First description of extrafloral nectaries in Opuntia robusta (Cactaceae): Anatomy and ultrastructure
Fig 2
Areole of young cladode of Opuntia robusta.
(A) Young areola with extrafloral nectary (efn, arrow) behind a persistent leaf, showing a drop of nectar (close up at the corner); (B) Ant collecting nectar from the extrafloral nectary; (C) and (D) Extrafloral nectary is a modified spine with an apical secretory cone (asc); (E) Distribution of the areola components and diagram. asc–apical secretory cone; efn: extrafloral nectary; lf—leaf; s—lateral spines; sp—central spine; tr—trichomes. (A) and (B)–bar = 2 mm, (C) and (D)–bar = 1mm, (E)–bar = 3 mm.