Cuticle development on bladder primordium of Utricularia lateriflora. Click diagram to se the homogeneous electron-dense procuticle at A to C and the development of a lamellate cuticle proper at D to F.

Heide-Jørgensen H S, 1991. Cuticle development and ultrastructure: evidence for a procuticle of high osmium affinity. - Planta 183: 511-519.

Transmission electron microscopy was used to investigate the development and ultrastructure of the cuticles of the bladder primordium and other parts of Utricularia, the stem of Cuscuta gronovii, and the leaves of Athanasia parviflora. In all materials investigated, except the apical meristem of Cassytha pubescens, the first formed cuticle, named the procuticle, was very electron dense and apparently amorphous in texture. Later, the procuticle changed its ultrastructural appearance: in all species having a procuticle it lost much of its electron density. Simultaneously, it developed into a lamellar structure in U. lateriflora and Cuscuta, and became part of a lamellar cuticle proper. In U. sandersonii and Athanasia the procuticle generally remained without visible structure. The velum of the pavement epithelium of Utricularia is considered to be a slightly modified procuticle which has become loosened from the epithelial cells and stretched.

Key words: Athanasia - Cassytha - Cuscuta - Cuticle (development, ultrastructure) - Procuticle - Utricularia - Velum

According to Källersjö, M. 1986 - Nord. J. Bot. 5: 527-542, the correct name for Athanasia parviflora is Hymenolepis parviflora (L.) D. C.