Taxonomic revision of five species groups of ebracteate-erect Myosotis (Boraginaceae) endemic to New Zealand, based on morphology, and description of new subspecies

Abstract

Macro-morphological data were analysed to assess the distinctiveness and revise the taxonomy of 14 species, varieties and tag-named taxa in five informal species groups of ebracteate-erect forget-me-nots endemic to New Zealand. The following nine species are recognised: Myosotis albosericea Hook.f., M. brockiei L.B.Moore & M.J.A.Simpson, M. capitata Hook.f., M. concinna Cheeseman, M. goyenii Petrie, M. laeta Cheeseman, M. monroi Cheeseman, M. rakiura L.B.Moore, and M. traversii Hook.f. Three species have two allopatric subspecies each in the South Island, distinguished by few, minor morphological characters, including Myosotis brockiei subsp. brockiei and M. brockiei subsp. dysis Courtney & Meudt subsp. nov., M. goyenii subsp. goyenii and M. goyenii subsp. infima Meudt & Heenan, and M. traversii subsp. cantabrica (L.B.Moore) Meudt comb. et stat. nov. and M. traversii subsp. traversii. Myosotis × cinerascens Petrie is hypothesised to be a rare natural hybrid involving M. traversii subsp. cantabrica and another species, possibly M. colensoi. Several vegetative and floral characteristics can distinguish the study taxa from one another and from other ebracteate-erect species. The nine species plus M. × cinerascens are included in the taxonomic treatment, and the key also includes other recently revised ebracteate-erect species.