WOOD ANATOMY OF TWO SPECIES OF THE GENUS Heterothalamus Lessing (ASTERACEAE) FROM RIO GRANDE DO SUL (BRAZIL)

Abstract

The present work describes the wood anatomy of Heterothalamus alienus and Heterothalamus rupestris (Astereae - Asteraceae), as part of the secondary xylem study in the named genus. For the two species it was recorded some features usually mentioned in the literature for the Asteraceae, as typically small vessels, grouped in a dendritic pattern, the presence of only simple perforation plates and of paratracheal parenchyma. Heterothalamus alienus shows spiral thickenings in the wood vessels and storied vasicentric axial parenchyma. Heterothalamus rupestris differs itself by the absence of spiral thickenings in wood vessels and by no storied axial parenchyma, in paratracheal vasicentric to unilateral patterns. Photomicrographs, quantitative data of anatomical features and a comparison between the two species of wood are also provided.

Keywords

• Asteraceae
• <i>Heterothalamus alienus</i>
• <i>Heterothalamus rupestris</i>
• anatomia da madeira