows, herbaceous or chartaceous. Receptacle with or without scales. Capitula ⚥, with all florets ⚥ and usually tubular, the outer florets sometimes slightly zygomorphic. Anthers obtuse or rarely sagittate at base. Style branches each with 2 stigmatic lines. Achenes homomorphic, usually terete and 5-ribbed, rarely 10-ribbed, rarely flattened and 2-ribbed; pappus usually of scabrid to plumose hairs, rarely of scales or 0.
Key
160 genera, c. 2000 spp., cosmopolitan but mainly America.
Most treatments of Eupatorieae accept a very broad concept of Eupatorium, but King, R. M., and Robinson, H., Taxon 19 : 769-774 (1970), have redefined the genus and admit only about 37 spp. These authors have substantially revised generic concepts for most of the tribe and their work is followed here (see, Robinson and King, in Heywood et al. (op. cit.).
