Acuston petalodes (DC.) Al-Shehbaz

AL-Shehbaz, Ihsan A. & Barriera, Gabrielle, 2019, Typification of Edmond Boissier’s Cruciferae (Brassicaceae) names enumerated in Flora Orientalis, Boissiera 72, pp. 1-193 : 86

Acuston petalodes (DC.) Al-Shehbaz , comb. nov.

 Alyssum petalodes DC., Syst. Nat. 2: 312. 1821.

Type: “Hab. in Syriâ. Labillardiere. (v.s. sp. in h. Labill.)”.

Holotypus: SYRIA: sine loco, 1819, Labillardi è re s.n. ( G [ G00371675 ]; iso-: G-DC [ G00205585 ]) .

Notes. – CANDOLLE (1821b: 312) indicated that he examined the material in Labillardière’s herbarium, but as shown by STAFLEU & COWAN (1979), collections of that herbarium from Syria, which were in Lemonnier’s herbarium, are currently housed in the Geneva herbaria.

A search for possible duplicates in the VIRTUAL HERBARIA (2019) and P (including P-JU and P-LA), where many of Labillardière duplicates are currently housed, did not yield anything. Therefore, the listing of the holotype in P by AL-SHEHBAZ & MABBERLEY (2017) is erroneous.

By contrast, the G00371675 specimen is from Labilladière’s herbarium with two different labels indicating Syria and Liban but no date, and it is concluded here that this is the holotype. The G-DC specimen above is a fragmentary material with a label in Candolle’s handwriting “Alyssum petaloideam. M.Labillard. 1819” but no country or locality. The conclusion is that it was taken by Candolle from the holotype and, therefore, it is an isotype.