Legume species had the same nodule structure to the legume crops , which was cortex , vascular bundle and bacteriocyte area . But some special nodule cambial cells were found in cortex , which was related to the nodule cassation and differentiation of vascular bundle to some extend .

豆科树种根瘤具有豆科植物根瘤的基本结构，即从外向内依次为皮层、维管束和含菌细胞区，但在皮层中发现有特殊的根瘤形成层细胞，可能与根瘤增粗及根瘤维管束的分化形成有关。