Morphology and vascular system of the inflorescences of Mollugo nudicaulis Lam. and Hypertelis bowkeriana Sond. (Molluginaceae)

The variation in build and vascular anatomy of the inflorescences of Mollugo nudicaulis Lam, and Hypertelis bowkeriana Sond. is examined, in living and herbarium material and in serial transverse sections. The ‘umbel’ of H. bowkeriana may be thought to be derived from an inflorescence like that of M. nudicaulis (a primitive type within the Molluginaceae) by suppression of internodes and reduction. Whereas the inflorescential structure of both species is rather constant, the vasculature of the younger inflorescential branchings ( H. bowkeriana), or that of the younger basal ramification and the branchings in the partial inflorescences (M. nudicaulis), shows a certain amount of plasticity, the general idea being that of a system of distribution of a limited amount of material. ‘Opportunism’ vs. ‘conservatism’ of vascular bundles is discussed.