Pollen morphology, phytogeography, and phylogeny of the Annonaceae

Disentangling lianas : The systematics of Monanthotaxis (Annonaceae)

“…Phylogenetic studies (Bygrave 2000, Couvreur et al 2011, Richardson et al 2004) have consistently placed Dasymaschalon and Friesodielsia in a wellsupported subclade of tribe Uvarieae (referred to here as the "Dasymaschalon alliance"), together with two other genera, Desmos and Monanthotaxis. This close relationship is corroborated by several diagnostic characters, including the glaucous abaxial surface of the leaves (Wang et al 2012), inaperturate pollen with echinate-microbaculate ornamentation (Bygrave 2000, Doyle & Le Thomas 2012, Le Thomas 1980, Le Thomas 1981, Walker 1971b, and monocarps (when multi-seeded) with distinct constrictions between neighbouring seeds (Wang et al 2012). As is generally the case in Annonaceae, however, these characters show homoplasies or reversals and therefore are not found in all species in the Dasymaschalon alliance.…”

“…The polyphyletic status of Friesodielsia, in which the African species are not congeneric with the Asian species, was previously indicated by palynological data (Walker 1971b) and molecular phylogenetic analyses (Chatrou et al 2012, Couvreur et al 2011.…”

“…1G, I-K), petals that are wide and short and pollen with a microbaculate exine; whereas species in Clade II have flowers with partially enclosed floral chambers, petals that are narrow and elongate (Fig. 1A, C, E) and echinate-scabrate pollen (Saunders 2010, Verdcourt 1971, Walker 1971b, Wang et al 2009.…”

“…Palynological data also indicate that Friesodielsia is heterogeneous, with Asian species possessing pollen with anechinate exine, whereas some African species (F. gracilipes (Benth.) Steenis and F. discostigma (Diels) Steenis) have coarsely verrucate pollen (Walker 1971b). Verdcourt (1971) Verdcourt (1971) also noted that the two small African subgenera (subg.…”

“…In addition to the African species of Friesodielsia, the monospecific genera Exellia Boutique and Gilbertiella Boutique also appear to be closely related to Monanthotaxis. The taxonomic status of these two genera has been unclear, although they have been grouped with Monanthotaxis based on flower and pollen morphology (Le Thomas 1981, Van Heusden 1992, Walker 1971b). Gilbertiella has also been classified in the same group as Monanthotaxis based on fruit and seed morphology (Van Setten & Koek-Noorman 1992), while Exellia has very distinct fruits, comprising sessile biseriate monocarps, in contrast to the stipitate uniseriate monocarps in Monanthotaxis and Gilbertiella.…”