No secondary growth in stems of the dicotyledon Ranunculus

Buttercup (Ranunculus sp.) is a primitive dicotyledonous herb lacking secondary growth. Its vascular bundles are of closed type and similar to those of monocotyledons. It has a typical eustele, but the bundles are not fully differentiated inasmuch as they do not possess a vascular cambium. Notice the irregular band of fibers in the interfascicular regions at the level of primary xylem, and the sclerenchyma caps over the primary phloem.