Species of Apocynaceae stand out among angiosperms in having very complex fl owers, especially those of asclepiads, which belong to the most derived subfamily (Asclepiadoideae). Th ese fl owers are… Click to show full abstract
Species of Apocynaceae stand out among angiosperms in having very complex fl owers, especially those of asclepiads, which belong to the most derived subfamily (Asclepiadoideae). Th ese fl owers are known to represent the highest degree of fl oral synorganization of the eudicots, and are comparable only to orchids. Th is morphological complexity may also be understood by observing their glands. Asclepiads have several protective and nuptial secretory structures. Th eir highly specifi c and specialized pollination systems are associated with the great diversity of glands found in their fl owers. Th is review gathers data regarding all types of fl oral glands described for asclepiads and adds three new types (glandular trichome, secretory idioblast and obturator), for a total of 13 types of glands. Some of the species reported here may have dozens of glands of up to 11 types on a single fl ower, corresponding to the largest diversity of glands recorded to date for a single structure.
               
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