Impatiens marroninus, a new species of Impatiens (Balsaminaceae) from Sumatra, Indonesia

Impatiens marroninus Utami (Balsaminaceae), collected from Sumatra, Indonesia, is described and illustrated as a new species. The species belongs to subg. Impatiens sect. Kathetophyllon. It is characterized by opposite or whorled leaves, yellow flowers with red maroon stripes in the upper part of the two lateral petals, dark green leaves and the lower sepal deeply navicular and constricted into a short curved spur. This combination of morphological characters was previously unknown. Detailed description, illustration, phenology, IUCN conservation assessment and ecology of the species are provided.