Isatis candolleana Boiss.

AL-Shehbaz, Ihsan A. & Barriera, Gabrielle, 2019, Typification of Edmond Boissier’s Cruciferae (Brassicaceae) names enumerated in Flora Orientalis, Boissiera 72, pp. 1-193 : 157

Isatis candolleana Boiss. in Ann. Sci. Nat., Bot. ser. 2, 17: 199. 1842.

Type: “[Aucher-Eloy] N. 215, Taurus”.

Lectotypus (designated here): TURKEY: “Taurus”, 1837, Aucher-Eloy 215 ( G [ G00371798 plant on left with glabrous fruit]; isolecto-: G-BOIS [ G00332591 fragment on left with glabrous fruit], P [ P00741461 ]) ( Fig. 32 , p. 124) .

Notes. – The specimen in G-BOIS is a mixed collection of fragments both of which were almost certainly taken from the more complete lectotype specimen that was studied by Boissier and consists of two complete plants also representing two taxa. Therefore, the name needs lectotypification.

BOISSIER (1842b) noticed that one plant had glabrous fruit and the other has densely velutinous ones, and he recognized them as var. α and β, respectively. He questioned if the glabrous plant (var. α) might be the same as I. leiocarpa DC. , but this is a different taxon that belongs to I. cappadocica subsp. subradiata (Rupr.) P.H. Davis.

DAVIS (1965b: 297) described the fruit of I. candolleana as either velutinous or glabrous, thus agreeing with Boissier’s original concept of the species and overlooking the fact that two species are involved.

BOISSIER (1856) described I. velutina and cited a single collection (Huet du Pavillon s.n., see below), but he (Fl. Orient. 1: 377) added to the confusion by reducing I. candolleana to synonymy of the Caucasian I. latisiliqua Steven and cited its type collection, Aucher-Eloy 215 (Fl. Orient. 1: 378), as one of the three collections of I. velutina .

As lectotypified above, the plant with glabrous, smaller, purple fruit (var. α) is I. candolleana , whereas the plant with densely velutinous, larger, and yellowish fruit (var. β) should be attributed to I. velutina .

DAVIS (1965b: 296) overlooked the mixed type collections above and reduced I. velutina to synonymy of the earlier published I. candolleana , thus accepting a much broader species circumscription with drastically different fruit morphology.

There are other duplicates of Aucher-Eloy 215 (e.g., P00741508) that consist of only I. velutina .

Figures

Fig.32. Mixed collection including on the left the lectotype of Isatis candolleana Boiss. (p.157) and on the right a collection of I. velutina Boiss. & Huet (p.158) in G. [Aucher-Eloy 215]