The American spicate cudweeds adventive to New Zealand: (Gnaphalium section Gamochaeta—Compositae)

Abstract

Eight American cudweeds belonging to Gnaphalium section Gamochaeta are adventive to New Zealand. They are G. calviceps Fern., G. subfalcatum Cabr., G. pensylvanicum Willd., G. simplicicaule Willd. ex Spreng., G. purpureum Linn., G. ustulatum Nutt., G. spicatum Lam., and G. americanum Mill. Keys to cudweed groups and Gnaphalium sections, as well as to these adventive species, are provided together with species descriptions, nomenclatural summaries, habitats, and distributional records, and observations.