Evidence from fruit structure supports in general the circumscription of Apiaceae subfamily Azorelloideae

The fruit anatomy of 51 species of Apiaceae, representing all 23 genera of the traditional tribe Mulineae (now recognized as Apiaceae subfamily Azorelloideae) and their putative relatives, was studied in detail. Most genera (Asteriscium, Azorella, Bolax, Bowlesia, Dichosciadium, Dickinsia, Diplaspis, Diposis, Domeykoa, Drusa, Eremocharis, Gymnophyton, Hermas, Homalocarpus, Huanaca, Laretia, Mulinum, Oschatzia, Pozoa, Schizeilema and Spananthe) have a combination of woody endocarps with the innermost layer of fibers arranged longitudinally and fruits that are either isodiametric or dorsally compressed (never laterally compressed), with lateral ribs or wings that are usually larger than all other ribs or wings. This combination of anatomical characters is unique to most of subfamily Azorelloideae. Choritaenia, and Klotzschia, however, lack prominent lateral ribs or wings, and also differ in other anatomical features, suggesting the exclusion of these taxa from the Azorelloideae. Carpological characters were found to be helpful in refining the circumscription of the subfamily.