Fruit Anatomy Provides Structural Synapomorphies to Help Define Myodocarpaceae (Apiales)

Fruit anatomical characters studied herein confirm the inclusion of Delarbrea and Myodocarpus in Apiales, but as a distinct group, corroborating previous studies (based on molecular data) in the recognition of Myodocarpaceae as a new family. The fruits of these generashare some features with those of Apiaceae (especially subfamilies Mackinlayoideae and Azorelloideae) and Araliaceae, including branchingand anastomosing vascular bundles and secretory canals, woody endocarps, the presence of single ventral bundles or carpophores, and dispersed crystals. However, the presence of median wings in Myodocarpus and secretory vesicles in the mesocarps (adjacent to the woody endocarp) in both genera are unknown in any other genus of the order. Fruit characters are also useful in distinguishing Delarbrea, which producesdrupes with a single ventral vascular bundle and sclereids in the mesocarp, from Myodocarpus, which has schizocarps with a single carpophoreand lacks sclereids. Delarbrea balansae, once treated as the sole member of Pseudosciadium, shares all the distinctive fruit features with the otherspecies of Delarbrea, further supporting its transfer there.