Intranuclear crystalloids in leaves and styles of Linaria vulgaris mill

Unusual intranuclear inclusions present in the parenchymatic cells of leaves and styles of Linaria vulgaris are described. These inclusions are composed of layers of tubules spaced 9–10 nm apart. The direction of the tubules in each layer is offset 60° with respect to the tubular direction in the adjacent layers. The diameter of the tubules (23–26 nm) suggests a similarity to the cytoplasmic microtubules. The high degree of molecular order in these structures allows discrete optical diffraction to 7 nm. These intranuclear microtubular crystalloids, as already reported for other such crystalloids, have close associations with the nucleoli.