Systematic consideration of petiole anatomy of species of Echinodorus Richard (Alismataceae) from north-eastern Brazil

Petiole anatomy of the north-eastern Brazilian species Echinodorus glandulosus, E. palaefolius, E. pubescens, E. subalatus, E. lanceolatus and E. paniculatus were examined. All species had petioles with an epidermis composed of tabular cells with thin walls. The chlorenchyma just below the epidermis...

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Bibliographic Details
Authors: Matias, Lígia Queiroz, Soares, Arlete, Scatena, Vera Lúcia
Format: article
Status:Published version
Publication Date:2007
Country:Brasil
Institution:Universidade Federal do Ceará (UFC)
Repository:Repositório Institucional da Universidade Federal do Ceará (UFC)
Language:English
OAI Identifier:oai:repositorio.ufc.br:riufc/59067
Online Access:http://www.repositorio.ufc.br/handle/riufc/59067
Access Level:Open access
Keyword:Echinodorus
Alismataceae
Anatomy
Aquatic plants
Hydrophytes
Caatinga
Description
Summary:Petiole anatomy of the north-eastern Brazilian species Echinodorus glandulosus, E. palaefolius, E. pubescens, E. subalatus, E. lanceolatus and E. paniculatus were examined. All species had petioles with an epidermis composed of tabular cells with thin walls. The chlorenchyma just below the epidermis alternates with collateral vascular bundles. The interior of the petiole is filled by aerenchyma with ample open spaces or lacunas. The lacunas are bridged at intervals by plates, or by diaphragm-like linkages. There are lactiferous ducts and groups of fibres throughout the entire length of the petiole, but more frequently in the chlorenchyma. Important taxonomic characteristics for the genus Echinodorus include the shape and outline of the petiole in transversal section, the presence of winged extensions, and the number of vascular bundle arcs. Exceptions occur in E. lanceolatus and E. paniculatus, whose petioles have similar anatomic patterns. A comparative chart of the petiole anatomic characteristics analyzed is presented.