Adaptações morfoanatômicas de Cyperaceae ao ambiente aquático

Abstract

RESUMO -No ecossistema aquático há uma faixa de umidade gradiente no solo que interfere diretamente na ocupação das espécies à margem da lâmina de água. Essa zonação ecológica reflete os graus de adaptação que as plantas apresentam para tolerar o alagamento ou a dessecação. O presente trabalho visou apresentar a análise morfoanatômica de cinco espécies de Cyperaceae encontradas em diferentes zonas no entorno da represa Alagados, em Ponta Grossa-PR, Brasil: Cyperus giganteus, Rhynchospora corymbosa var. aspérula, Cyperus densicaespitosus, Cyperus rigens e Eleocharis sp. Estruturas caulinares e foliares das cinco espécies de Cyperaceae foram analisadas a partir de cortes histológicos. Concluiu-se que, das cinco plantas analisadas, somente três caracterizam-se como plantas aquáticas, sendo duas classificadas como plantas emergentes e uma como submersa fixa devido às características adaptativas que apresentam para obter sucesso nesse ambiente.Palavras-chave: anatomia caulinar, anatomia foliar, aerênquima, estresse.ABSTRACT -In the aquatic ecosystem there is gradient moisture in the soil that interferes directly in the occupation of species on the margin of the water blade. This ecological zone reflects the degrees of adaptation that plants present to tolerate flooding or drying. This work aimed to present a morphological and anatomical analysis of five species of Cyperaceae, found at different zones in the surroundings of the Alagados Dam, in Ponta Grossa-PR, Brazil: Cyperus giganteus and Rhynchospora corymbosa var. asperula, Cyperus densicaespitosus, Cyperus rigens and Eleocharis sp. Stem and foliar structures of five species of Cyperaceae were analyzed by histological cross-section. It was concluded that of the five plants examined, only three are aquatic plants, with two being classified as emerging plants and one as fixed submerged, based on the adaptive characteristics they present to succeed in this environment.

Importance of anatomical leaf features for characterization of three species of Mapania (Mapanioideae, Cyperaceae) from the Amazon Forest, Brazil

“…The leaf organs studied here also show anatomical characters associated to adaptation to humid, tropical forest environments as air lacunae, stomata at the same level or slightly above the other epidermal cells, and epidermal cells with sinuous wall and thin cuticles considered hydromorphic features (Pyykko 1966;Rocha and Martins 2011). However, all these features have already been reported in other Cyperaceae, independently of their phylogenetic position and habitat (Metcalfe 1971;Sharma and Mehra 1972;Alves et al 2002).…”

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

“…In allied species C. blepahroleptos, braciform cells also were observed in air lacunae [67]. The braciform cells provide structural support to air lacunae as well partake in the gas flow among distinct tissues of aquatic plants [67,[71][72][73][74][75][76].…”

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

“…Aerenchymatous tissue is common in aquatic and amphibious plants as a response to the anaerobic condition of the soil, and it is also commonly reported for Cyperacae (Fagerstedt ; Armstrong et al. ; Jackson & Armstrong ; Rocha & Martins ). Mapania macrophylla occurs in seasonally flooded areas, while M. pycnostachya occurs on river margins in Amazon forest and the presence of aerenchyma reflects the conditions to which these species are exposed.…”