Ageratum conyzoides L., 1753

Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part A), Order out of Chaos. Linnaean Plant Types and their Types, London: Linnaean Society of London in association with the Natural History Museum, pp. 252-342 : 269

Ageratum conyzoides Linnaeus , Species Plantarum 2: 839. 1753.

"Habitat in America." RCN: 6073.

Lectotype (Grierson in Dassanayake & Fosberg, Revised Handb. Fl. Ceylon 1: 141. 1980): Herb. Clifford: 396, Ageratum 1 (BM-000646956) .

Generitype of Ageratum Linnaeus (vide Green, Prop. Brit. Bot.: 180. 1929).

Current name: Ageratum conyzoides L. ( Asteraceae ).

Note: The earliest effective typification appears to be by Grierson (in Dassanayake & Fosberg, Revised Handb. Fl. Ceylon 1: 141. 1980), who indicated Clifford material (BM) as type. As discussed by Barrie & al. (in Taxon 41: 510. 1992), this material is identifiable as Eclipta prostrata (L.) L. There are no grounds for rejecting the typification. Reveal (in Jarvis & al., Regnum Veg. 127: 15. 1993) indicated a Hermann illustration (Parad. Bat.: ic. 161. 1698), which does agree with current usage of the name, as lectotype. However, this later typification does not have priority. It appears that, to avoid disruption to the generic names Eclipta and Ageratum , a conservation proposal will be necessary (although the application of these names may be temporarily protected by Art. 57.1).