Cuticle micromorphology of Podocarpus, subgenus Podocarpus, section Scytopodium (Podocarpaceae) of Madagascar and South Africa

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 characte rized for all taxa and are compared with other known Podocarpus species. Ex ternal cuticles exhibit Florin rings and stomatal plugs with underlying epi dermal cell outlines usually visible. Leaves are hypostomatic and stomata o ccur in discontinuous but fairly regular rows in most species. Stomata are oriented parallel to the long axis of the leaf and usually lack polar subsi diary cells. From two to six subsidiary cells occur, with two or three bein g 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 species. Epidermal cell outli nes are undulating and cuticle on epidermal cell surfaces is granular to ru gose and pitted. The most useful characters to distinguish species of this section are the micromorphology of cuticle on the guard cell and subsidiary cell surfaces, epidermal cell shapes, and sometimes the length of polar ex tensions.