Abstract:
Romanschulzia guerrerensis, a new species from the State of Guerrero (Mexico), is described and illustrated. The new species resembles R. apetala, R. subclavata and R. rzedowskii in having apetalous flowers, but differs from the first two by having free instead of connate sepals and sessile instead of stipitate fruits. It resembles R. rzedowskii in the having free sepals, small anthers, and sessile, terete fruits, but differs in the erect-ascending vs. reflexed fruits and fruiting pedicels. It grows in a temperate and humid zone near cerro Teotepec in Guerrero. A key to the four species and a table comparing their various morphological characters are provided.