Taxonomic revision of Guichenotia (Lasiopetaleae: Malvaceae s.l. or Sterculiaceae)

Abstract

Taxonomic revision of the endemic Western Australian genus Guichenotia J.Gay identified 17 taxa, including seven previously recognised species and 10 new species, which are G. asteriskos C.F.Wilkins, G. astropletha C.F.Wilkins, G. basivirida C.F.Wilkins, G. glandulosa C.F.Wilkins, G. impudica C.F.Wilkins, G. intermedia C.F.Wilkins, G. quasicalva C.F.Wilkins, G. seorsiflora C.F.Wilkins, G. tuberculata C.F.Wilkins and G. anota C.F.Wilkins.

Cladistic analysis of morphological characters showed Guichenotia to be biphyletic with Guichenotia s.s., forming a clade that, although it has no bootstrap support, shares characters of 3–5 central prominent ribs on the outer surface of each calyx lobe, five carpels and petiolate bracts. G. apetala A.S.George and the closely related new species G. anota C.F.Wilkins ms form a strongly supported clade characterised by one central external rib on the outer surface of each calyx lobe, lobes with a rounded apex that are less than 40% of the total calyx length, leaves with prominent yellow venation on the adaxial surface, a tubular stigma with a rimmed pore where the apical 1/4 of the style is slightly wider than the base and no petals. These two clades are unresolved relative to Lasiopetalum by cladistic analysis of their morphology. Guichenotia s.s. is maintained as a genus, the species of which are revised here, pending clarification of its relationship to Lasiopetalum. The second clade will be described separately when the relationships of the Lasiopetalum–Guichenotia clade have been better resolved.

A key is presented for all species of Guichenotia s.l. Descriptions, distribution maps, illustrations and anatomical findings are presented for Guichenotia s.s.