Typification of Arctium lappa L. (Asteraceae)

Abstract

Arctium lappa L. in its present interpretation is a widespread, very distinct species; for diagnostic characters see Duistermaat (1996: 78). So far, no lectotype of A. lappa has been designated (see Linnaean type register on the Natural History Museum's Web site: http:// www.nhm.ac.uk/botany/linnaean/). Moreover, the specimen named A. lappa in the Linnaean herbarium (964.1, LINN!) and which appears to have been in Linnaeus' possession prior to 1753 (Savage, 1945: 141), belongs to what is now known as A. tomentosum Mill. Later authors never appear to have had any difficulty in distinguishing this species from A. lappa (Duistermaat, 1996). Other original material, associated via Linnaeus' (1753: 816) citation of Hortus Cliffortianus (Linnaeus, 1738: 391), includes two specimens in the Clifford herbarium at BM (391, Arctium 1; and 391, Arctium 1 3; BM!), images of which can be viewed at http:// www.nhm.ac.uk/botany/databases/clifford/). Both specimens are of A. tomentosum. Linnaeus (1753: 816) also cites: Roy. Lugb. 141., i.e., Flora Leydensis (van Royen, 1740: 144) and two synonyms from Bauhin's Pinax (Bauhin, 1623: 198), the second being the basis of the P variety recognized by Linnaeus. No material of Arctium exists today in the van Royen herbarium (at L). Van Royen's reference to Morison (1699: 3, s7, c33) does lead to two specimens in the Morison herbarium (OXF, photographs sent to me through Prof. D. Mabberley) that are referable to A. minus Bemh. (146, 1), and A. tomentosum (147, 2), but, not being seen by Linnaeus, these do not constitute original material. The Bauhin synonyms correspond to two specimens in the Burser herbarium (UPS, L microfiche!; see also Savage, 1937), which Linnaues used, and represent Arctium minus (X, 159), and A. tomentosum (X, 160), the latter representing the synonym cited by Linnaeus under his 3 variety. Linnaeus (1753) also cited two works containing illustrations of the species as he understood it. The earliest is an illustration of Bardana, siue Lappa major by Dodonaeus (1583: 38)-the page mistakenly cited by Linnaeus as 58. It is a very sketchy woodcut, which could fit either A. lappa or A. tomentosum. The identity is therefore equivocal. The illustration by Camerarius (1586: 887) (photocopy sent to me by Dr. C. Jarvis, BM) is more like A. minus. To summarize, there is no herbarium material seen by Linnaeus that concurs with the presently generally accepted interpretation of A. lappa, and the illustrations in the works cited are equivocal at best. Assuming that one would not wish to apply the name A. lapppa to the species currently known as A. tomentosum (which would be contrary to Art. 57.1 of the ICBN, Greuter et al., 2000), there are, therefore, three options: (1) propose A. lappa for rejection under Art. 56, (2) propose the name for conservation with a new type (Art. 14.9), or (3) apply Art. 9.7. In order to avoid unnecessary nomenclatural changes, I reject the first option. Since illustrations of what could be A. lappa are available, we do not need to conserve the name, but can choose the third option instead. Consequently, I designate below the illustration by Dodonaeus (1583: 38) as the lectotype of A. lappa, and at the same time designate an epitype concurrent with the present delimitation of the species. It suits the locality mentioned in Linnaeus' (1753: 816) diagnosis: Habitat in Europae cultis ruderatis. This specimen is readily accessible for consultation through the illustration in Duistermaat (1996).