BELOW THE SURFACE. “General appearance and size also belie very different tissue constructions and developmental capacities. The non-vascular blade-stipe-holdfast architecture of some marine brown algae is constructed with an intercalary meristem (e.g. Agarum and Macrocystis) and yet is remarkably similar to the leaf-stem-root configuration of the vascular land plants.”
http://aob.oxfordjournals.org/content/85/4/411.full.pdf