Ongoing research on the taxonomically complex genus Cheilanthes (Pteridaceae; Cheilanthoideae) has resulted in the identification of a new species from Loja Province in Ecuador, Cheilanthes ecuadorensis, described and illustrated herein. Originally collected in 1988 and identified as C. cf. rufopunctata, C. ecuadorensis is clearly distinct from that species in having pubescent adaxial blade surfaces and narrow, poorly-differentiated false indusia (rather than the glabrous adaxial surfaces and wide false indusia of C. rufopunctata). Among the South American species currently included in Cheilanthes, C. ecuadorensis is superficially most similar to C. pilosa. However, our molecular phylogenetic analyses indicate that C. ecuadorensis is sister to C. micropteris, the morphologically disparate generitype of Cheilanthes. Here we examine the phylogenetic relationships, morphology, cytogenetics, and geography of these four South American Cheilanthes species in a study that, once again, highlights the importance of herbaria in the process of new species discovery.