Achene Morphology and Pericarp Anatomy of the Type Specimens of the Australian and New Zealand Species of Bolboschoenus (Cyperaceae)

Abstract

Three species of Bolboschoenus (Ascherson) Palla are reported for Australia and New Zealand. Bolboschoenus caldwellii (V.J.Cook) Soják and B. medianus (V.J.Cook) Soják are based on types from New Zealand (under Scirpus L.). Bolboschoenus fluviatilis (Torrey) Soják has been lectotypified by a specimen from North America. Scirpus perviridis V.J.Cook, the type of which is also from New Zealand has been considered conspecific with Bolboschoenus fluviatilis. Achene morphology and pericarp anatomy of achenes removed from isotypes of Cook’s three species, Scirpus perviridis, S. caldwellii and S. medianus, are described and illustrated by electron micrographs. These achenes are compared with a representative sample of achenes of each of the Bolboschoenus species named above, taken from herbarium specimens collected in Australia and New Zealand. Infraspecific taxa within Bolboschoenus fluviatilis are briefly outlined. Features of Bolboschoenus medianus suggest a possible hybrid origin.