Stomata in Dacrydium (Podocarpaceae)

Cuticle micromorphology of herbarium and of preserved leaves of four species of the genus Dacrydium was studied with scanning electron microscopy.

Dacrydium araucarioides, D. balansae, D. guillauminii, and D. lycopodioides from New Caledonia are all representatives of the tropical subgroup of the genus.

External and internal features of abaxial and adaxial cuticles are characterized for all taxa. External cuticle surfaces of all species lack the Florin rings present in other members of the Podocarpaceae.

Sunken stomata in discontinuous rows characterize all taxa. Subsidiary cell number varies from two to five. Epidermal cell outlines are very sinuous, and cuticle from cell surfaces is smooth to slightly pitted.

Cuticle on guard cell surfaces distinguishes the taxa. Micromorphological features are compared with other previously studied genera in the Podocarpaceae. The New Caledonian species of the genus Dacrydium show a close similarity to each other in micromorphological features of leaf cuticle and are easily distinguishable from other podocarp genera.