Identification of Cinnamomum osmophloeum and C. burmannii by Morphological Character and Essential Oil Character

In order to identify the morphological characters and the essential oil properties of Cinnamomum osmophloeum and C. burmannii, this study was carried out in a multi-division and multi-didiscipline way. Experimental materials were investigated and collected from different places in Taiwan to identify the morphological characters and to analyze their contents.
The morphological similarity between C. osmophloeum and C. burmannii makes it very difficult to morphologically identify them. The leaf size and shape of C. osmophloeum varies largely and larger than C. burmannii and, thus, makes the comparison impossible. However, the branchlets of C. osmophloeum are pale green and their leaves are leather-like with pale green on surface and grayish white underneath. The branchlets of C. burmannii are red and their leaves are paper-like with dark green on surface and pale green underneath. Therefore these properties, especially in seedling stages, could be used for identification purposes. In addition, the tip of the persistent sepals on C. burmannii is truncate and that of C. osmophloeum is fully preserved. This is another important identification character.
Essential oils were determined by steam distillation from leaves collected from 58 planted trees from different places mentioned earlier. The chemical contents of the essential oils were then analyzed by GC, GC/MS (Gas Chromatography-Mass Spectrometry) and confirmed by principal component analysis (PCA). The major contents of C. osmophloeum essential oil are trans-cinnamaldehy, benzaldehyde, geranyl acetate, cinnamyl acetate, and cinnamyl alcohol. However, the essential oils of C. burmannii can be categorized into 6 types due to the difference of major contents: (1)Linalool type; (2)1,8-cineole type; (3)1,8-cineole/α-phellandrene type; (4)1,8-cineole/p-cymene type; (5)borneol type; (6)borneol/1,8 cineole type: and (7)cinnamaldehyde type. This last type is a new research finding.
It is very applicable using morphological characters and the fragrance of essential oils to identify these two species. In order to produce special products, using silvicultural model and data bank to correctly select good seedlings is beneficial to sustainable utilization of forest products.