Cuticle Micromorphology ofPodocarpus, SubgenusPodocarpus, SectionScytopodium(Podocarpaceae) of Madagascar and South Africa

Abstract

Cuticle micromorphology of leaves from seven species and three varieties of the conifer genus Podocarpus subgenus Podocarpus section Scytopodium from South Africa and Madagascar was studied with scanning electron microscopy. External and internal features of abaxial and adaxial cuticles are characterized for all taxa and are compared with other known Podocarpus species. External cuticles exhibit Florin rings and stomatal plugs with underlying epidermal cell outlines usually visible. Leaves are hypostomatic and stomata occur in discontinuous but fairly regular rows in most species. Stomata are oriented parallel to the long axis of the leaf and usually lack polar subsidiary cells. From two to six subsidiary cells occur, with two or three being the most common. Internal cuticle on subsidiary cell surfaces is granular to rugose, usually with a deep groove corresponding to the external Florin ring. Cuticle on guard cell surfaces is granular or rugose to pitted, and prominent polar extensions are present in all...