Comparative wood anatomy of vegetative organs (stem and rhizome) of Sophora linearifolia (Sophoreae, Papilionoideae, Leguminosae)

Abstract

Wood anatomy of stem and rhizome of Sophora linearifolia, a rhizomatous plant endemic to centre Argentina, is described. Structural description of thin sections and macerations includes microphotographs of optical and scanning electron microscopy. Significant anatomical differences exist between secondary xylem of aerial orthotropic shoots and underground rhizome. Both organs have absent to indistinct growth ring boundaries, simple perforation plates, alternate and vestured intervessel pits and disjunctive parenchyma cell walls. However, stems have smaller vessels, longer fibres, partial storying (vessel elements and axial parenchyma) and narrower rays. Some anatomical characters of the rhizome suggest adaptations to its sinuous pattern of growth. The stem wood anatomy indicates a close relationship to Sophora sect. Edwardsia.