Oreosalsola Akhani, 2016

Akhani, Hossein, Khoshravesh, Roxana & Malekmohammadi, Maryam, 2016, Taxonomic novelties from Irano-Turanian region and NE Iran: Oreosalsola, a new segregate from Salsola s. l., two new species in Anabasis and Salvia, and two new combinations in Caroxylon and Seseli, Phytotaxa 249 (1), pp. 159-180 : 162-163

Oreosalsola Akhani , gen. nov. ( Fig. 1A, C, D )

Type:― Oreosalsola montana (Litv.) Akhani ≡ Salsola montana Litv.

Diagnosis:―Shrubby species, with long annual shoots and spiciform to paniculate inflorescences, glabrous leaves and branches, with leaves constricted at the base, and deeply bifid styles. It differs from Salsola s.str. by the presence of only one flower per leaf axil and the absence of the Kranz layer in a leaf cross section, and performing as a nonC 4 photosynthetic type. The genus is most closely related to Salsola arbusculiformis Drobov (1916: 142) , a probable congener of Oreosalsola , but differs by minor characters such as glabrous leaves and branches (vs. papillose), glaucous leaves and branches (vs. deep green), and deeply bifid stigmas (vs. erect and shallowly bifid).

Species included:

Oreosalsola abrotanoides (Bunge) Akhani , comb. nov. Salsola abrotanoides Bunge (1879: 366) .

Oreosalsola botschantzevii (Kurbanov) Akhani , comb. nov. Salsola botschantzevii Kurbanov in Botschantzev et al. (1983: 237). Oreosalsola drobovii (Botsch.) Akhani , comb. nov. Salsola drobovii Botschantzev in Botschantzev & Vvedensky (1941: 3). Oreosalsola flexuosa (Botsch.) Akhani , comb. nov. Salsola flexuosa Botschantzev (1975: 1158) .

Oreosalsola lipschitzii (Botsch.) Akhani , comb. nov. Salsola lipschitzii Botschantzev (1975: 1159) .

Oreosalsola montana (Litvinov) Akhani , comb. nov. Salsola montana Litvinov (1917: 3) .

Oreosalsola masenderanica (Botsch.) Akhani , comb. nov. Salsola masenderanica Botschantzev (1974: 832) .

Oreosalsola oreophila (Botsch.) Akhani , comb. nov. Salsola oreophila Botschantzev (1975: 1159) .

Oreosalsola tianschanica (Botsch.) Akhani , comb. nov. Salsola tianschanica Botschantzev (1975: 1160) .

The N African species Salsola gymnomaschala Maire (1938: 446) may also belong to Oreosalsola , but as we have not seen this plant, we prefer to wait until a phylogenetic and comparative morphology support its position.

The monophyly of species belonging to the Salsola montana aggregate has been confirmed in phylogenetic trees based on nuclear ITS and chloroplast psb B- psb H sequences (Akhani et al. 2007, Wen et al. 2010, Voznesenskaya et al. 2013) ( Fig. 1 ). Oreosalsola is characterized by the sympegmoid leaf anatomy in which a multilayer (2–3)

chlorenchymatous tissue surrounds peripheral vascular bundles and the water storage tissue. Additionally, there is often an indistinct layer of relatively small bundle sheath cells around the peripheral vascular bundles in two studied species, O. montana and O. masenderanica ( Fig. 1G , see also Voznesenskaya et al. 2013, Figs. 2A, B, E, F ; Akhani &

Ghasemkhani 2007).

Morphologically and phylogenetically, Oreosalsola is very similar to Salsola arbusculiformis (“ Collinosalsola ”).

