TITLE:
Comparative Morphology of the Leaf Epidermis in Ligusticum (Apiaceae) from China
AUTHORS:
Jing Zhou, Zhenwen Liu
KEYWORDS:
Leaf Epidermis, Ligusticum, Taxonomy, Umbelliferae (Apiaceae)
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.6,
May
17,
2018
ABSTRACT: To investigate the taxonomic value of leaf epidermal characters in developing a classification for Ligusticum (Apiaceae), thirty-eight species (including a cultivar) of the genus were examined using both light and scanning electron microscopy. Our results show that the infrageneric classification of Ligusticum based on the characters of involucel bracteoles, mericarps, and pollen grains was not supported as few epidermal characters were relatively constant at section level. Evidence from leaf epidermis, similar to that from molecular and morphological data, supports the separation of Tilingia (i.e. L. ajanense and L. tachiroei) from Ligusticum. Ligusticopsis was found to be indistinguishable from Ligusticum in epidermal characters. Furthermore, results from epidermal analysis, together with that from cytological evidence, fruit morphology as well as molecular phylogenetics suggest that L. delavayi should be transferred out of Ligusticum.