Pentanema

Anderberg, Arne A. & Bengtson, Annika, 2022, Taxonomic novelties in the Asteraceae-Inuleae with the description of a new genus, Galgera separate from Laggera, Willdenowia 52 (3), pp. 373-386 : 378

Pentanema / Vicoa

Ling (1965) synonymized Vicoa with Pentanema ( Inuleae – Inulinae ), and until recently the genus was considered to be comprised of predominantly low, woody dwarf shrubs with small capitula and few capillary pappus bristles, although the two species P. divaricatum Cass. and P. vestitum (Wall. ex DC.) Y. Ling differ by being herbaceous. The distinction between Pentanema and Vicoa has been unclear, and the opinion has varied regarding what name to use for plants with inuloid habit and few pappus bristles. Russian authors, viz. B. A. Fedtschenko and O. A. Fedtschenko (Consp. Fl. Turkestanicae 4: 174. 1911), S. G. Gorschkova (Fl. URSS 25: 479. 1959), R. V. Kamelin (Fl. Sist. Vyssh. Rast. 1: 177. 1933), G. K. Kinzikaëva (Fl. Tadzhikskoi SSR 9: 528, 312. 1988), I. M. Krascheninnikov (Fl. Sist. Vyssh. Rast.1: 177. 1933), M. M. Nabiev (Opred. Rast. Sred. Azii 10: 462. 1993) and S. A. Nevski (Fl. Sist. Vyssh. Rast. 4: 280. 1937) have described several species from C Asia either as Vicoa or as Pentanema , and in some cases transferred species from one genus to the other. The analyses by Pornpongrungrueng & al. (2007), Englund & al. (2009) and Nylinder & Anderberg (2015) showed that P. indicum (former genus Vicoa ) and P. ligneum Mesfin belong to a lineage more closely related to Blumea and Duhaldea DC. than to the type of Pentanema ( P. divaricatum ), hence meriting recognition of Vicoa as a genus separate from Pentanema . Englund & al. (2009) also showed that Inula L. was paraphyletic, with most species belonging to another clade than I. helenium L. (the type of Inula ). This led Gutiérrez-Larruscain & al. (2018) to transfer a large number species from Inula to Pentanema , and they also reinstated the genus Vicoa . Most C Asian species named Vicoa belong to the group today known as Pentanema and not to the same clade as the type of Vicoa ( V. auriculata Cass. = V. indica [≡ P. indicum ]).

Vicoa now counts the following species: (1) V. indica (L.) DC. (≡ Inula indica L. ≡ Pentanema indicum (L.) Y. Ling = [among others] Inulaster kotschyi Sch. Bip. , V. auriculata Cass. and V. leptoclada (Webb) Dandy ≡ Inula leptoclada Webb ); (2) V. cernua Dalzell (≡ P. cernuum (Dalzell) Y. Ling = V. gokhalei Gosavi & al.); (3) V. lignea (Mesfin) D. Gut. Larr. & al. (≡ P. ligneum Mesfin ); (4) V. sahyadrica Nandikar & Sardesai.

Our analyses support the separation of Vicoa from Pentanema ( Fig. 1), and we have also found a yet undescribed species from China belonging to the Vicoa clade ( V. anisopappoides Anderb. & Bengtson , described below). In our study, V. anisopappoides and V. indica group together ( Fig. 1). The morphologically similar species V. cernua is most likely a close relative of V. indica , as is the recently described V. sahyadrica from India ( Nandikar & Sardesai 2021). Vicoa is placed here in an unresolved clade together with the Blumea clade, the monotypic genus Caesulia Roxb. , and the Somalian V. lignea ( Fig. 1). In Pornpongrungrueng & al. (2007), analyses of ITS and plastid data placed P. cernuum , P. indicum and P. ligneum together in a clade sister to Caesulia and the Blumea clade. Vicoa indica has a distribution in tropical and subtropical regions from W Africa to China. Vicoa cernua is found in similar conditions from Pakistan to SE Asia, V. sahyadrica is endemic to India and V. lignea is endemic to Somalia. The new species V. anisopappoides is known only from Yunnan in China.