Microgramma is a genus of ferns in the family Polypodiaceae (subfamily Polypodioideae), order Polypodiales. Commonly known as vine ferns or snakeferns, these small to medium-sized ferns are largely epiphytic — growing on the surfaces of trees in tropical forest canopies — though some species also grow as lithophytes on rocks. The genus is classified under the Pteridophyte Phylogeny Group system of 2016 (PPG I).
The genus has a broad tropical distribution spanning the Americas and Africa. Species are found from Mexico and the Caribbean through Central America and across South America, including Argentina and Brazil. The range extends to tropical and southern Africa and the western Indian Ocean islands, reflecting an ancient Gondwanan biogeographic history.
Microgramma was recircumscribed in 2008 based on phylogenetic evidence (Salino et al., Systematic Botany 33(4): 630–635), which refined the genus boundaries within Polypodiaceae. Earlier molecular phylogenetic work by Schneider et al. (2004) had already begun unraveling the relationships among polygrammoid ferns and highlighted the significance of epiphytic diversification within the family. The genus contains around 20–30 species, with GBIF recognising 6 accepted species in its backbone taxonomy.
Distribution
Microgramma species are native to tropical ecoregions across the Americas and Africa. The range spans Mexico, the Caribbean, Central America, and South America (including Argentina and Brazil), as well as tropical Africa, southern Africa, and western Indian Ocean islands.
Taxonomy Notes
Microgramma belongs to Polypodiaceae, subfamily Polypodioideae, and is placed in the order Polypodiales. Its current circumscription follows PPG I (2016) and was shaped by a 2008 phylogenetic revision (Salino et al., Systematic Botany) that adjusted the genus boundaries based on molecular evidence. Earlier phylogenetic work by Schneider et al. (2004) on polygrammoid ferns provided the broader framework for this reclassification.
