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.