New taxa and notes on 'Helicteres' L. (Malvaceae: Helicteroideae) from the Northern Territory, Australia

Six new species and a new subspecies of Helicteres from the wet - dry tropics of the Northern Territory, Australia are described and illustrated (H. darwinensis, H. kombolgiana, H. macrothrix, H. serpens, H. sphaerotheca, H. tenuipila and H. cana subsp. latifolia). Methorium integrifolium is reinstated as a species and a new combination is made in Helicteres (H. integrifolia) to accommodate it, while Helicteres dentata is reduced to subspecific level under H. integrifolia. Two varieties of H. dentata are raised to specific level (H. procumbens and H. flagellaris). A key to the 13 species known from the Northern Territory is provided and variation in some widespread taxa is discussed.