Wood anatomy of Craigia (Malvales) from Southeastern Yunnan, China.

摘要

The wood anatomy of Craigia (Malvaceae s.l.) from southeastern Yunnan Province, a tree endemic to China and Vietnam, is described in order to provide new characters for assessing its affinities relative to other malvalean genera. Craigia has very low-density wood, with abundant diffuse-in-aggregate axial parenchyma and tile cells of the Pterospermum type in the multiseriate rays. Although Craigia is distinct from Tilia by the presence of tile cells, they share the feature of helically thickened vessels - supportive of the sister group status suggested for these two genera by other morphological characters and preliminary molecular data. Although Craigia is well represented in the fossil record based on fruits, we were unable to locate fossil woods corresponding in anatomy to that of the extant genus..