| Abstract: | Fusaea occurs in Colombia, Venezuela, the three Guianas, Ecuador, Peru, Brazi land Bolivia. It is found in non inundated and inundated rain forest at elevations from sea level to 600(-900)m. It is distinct from other related genera by its conspicuous ring of staminodes formed by the enlarged outer stamens, which is unique in the Annonaceae, and by an entirely fused calyx, combined with the fully syncarpous fruits with a basal collar. The general wood anatomical characters are in line with the very specific wood anatomy of the family, characterized by the tangential, concentric parenchyma bands. There is, however, one very specific feature in Fusaea : the small rhombic crystals in the ray cells. From the combined evidence from flower, fruit and pollen morphology, we can conclude that Fusaea is closely related to Duckeanthus, Duguetia, Pachypodanthium, Letestudoxa and probably Pseudartabotrys . Based on measurements of the diagnostic features on all the 158 available specimens identified either as F.longifolia or F.decurrens , we constructed three scatter diagrams to show the continuous variation of the distinguishing characters previously used. F.decurrens is obviously within the morphological variation range of F.longifolia , and is therefore brought into synonymy with the latter. Two species, i.e., F.longifolia and F.peruviana , are recognized in this genus. |
