Abstract: Using the pollen and leaves of Heteroplex Chang as the materials,scanning electron microscopy （SEM） was used to observe and analyze its micromorphological characteristics. The results showed that the pollen grains of H.microcephala, H.vernonioides, H.impressinervia and H.incana were subglobose, and H.sericophylla was prolate. There were obvious thorn prominence on the outer wall of the pollen of the five species, the thorn length and the base diameter of H.microcephala and H.sericophylla were the large, H.impressinervia and H.incana had no glandular hairs or appendages on the adaxial epidermis. H.sericophylla had longer and denser glandular hairs in the adaxial epidermis, while H.microcephala and H.vernonioides had appendages. The epidermis ornamentation of the leaves of Heteroplex was concentrated around the stomatal apparatus in a radial shape, the stomatal apparatus was elliptical, and the internal ornamentation was shallow wavy. There were no appendages or glandular hairs in the abaxial epidermis of H.microcephala, while emulsus appendages were distributed in the abaxial epidermis of H.vernonioides. Glandular hairs were distributed in the epidermis of H.impressinervia, H.incana and H.sericophylla. The micromorphological characteristics of the leaf surface showed good interspecific differences.

Key words: Heteroplexis Chang, leaf epidermi characters, stomatal characters, pollen characters, taxonomy