Anemonastrum tenuicaule and A. antucense (Ranunculaceae), new combinations for a New Zealand endemic species and its South American relative

Abstract

A rational taxonomic circumscription of genera in tribe Anemoneae (Ranunculaceae) is briefly discussed. It is concluded that, in view of the morphological diversity of the group and recent molecular phylogenetic findings, a moderately narrow approach to the re-circumscription of genera earlier included in Anemone sensu lato is preferable, in particular, with the recognition of the lineage with the base chromosome number x = 7 (Anemone subgen. Anemonidium) as two genera, Hepatica sensu stricto and Anemonastrum in an expanded circumscription (including Anemonidium, Arsenjevia, Jurtsevia, and Tamuria). Following these conclusions, new nomenclatural combinations are proposed for two related species endemic to New Zealand and South America, respectively: Anemonastrum tenuicaule (= Anemone tenuicaulis, Ranunculus tenuicaulis) and Anemonastrum antucense (= Anemone antucensis). Information on typification is updated: the lectotype of Anemone antucensis is the specimen from P and not a specimen from G, and the lectotype of Ranunculus tenuicaulis is a specimen from AK. Biogeographic scenarios already proposed to explain the relationship of these two species and some other South America – New Zealand distribution patterns are discussed. It is concluded that the long-distance dispersal scenario fits best the available data for Anemonastrum. Two host-specific and geographically restricted species of Urosystis parasitizing A. tenuicaule and A. antucense are briefly discussed.

Infrageneric placement of the Southern Hemisphere taxa of Anemonastrum and Knowltonia earlier included in Anemone sensu lato (Ranunculaceae)

“…In our earlier articles (Mosyakin, 2016(Mosyakin, , 2018aMosyakin, de Lange, 2018, and references therein) we discussed extensively the problem of a rational circumscription of genera in the group of Anemone L. sensu lato (Ranunculaceae: Anemoneae). In general, in these articles we favored a rather narrow circumscription of genus-rank entities, with recognition of the following genera: (1) Hepatica Mill., (2) Anemonastrum Holub (including Anemonidium (Spach) Holub, Arsenjevia 2009; Mosyakin, 2018a), is morphologically rather diverse and, in our opinion, is in need of recognition of several morphologically and phylogenetically distinct infrageneric taxa.…”

“…Trans-Pacific biogeographical links and phylogenetic relationships of A. antucense and A. tenuicaule were discussed by Samuel (2000, 2001), Schuettpelz et al (2002), Ziman et al (2006Ziman et al ( , 2008, Meyer et al (2010), Hoot et al (2012), and some other authors. Information on taxonomy, nomenclature, morphology, and biogeography of A. tenuicaule and A. antucense was summarized in our earlier article (Mosyakin, de Lange, 2018…”

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“…In our earlier articles (Mosyakin, 2016(Mosyakin, , 2018aMosyakin, de Lange, 2018, and references therein) we discussed extensively the problem of a rational circumscription of genera in the group of Anemone L. sensu lato (Ranunculaceae: Anemoneae). In general, in these articles we favored a rather narrow circumscription of genus-rank entities, with recognition of the following genera: (1) Hepatica Mill., (2) Anemonastrum Holub (including Anemonidium (Spach) Holub, Arsenjevia…”

“…Consequently, if we follow the principles of phylogeny-based taxonomy not recognizing polyphyletic and paraphyletic taxa, we should either (1) unite Anemone sensu lato with Clematis sensu lato, with numerous new combinations needed and rather confusing nomenclatural and taxonomic outcomes, or (2) recognize several generic segregates from Anemone sensu lato, such as Anemonastrum, Hepatica, Knowltonia, Pulsatilla, Anemone sensu stricto (Mosyakin, 2016(Mosyakin, , 2018aMosyakin, de Lange, 2018;Christenhusz et al, 2018, and references therein), and probably also Eriocapitella Nakai (as recognized by Christenhusz and Byng in Christenhusz et al, 2018). The second option is preferred here and in our earlier publications (Mosyakin, 2016(Mosyakin, , 2018aMosyakin, de Lange, 2018), and is further justified and nomenclaturally implemented by Christenhusz and Byng (Christenhusz et al, 2018).…”