Salsola imbricata

Falatoury, Atiye Nejad, Iamonico, Duilio & Freitag, Helmut, 2017, Nomenclature of Caroxylon imbricatum s. lat. (Amaranthaceae / Chenopodiaceae), with a new combination at variety rank, Phytotaxa 331 (1), pp. 101-108 : 102

Salsola imbricata

Salsola imbricata was described by Forsskål (1775) from Lohajae [Al Luhayyah] in Yemen, but as the description was somewhat vague and no original material could be detected in Forsskål’s Arabian collections (see e.g., Hepper & Friis 1994: 107) for a long time, the name of the species was not generally accepted and the respective plants, except for those from Arabia, were mostly named either S. foetida or S. baryosma , both described from Egypt (see below). Botschantzev (1975: 166) typified S. imbricata by the illustration Tab. VIIIc in Forsskål’s (in fact, Niebuhr´s) Icones rerum naturalium (1776). Beside of S. imbricata , for a larger part of Arabia he also recognized S. baryosma that was said to differ by its curved hairs of the indumentum, slightly smaller tepals and style, as well as by less deeply split anthers. Botschantzev’s viewpoint was overtaken by Chaudhary & Akram (1986). Freitag (1989: 159) indicated that the respective illustration named S. imbricata and choosen by Botschantzev as the “ iconotypus ” in fact shows S. longifolia Forssk., and Hepper & Friis (1994) gave evidence that Forsskål had never seen the illustration. Freitag (l.c.) suggested to reject the name and to replace it by S. baryosma which, according to his experience, cannot be reliably separated as a species distinct from S. imbricata . All later authors agreed on a wider circumscription of the species, but Boulos (1991: 138) returned to the name S. imbricata by designating a neotype in K collected at Hodeida at the Red Sea coast of Yemen, about 100 km NNW of Forsskål’s locality.

Moquin-Tandon, while at first maintaining the name S. imbricata (1840: 142), recombined it later (1849: 177) as Caroxylon imbricatum , but subsequent authors from Fenzl (1851) to Iljin (1936) and Ulbrich (1936) reduced the genus Caroxylon Thunberg (1782: 37) to a section of Salsola until Tzvelev (1993) revived it based on morphological evidence. The genus rank of Caroxylon was definitely confirmed by molecular phylogenetic data of Akhani et al. (2007). Unfortunately, both authorships of C. imbricatum given in their publication are erroneous. “ Caroxylon imbricatum Moq. ” cannot be retained as a new species because it is evident that Moquin-Tandon (1849: 177) just proposed a nomenclatural combination based on Forsskål’s name Salsola imbricata , which Moquin-Tandon mentioned in synonymy. Consequently, “ Caroxylon imbricatum Moq. ” as cited in Akhani et al. (2007) is just an incorrect (incomplete) citation of the authorship of the name, and their new combination (cited with the authorship “(Forssk.) Akhani et Roalson”) should be regarded as a later isonym (Art. 6.3 Note 2 of the ICN).