Senecio sternbergianus DC., Prodr., DC. & Prodr.

Calvo, Joel & Granda, Arturo, 2022, On the taxonomic identity of five Senecio species (Compositae) described by Candolle on material collected by Haenke during the Malaspina Expedition, Candollea 77 (2), pp. 145-158 : 154-156

4. Senecio sternbergianus DC., Prodr. 6: 425. 1838, syn. nov.

Lectotypus (designated here): CHILE: sine loco, s.d., Haenke s.n. (PR-495639 image!; isolecto-: PRC [ PRC453192 ] image!) (F ig. 6) .

= Senecio fistulosus Poepp. ex Less. in Linnaea 6(2): 246. 1831. Lectotypus (designated by F REIRE et al., 2014: 112): CHILE. Reg. Valparaíso: in paludos. ad “ Lagunas de Quintero ”, s.d. [1827–1829], Poeppig 230 [pl. Chil. I.] (P [ P01816804 ] image!; isolecto-: HAL [ HAL0111053 ] image!, NY [ NY00259169 ] image!, P [ P01816803 ] image!).

Notes. – The locotype indication of Senecio sternbergianus reads: “in montibus Peruanis legit cl. Haenke”. There is original material of this species at PR and PRC, both identified by Candolle’s hand, who also annotated “P.m.” on the label of the specimen PRC 453192, most likely referring to Peruvian mountains. These specimens are not in the best condition, however, they show herbaceous plants with basal leaves quite large and lengthy petiolate, cauline leaves abruptly decreasing in size up the stem and becoming semiamplexicaul, and synflorescences terminal, corymbiform, composed of radiate capitula. There is little doubt that the species belongs to Senecio sect. Hualtatini (DC.) Cabrera , which comprises c. 15 species distributed in Argentina, Chile, Bolivia, Paraguay, Uruguay, and SE Brazil ( CABRERA , 1950; F REIRE et al., 2014). No species of this group are known from the Peruvian territory, which appears to have the northern limit of distribution in Bolivia.

DILLON & HENSOLD (1993) treated Senecio sternbergianus as a synonym of Aequatorium stellatopilosum (Greenm. & Cuatrec.) C. Jeffrey, but this is a tree with long-petiolate leaves and no basal leaves. Later, VISION & DILLON (1996) did not mention it in their checklist of the Peruvian Senecio . In our opinion, this is clearly another case of species described upon mislabeled Haenke’s specimens. Although the original material is not well-preserved, the specimens are very similar to Senecio fistulosus Poepp. ex Less. This species is distributed in centralsouthern Chile and the bordering areas in Argentina, thriving in wet and boggy places. Because it grows in marshes and swamps nearby the main historical Chilean ports (i.e. Concepción, Valparaíso, Coquimbo), S. fistulosus has been collected by most naturalists that participated in the early botanical expeditions to the New World, e.g., H. Ruiz-J. Pavón-J. Dombey in 1782 (CALVO, 2022b), A. von Chamisso in 1816, C.G. Bertero in 1828, etc. Indeed, we found a Née collection kept at MA corresponding to this species that bears a label with the information: “780 Valparaiso & Coquimbo ”. MUÑOZ GARMENDIA (1994) reported that Haenke joined the Expedition in Santiago de Chile in 2 April 1790 (from Buenos Aires) and they remained in Valparaíso until 14 April, when sailed to Coquimbo. Therefore, the possibility that Haenke collected the original material of S. sternbergianus nearby Valparaíso or Coquimbo exists.

On the basis of the morphology of the type material and because we are aware of the vicissitudes behind the Haenke material, we here synonymize the name Senecio sternbergianus with S. fistulosus .