Holoparasitic and mycoheterotrophic plants from the municipality of Igarapé-Miri, Pará, Brazil: Balanophoraceae Rica., Burmanniaceae Blume, Orchidaceae Juss. and Triuridaceae Gardner

Amazon, Floristic, Achlorophyllous plants, Taxonomy

The holoparasitic plants and mycoheterotrophic compose groups of plants rarely collected and less expressive in the Brazilian flora. In Pará state, only 27 species are registered, and  there are only five works that deal with these groups of plants floristic and taxonomically. The state suffers serious environmental damage from deforestation, but some regions still have areas practically unchanged, such as the municipality of Igarapé-Miri, considered one of the largest producers of açaí in the world. Because of this, the floristic diversity of holoparasitic and mycoheterotrophic plants can be strongly affected. What motivated this study before the local extinction of these groups of plants occurs, without having their species cataloged. For this, a survey was initially carried out in the herbaria and in the database platforms of the herbariums. Once this was done, expeditions were carried out to collect botanical material from January/2022 to January/2023, two per month. All species found were photographed in their natural habitat and weeded in the usual ways, with some modifications for better packaging and subsequent analysis of the collected material. The flora of holoparasitic and mycoheterotrophic plants in the municipality of Igarapé-Miri, belonging to the families Balanophoraceae, Burmanniaceae, Orchidaceae and Triuridaceae is represented by 11 species, distributed in 9 genera. Balanophoraceae was the only family that presented a holoparasite species (Helosis cayanensis (Sw.) Spreng. var. cayanensis), the others were all mycoheterotrophic being Burmanniaceae the most representative with six species: Apteria aphylla (Nutt.) Barnhart ex Small; Dictyostega orobanchoides subsp. parviflora (Benth.) Snelders & Maas; Gymnosiphon breviflorus Gleason; Gymnosiphon divaricatus (Benth.) Benth. & Hook. f.; Gymnosiphon saccatus (Sandwith) Merckx; Hexapterella gentianoides Urb.