Spathiphyllum pygmaeum from Ecuador is described as a species new to science and illustrated. Only 10–15 cm tall, it is the smallest species in the genus and it is characterised by leaf blades 7–10 cm long and c. 2 cm wide, with 3–5 primary lateral veins on
each side of the midrib, a white spathe with green apex and a two-locular ovary with one ovule in each locule; the chromosome number is 2n = 30; the pollen, formerly considered as inaperturate for Spathiphyllum, is actually polyaperturate. It is compared with the closely related
S. minor, which is also illustrated.
Willdenowia is an international peer-reviewed journal publishing original research papers in English from the entire fields of plant, algal and fungal systematics, covering the evolution, taxonomy and nomenclature of these organisms as well as related fields such as floristics and plant geography. Three issues appear each year (in April, August and December) in an open-access online edition and a print edition. Individual papers may be published in the online edition as fast-track articles ahead of inclusion in these issues.