Phylogeny of the Hyperdiverse Cariceae + Dulichieae + Scirpeae S.S. Clade (Cyperaceae)

JULIAN R. STARR; CLAIRE N. GILMOUR ; ROBERT F. C. NACZI ; SABINA DONADÍO; ÉTIENNE LÉVEILLÉ-BOURRET; BRUCE A. FORD; DANIEL SPALINK; KENNETH SYTSMA

Nueva York

Conferencia; MONOCOTS V: 5th International Conference on Comparative Biology of Monocotyledons.; 2013

The New York Botanical Garden & Fordham University

Over the past 50 years, evidence from embryo types, fruit epidermal silica bodies, and morphological and molecular phylogenies has indicated that the sedge genus Scirpus s.l. (200-300 spp.) is polyphyletic. Although many of the genera segregated from Scirpus s.l. are clearly distantly related to Scirpus s.s. (e.g. Isolepis, Schoenoplectus), others, such as Eriophorum or Trichophorum, cannot be easily delineated from Scirpus and their relationships remain unclear owing to a series of intermediate taxa (e.g., Scirpus maximowiczii, Eriophorum scabriculme). In addition, the relationships of these genera within a wider clade consisting of tribes Scirpeae s.s., Dulichieae, Cariceae, and the monotypic genus Khaosokia, are still unresolved. Using the cpDNA genes matK and ndhF our results suggest there are five major lineages sister to Khaosokia with tribe Dulichieae being sister to all these lineages within the Cariceae + Dulichieae + Scirpeae s.s. clade. Molecular and embryo type analyses suggest that a Trichophorum + Oreobolopsis + Cypringlea clade or the recently discovered genus Calliscirpus may be sister to tribe Cariceae. The possible existence of another new genus is currently under study. MatK + ndhF analyses suggest that Eriophorum s.s. is strongly monophyletic (93% BS) and nested within Scirpus s.s. clade that includes S. maximowiczii, but support is low (< 63% BS). However, intensive sequencing of both single-copy nuclear genes (ZCD, APEP, PHYC) and four additional chloroplast markers provides strong evidence that Eriophorum s.s. and Scirpus s.s. are inseparable.