Amaranthus melancholicus var. obovatus Moquin-Tandon (1849: 262)

Iamonico, Duilio, 2016, Nomenclature survey of the genus Amaranthus (Amaranthaceae). 5. Moquin-Tandon’s names, Phytotaxa 273 (2), pp. 81-114 : 100-101

26. Amaranthus melancholicus var. obovatus Moquin-Tandon (1849: 262)

Type (lectotype here designated):— GERMANY. Sprenger, in ruderatis, 08 August 1889, Callier s.n. (P05234153 [digital image!], image of the lectotype is available at http://mediaphoto.mnhn.fr/media/14413951927097z8Rx6ctKpn5hPhp).

= Amaranthus tricolor Linnaeus (1753: 989) . Type (lectotype designated by Townsend 1974: 14):—ASIA. Habitat in India, Herb. Linn. No. 1117.7 (LINN [digital image!], image of the lectotype is available at http://linnean-online.org/11633/).

Nomenclatural notes:—A very shor diagnosis was provided for the var. obovatus : “foliis minoribus obovatis”. No synonyms, specimens or provenance were cited in the protologue. I have not been able to trace specimens of original material and no lectotypification can be made. As a consequence, a neotype should be designated (Art. 9.7 of the ICN).

Moquin-Tandon (1849: 262) recognized three varieties under Am. melancholicus (= Am. tricolor ) based on the shape and size of the leaves: var. tricolor has leaves blades lanceolate to lanceolate-ovate, var. obovatus has leaves obovate smaller than the var. tricolor (”foliis minoribus” in the protologue), while var. parvifolius has leaves rhombic much smaller than the var. tricolor (”foliis multo minoribus”). On the basis of the lectotype designated for the var. parvifolius (see below, the name no. 26), the description of Am. melancholicus the illustration cited by Moquin-Tandon (l.c.) for var. tricolor (”Lam. ill. t. 767, f. 1”, available at http://www.biodiversitylibrary.org/item/104400#page/41/ mode/1up; Lamarck 1796), and other specimens, it is possible to understand the Moquin-Tandon’s concept of the var. obovatus . I found a specimen at P (barcode 05234153) bearing two parts of a same plant with leaves blades obovate (2.0−3.0 cm long) and intermediate in size between var. parvifolius (0.5−2.0 cm long) and the var. tricolor (7.0−18.0 cm long). I here designated the P05234153 as the neotype of the name Am. melancholicus var. obovatus .

Taxonomical notes:—According to the current concept, Am. melancholicus is to be referred to Am. tricolor , a species showing a high morphohlogical variability of both vegetative and sexual characters (see e.g., Akeroyd 1993, Bojian & al. 2003, Mosyakin & Robertson 2003). The leaves shape has no taxonomic value in Am. tricolor and I here propose to synonymize the var. obovatus with the Linnaean Am. tricolor .