There are seven endemic species of Boswellia Roxb. ex Colebr. on Socotra Island, Yemen. Boswellia socotrana Balf. f. is a culturally, economically, and ecologically important species on the island. The name Odina aspleniifolia Balf. f. has been considered as a synonym, but there are morphological differences between the two taxa sufficient to justify their distinction at subspecific rank. Therefore, O. aspleniifolia is transferred to Boswellia as B. socotrana subsp. aspleniifolia (Balf. f.) Lvončik. A lectotype is designated for O. aspleniifolia. The distribution and ecology of both subspecies are discussed, as is their conservation status.