Cojoba
Seed, cotyledon, embryo, and testa:
C. arborea (C. Linnaeus) Britton & J.N. Rose - testa SEMs; C
. donnell-smithii Britton & J.N. Rose - bottom left testa topography;
C. rufescens (G. Bentham) Britton & J.N. Rose - top left cotyledons concealing radicle (L) and embryonic axis (R); C. spp. - bottom left center seeds.