Euxolus sect. Berlasia Moquin-Tandon (1849: 272)

Iamonico, Duilio, 2016, Nomenclature survey of the genus Amaranthus (Amaranthaceae). 5. Moquin-Tandon’s names, Phytotaxa 273 (2), pp. 81-114 : 105-106

36. Euxolus sect. Berlasia Moquin-Tandon (1849: 272)

Type (lectotype here designated):— Euxolus polygamus ( Linnaeus 1755: 32) Moquin-Tandon (1849: 277) .

Nomenclatural notes:— Moquin-Tandon (1849: 272−273) recognized two sections under Euxolus , sect. Berlasia (new section), and sect. Penturius (Raf.) Moq. (new combination), which differ each other on the basis of the synflorescence structure: axillary glomerules in the sect. Berlasia, terminal spike-like synflorescence in the sect. Penturius. The sect. Berlasia includes two species, E. polygamus , and E. undulatus (R.Br.) Moq. Since the latter species was marked with a question mark (“ E.? undulatus ), a “ Signum dubitationis ” according to the “SIGNORUM PRODROMI EXPLICATIO” (see after the title page of the Prodromus ), I suppose that Moquin-Tandon had doubt about including the Brown’s species under the genus Euxolus , so I prefer to designate E. polygamus as the lectotype of the name Euxolus sect. Berlasia .

Taxonomical notes:—A short diagnosis (“ Flores in glomerulis axillares parvolus subdistante congesti. Utriculi apice 2–3-dentati ”) was provided to describe the new section. The two species listed, E. polygamus , and E. undulatus , include plants with 3 sepals and dehiscent fruit ( E. polygamus ), or with 5 tepals and circumscissile dehiscent fruit ( E. undulatus , see also Palmer 2009). On the basis of the scheme proposed by Mosyakin & Robertson (1996: 279−280), the sect. Berlasia certainly belongs to the subgen. Albersia that includes all the taxa belonging to the sect. Blitopsis Dumort. sensu lato (see also Carretero 1985). However, at sectional level [4 groups were accepted, sect. Blitopsis, sect. Pentamorion (G.Beck) Mosyakin & K.R.Robertson), sect. Goerziella (Urban) Mosyakin & K.R.Robertson , sect. Pyxdium], it is not possible to place the sect. Berlasia. Actually, Mosyakin & Robertson (1996) have not cited this section, while they synonymized the Moquin-Tandon’s sect. Penturius with the sect. Blitopsis. Sect. Blitopsis includes species with indehiscent utricles and mostly trimerous flowers, a characterization that does not match with the features of both the Moquin-Tandon’s taxa listed in the Prodromus . Specifically, E. polygamus (≡ Am. polygamus L. ≡ Am. tricolor L., see Iamonico 2014a: 147−148) can be placed into Am. subgen. Albersia sect. Pyxidium , while E. undulatus cannot be included in any of the sections recognized by Mosyakin & Robertson (1996) since the combination of the characters (5 tepals and dehiscent fruit) were not considered by these authors. Despite that, Mosyakin & Robertson (1996) cited E. undulatus (sub Am. pallidiflorus F.Muell. , now considered a later heterotypic synonym according to Palmer 2009) under the sect. Pentamorion, which should include species with 5 tepals and indehiscent fruit. The same authors ( Mosyakin & Robertson 1996) stated: “ A. pallidiflorus …and A. clementii …are probably also related to this section [sect. Pentamorion]”. A possible taxonomic solution could be the creation of a new section or a subsection of the sect. Pentamorion. On the whole, Mosyakin & Robertson (1996) highligthed that the scheme proposed for subgen. Albersia still remains unsatisfactory, and “ The best taxonomic solution…seems to be the recognition of several narrower section and subsections… ” (see Mosyakin & Robertson 1996: 279). Concerning the sect. Pentamorion, they argued that the Australian taxa listed ( Am. interruptus R.Br. , Am. clementii Domin , Am. mitchellii Benth. , and Am. pallidiflorus F.Muell. ) “ deserve recognition at least at subsectional level ” (see Mosyakin & Robertson 1996: 280). The ongonig nomenclatural study on the Australian names (Iamonico & Palmer in prep.) seems to confirm the recognition of a new section for the Australian species, but I here prefer to avoid final conclusions, waiting the end of the investigation of all the taxa occurring in Australia.

All things stated the sect. Berlasia can be considered a pro parte synonym of both Am. subgen. Albersia sect. Pentamorion , and Am. subgen. Albersia sect. Pyxidium .

37. Euxolus deflexus var. major Moquin-Tandon (1849: 275)

Type (neotype here designated):—UNKNOWN ORIGIN. s.d., Willdenow (Herb. Poiret) s.n. (P 04021943 [digital image!], image of the neotype is available at http://mediaphoto.mnhn.fr/media/1449489970138PbY0nrw7ydQ8bVMR).

= Amaranthus deflexus Linnaeus (1771: 295) .

Type (lectotype designated by Aellen 1972: 7):—UNKNOWN ORIGIN. Herb. Linn. No. 1117.18 (LINN [digital image!], image of the lectotype is available at http://linnean-online.org/11644/).

Nomenclatural notes:— Moquin-Tandon (1849: 275) provided a short diagnosis (“robustior, caule ascendente vel erecto, foliis majoribus”), while no exsiccata were cited. Two specimens were traced at P (barcodes 04021943, and 04021944), which bear pieces of plants collected by C. L. Willdenow and included in the Poiret’s collection as reported in the original label [“ amaranthus ... herb. Poiret ” (P 04021943 image available at http://mediaphoto.mnhn.fr/media/ 1449489965164hAhYUIDSKILFk9Nh), and “ amaranthus prostratus | herb. Poiret ” (P 04021944)]. Since the date of collection is lacking in both the specimens, I prefer to avoid them for the lectotypification and designated the P 04021944 as the neotype of the name Euxolus deflexus var. major according to the Arts. 9.2, 9.3, and 9.7 (no other specimens were traced).

Taxonomical notes:— Moquin-Tandon (1849: 275) recognized three infraspecific taxa under Euxolus deflexus [≡ Am. deflexus Linnaeus (1771: 295) ]—var. (β) ascendens, var. (γ) major , and var. (δ) minor ― the latter two varieties as new for science. The var. major would differ by its stem (“ caule ascendente vel erecto ”) and leaves size (“ foliis majoribus ”). However, these characters have a low taxonomic value in Amaranthus (except few cases) and Am. deflexus shows a high morphological variability concerning the size of the leaves. The plant beared in the specimen P 04021944 (neotype) completely matches with Am. deflexus from the morphological point of view (see e.g., Akeroyd 1993, Mosyakin & Robertson 2003, Iamonico 2015). As a consequence I here propose to treat the var. major as heterotypic synonym of Am. deflexus .