Amaranthus paniculatus var. monstruosus Moquin-Tandon (1849: 257)

Iamonico, Duilio, 2016, Nomenclature survey of the genus Amaranthus (Amaranthaceae). 5. Moquin-Tandon’s names, Phytotaxa 273 (2), pp. 81-114 : 102

29. Amaranthus paniculatus var. monstruosus Moquin-Tandon (1849: 257)

Type: not designated.

Nomenclatural notes and taxonomic remarks:— Moquin-Tandon (1849: 257) named this variety as “ monstruosus ” referring to the synflorescence structure, which is “...longissima crassa (rhachi fasciata) densiflora, lateralibus nullis...”). No synonyms, specimens or provenance were cited in the protologue. No original material was traced, and a neotypification is required (Art. 9.7 of the ICN).

Among the six varieties recognized by Moquin-Tandon (1849: 257) under Am. paniculatus (= Am. cruentus ), the author intended to distinguish forms with a very particular structure of the synflorescences. In my opinion, on the basis of the phrase “rachi fasciata ”, the protologue refers to teratogenous plants. The malformations of the plants were well documented in the last four centuries by the publications of many iconographies (see Spallino et al. 2014 and literature therein) and some important contributions were published in XIX and XX century (e.g., Master 1869, Wordsdell 1915, 1916). These anatomical anomalies are caused by chemicals and phytoathogens ( Agrios 2005), which affect all the parts of plants, both vegetative (stems, leaves) and sexual (flowers). Also Moquin-Tandon (1841) in his Éléments de Tératologie Végétale highlighted the plant malformations, although any amarant was cited. Personal field surveys allowed me to verify that this phenomenon is not so rare in Amaranthus especially in stem banding alteration.

From the taxonomical point of view, it is clear that malformations in plants have not value. The typification of the name Am. paniculatus var. monstruosus is unless as well as a proposal of synonymization whit any other Amaranthus name.