Recently Namboodiri and Beck (1968c) and Beck (1970) in proposing a new hypothesis of stelar evolution in the gymnosperms failed to mention its possible application to angiosperms. This paper, by showing the close similarity of the primary vasculature of gymnosperms with that of the ‘parastichous type’ (Philipson and Balfour, 1963) in dicotyledons, shows that the hypothesis applies equally to both groups. Brief reference is made to other instances of stelar structure where application of the leaf-gap theory (Jeffrey, 1902, 1917) has failed. Here Namboodiri and Beck's new concept, that parenchymatous areas may arise having no association with leaf gaps, is most helpful.