Root, rhizome and scape anatomy of Amazonian species of Mapania Aubl. (Mapanioideae, Cyperaceae) and its taxonomic and ecological significance

Abstract

Cyperaceae are a cosmopolitan Monocot family comprising about 5,700 species divided into two subfamilies: Cyperoideae and Mapanioideae. Within Mapanioideae, Mapania is the largest genus, with about 90 species. Anatomical studies on Mapanioideae are of great importance but still scarce. Here, the anatomy of roots, rhizomes and scapes of five Amazonian species of Mapania is studied. The species have two types of roots, which differ anatomically: thick roots, serving mainly for fixing, and thin ones, mainly for nutrient absorption. Rhizomes show a uniform anatomical pattern, with amyloplasts and phenolic idioblasts in the cortex and in the vascular cylinder, without aerenchyma. In this organ, the collateral vascular bundles are similar to those found in Hypolytrum, a genus closely related to Mapania within Mapanioideae, suggesting that this feature may be diagnostic for the tribe Hypolytreae. The scape anatomy of the species is taxonomically important at species level but does not corroborate precisely the infrageneric classification of the genus. Finally, the aerenchyma found in roots and scapes is an adaptive character state for a humid forest environment. This work contributes valuable information for the anatomical characterization of vegetative organs of Mapania and discusses its taxonomic and ecological relevance.

Synopsis of the genus Mapania (Cyperaceae, Mapanioideae, Hypolytreae) in the Colombian Amazon

“…Mapania pycnostachya also represents a novel addition to the Colombian Amazon flora. While previously documented in the Pacific lowlands by Bernal et al (2016), this species is naturally tied to Amazonian forests (Kearns et al 1998, Simpson 2006, Silva et al 2019. The earlier report is likely a result of mistaking M. pycnocephala for M.…”

“…Among these, five are distributed in the Amazon, rendering this region the most diverse for the genus in the country.The remaining trio of Colombian species (M. assimilis, M. cuatrecasasii and M. sylvatica) is predominantly situated in the Pacific region(Bernal et al 2016, GBIF 2023, speciesLink 2023.The Colombian species of Mapania are important elements of the understory vegetation and riverbank environments within the Amazon and Chocó biogeographic regions. Their ability to diversify in the prevailing humid conditions of these areas can be attributed to their specialized morphoanatomical features(Silva et al 2019). In the Colombian Amazon most of the species occur in forests and hills along the Apaporis River basin.…”

Cyperus prophyllatus: An endangered aquatic new species of Cyperus L. (Cyperaceae) with a exceptional spikelet disarticulation pattern among about 950 species, including molecular phylogenetic, anatomical and (micro)morphological data

“…The new species shows other anatomical characteristics observed in C 3 Cyperus Grade as a colorless parenchyma surrounding the vascular bundles and large air lacunae immerse in chlorophyll parenchyma in mesophyll tissue [64,66,67]. The air lacunae make survival in aquatic environments possible, since it promotes oxygen flow from leaves to submerged organs [68][69][70]. In allied species C. blepahroleptos, braciform cells also were observed in air lacunae [67].…”