| ||||||||||||||||||||
Unusual root branching in the riverweed family
Podostemaceae, aquatic angiosperms that grow on water-worn rocks in waterfalls and rapids, have diversely structured roots. Hiyama et al. (pp. 735-744) show that in Zeylanidium not only do subcylindrical and ribbon-like roots branch exogenously by means of meristem splitting, but so too do foliose roots. This arises from the arrest of a part of the apical or marginal meristem under the influence of the root-borne adventitious shoots.
| ||||||||||||||||||||