The main differences are the relatively long inflorescences and glaucous annual branches, deep bifid divergent stigmas in Oreosalsola , in contrast to dark green annual branches, shorter inflorescences and less divided stigmas in

“ Collinosalsola ” ( Fig. 1E, F ). Morpho-physiological studies have revealed that S. arbusculiformis is an intermediate

C 3 -C 4 with a more developed layer of bundle sheath cells around peripheral vascular bundles ( Voznesenskaya et al. 2001). The next relative of this species, Salsola laricifolia Turcz. ex Drobov (1927: 210) , also performs C 3 -C 4 intermediacy ( Wen & Zhang 2015). Both two species were informally classified under “ Collinosalsola ” (Akhani et al. 2007). However, our further studies and updated phylogenetic analysis ( Fig. 2 ) suggest that two other species of

Salsola , S. arbusculiformis and S. laricifolia are closely related to and more likely congeneric with Oreosalsola .

In contrast to C 4 species of Salsoleae Dumortier (1827: 366) that grow in lowlands under high temperature and salinity, Oreosalsola species are ecologically adapted to higher elevations and colder climates. Along an elevational gradient in Golestan National Park in NE Iran, the C 4 chenopods are dominant in the lowermost plain.Then, the vegetation is replaced with a mix of Artemisia and Salsola arbusculiformis towards sloping grounds and foothills. Finally, higher up marl hills are covered with a mixture of Artemisia and Oreosalsola montana ( Akhani & Ghasemkhani 2007) . This is still an unanswered question whether C 3 and C 3 -C 4 taxa of Salsoleae such as Oreosalsola , “ Collinosalsola ” (including Salsola arbusculiformis and S. laricifolia ) and “ Canarosalsola ” (incl. Salsola divaricata Masson ex Link (1825: 141))

keep the plesiomorphic C 3 features in suitable ecological habitats or they have evolved from C 4 ancestors.

In our phylogenetic tree we have included the recently described species Salsola austro-iranica Akhani (2015: 286) and the new transfer S. kavirensis Akhani (2015: 491) together with S. soda Linnaeus (1753: 223) , the type species of the genus, and four selected species of Kali . The results support a strong monophylly of Salsola s.str. as interpreted by Akhani et al. (2007, 2014). Further, it reconfirms the monophylly of Kali which appears to be sister to other species studied and analyzed in this paper ( Fig. 2 ). The recent claim by Mosyakin et al. (2014) considering that Salsola s. str. should include only S. soda and S. acutifolia (Bunge 1847: 477) Botschantzev (1963b: 29) is unfounded. The genus includes at least 27 species widely diversified and distributed in Africa and Asian deserts. On the other hand, Kali with c. 20 species ( Hernández-Ledesma et al. 2015) includes mostly ruderal species for which all necessary combinations are available and widely accepted by the botanists working with this group (e.g. Brullo et al. 2015a, 2015b). In conclusion, accepting the proposal suggested by Mosyakin et al. (2014) to conserve the genus Salsola with a new type may increase instability and chaos in the taxonomy of this group and encourage new and unnecessary nomenclatural changes. Salsola kali is not a crop plant with high economic importance that changing its name could cause a big problem for the scientific and public community. Replacing this name with Kali turgidum ( Dumortier 1827: 23) Gutermann (2011: 98) is similar to many changes which recent molecular studies that necessitated changing plant names according to the rules of botanical nomenclature. The generic name “ Kali ” has an advantage that those unfamiliar with taxonomy could get similar results even if they search for Salsola kali using internet search engines.

Figures

FIGURE 1. Oreosalsola montana. A. Fruiting branch. C. Ovary. D. Stamen. G. Cross section of leaf showing multiple mesophyll layers. H. Young stem represent non-Kranz photosynthetic tissue. Salsola “Collinosalsola” arbusculiformis. B. Fruiting branch. E. Stamen. F. Ovary. Scale bars: 500 μm for C, F. 700 μm for D, E. 60 μm for G and H.

FIGURE 2. The 50% majority rule tree from Bayesian Inference analysis of ITS sequences of 36 taxa/accessions of Salsoleae and Sympegma regelii as outgroup, showing the relationship of Oreosalsola, Kali, Salsola s.str., and the position of Anabasis firouzii and A. setifera. The numbers above branches show posterior probabilities. *The accession number EF453389 was wrongly reported in Akhani et al. (2007) under Anabasis setifera.