Impatiens elianae (Balsaminaceae), a new species from central Madagascar, with notes on the taxonomic relationship of I. lyallii and I. trichoceras

The new species Impatiens elianae is described from cultivated plants said to have been collected in central Madagascar. It is part of the I. lyallii complex and closely related to I. trichoceras from eastern central Madagascar, but differs in having a glossy lamina with silvery part in the centre, linear extrafloral nectaries, 2-flowered inflorescences, relatively long hairs (0.8–1.2 mm) on the sepals, larger size and shape of the broad ovate crest at the dorsal side of the dorsal petal, shorter spur, and (3–) 5 rows of pink hairs on the ovary and fruit. Impatiens trichoceras is taken from the synonymy of Impatiens lyallii and is considered as a species of its own.