[Calcium oxalate crystals in several kinds of Cinnamon bark].

OBJECTIVE: To probe into the morphology and distribution characteristics of calcium oxalate crystals in several kinds of Cinnamon bark. METHOD: Forty samples of ten different species of Cinamomi Cortex were examined, and the inter-cellular calcium oxalate crystals in the phloem rays were observed by optical microscope and scanning electron microscope. RESULT: It was found that for samples of the same botanical origin, there is little variation in the crystal morphology following certain regularity. The amount, size and ultra-micromorphologic characteristics are influenced by various factors. CONCLUSION: The pattern of morphology and distribution of calcium oxalate crystals may well be an index for identification of the crude drug of Cinnamon bark.