New combinations in Asiatic Oxybasis (Amaranthaceae s.l.): evidence from morphological, carpological and molecular data

Abstract

Two new combinations are proposed in Oxybasis (Chenopodioideae, Chenopodiaceae or Amaranthaceae s.l.). Chenopodium micranthum, described from Russia in the 1860s and known as C. urbicum subsp. sinicum in China, is assigned specific rank in Oxybasis. It appears to be widespread in China, Mongolia, Kazakhstan and Asiatic Russia. The Siberian-Mongolian C. gubanovii, recently described as a new species in Chenopodium sect. Pseudoblitum, is also assigned to Oxybasis. Molecular phylogenetic analysis using maximum likelihood (ML) and maximum parsimony (MP) methods confirmed the placement of C. micranthum and C. gubanovii in the genus Oxybasis. Distribution maps of O. micrantha and O. gubanovii are provided, the latter species being reported for the first time in the Chinese part of the Altai Mountains. A lectotype for C. micranthum (= O. micrantha) is designated.

Molecular phylogenetic data and seed coat anatomy resolve the generic position of some critical Chenopodioideae (Chenopodiaceae – Amaranthaceae) with reduced perianth segments

“… nuttallianum ), is reduced to 1–2 leaves that may wither away completely by anthesis. From this study and from previous work ( Sukhorukov and Zhang 2013 ; Sukhorukov et al 2013 ; Sukhorukov 2014 ), it is evident that another character, the structure of the testa cells of the seed coat, is also diagnostic. In Oxybasis , as well as almost all other Chenopodieae , the seed testa cells have a reduced protoplast and “stalactites” hanging vertically in the outer wall (stalactite seed coat).…”

“…Some of the most recent and drastic taxonomic changes have been proposed by Fuentes-Bazan et al (2012b) following their phylogenetic study of the large genus Chenopodium (~200–250 species) ( Fuentes-Bazan et al 2012a ) and this classification is currently accepted by many authors (e.g. Iamonico 2011 , 2014 ; Mosyakin 2013 ; Uotila 2017 ; Sukhorukov et al 2013 ; Sukhorukov and Kushunina 2014 , Hernández-Ledesma et al 2015 ; Mosyakin and Iamonico 2017 ). According to the findings by Fuentes-Bazan et al (2012b) , Chenopodium sensu lato was shown to be polyphyletic and members previously included in the genus are now placed in tribes Chenopodieae incl.…”

“… Pseudoblitum ( Sukhorukov 1999 ). Its generic status was discussed by Fuentes-Bazan et al (2012b) and finally resolved by Sukhorukov et al (2013) as being a part of Oxybasis [ Oxybasis gubanovii (Sukhor.) Sukhor.…”

Taxonomic revision of Chenopodiaceae in Himalaya and Tibet

“…The anatomy of the fruit and seed is important for the diagnostics and taxonomy of many Chenopodiaceae (for more see, e.g. Sukhorukov 2008, 2014, Sukhorukov and Zhang 2013, Sukhorukov et al 2013, 2014, 2015a). The fruit anatomy appears crucial to the diagnostics of many Corispermum and the fruits of almost all members were anatomically investigated in previous studies (Sukhorukov 2007a, 2007b, 2014, Sukhorukov et al 2014).…”

Taxonomical, Morphological, Ecological And Chorological Notes On Oxybasis Chenopodioides And O. Rubra (Chenopodiaceae) In Italy

“…The genus Oxybasis was resurrected to accomodate the Chenopodium species with branched stem, leaves not in basal rosette, inflorescence in not fleshy glomerules and usually dimorphic flowers with 3-5 tepals and horizontal and vertical seeds (Fuentes-Bazan et al 2012a, Sukhorukov 2013. Four European and Italian taxa Oxybasis chenopodioides and O. rubra represent a critical pair of species having fairly similar gross morphology, even though they do not seem to be close relatives (see e.g.…”