The Occurrence of a Secondary Cuticle in Libertia elegans (Iridaceae)

Abstract

A study of the formation of cuticle in Libertia elegans has shown that the cuticle develops centripetally and is produced continuously at its juncture with the underlying pectic layer. Peroxidase activity may be demonstrated in this region during development. Growth occurs in two discrete phases; initially whilst the underlying epidermal cells are expanding and later when such expansion is complete. The phases are morphologically distinct and it is proposed that the terms primary and secondary be applied to them. Cuticular channels with a pit-like appearance in T.S. are described here for the first time as is the fissuring and active replacement of inelastic secondary cuticular material to accommodate costal expansion and the growth of papillae.