Abstract
We describe and illustrate Wahlenbergia itatiaiensis, a new species of Campanulaceae, endemic to the Itatiaia National Park in the Atlantic Forest (Brazil). The new species is compared with W. linarioides, the sympatric and morphologically most similar species, and to W. intermedia. Wahlenbergia itatiaiensis is mainly distinguished by the linear to lanceolate leaves with few, short denticles along the margin, 3-locular ovary, and 3-lobed stigma. An identification key for these species is provided. The new species occurs on sandy and rocky, wet soils, adjacent to dirt roadsides of the upper part of the National Park. Detailed comments on the distribution and conservation status, as well as details of morphological variation and photographs are provided.