Chalazal region morphology on the endotesta of Magnoliaceous seeds and its systematic significance
木兰科种子内种皮合点区形态及其系统学意义

The chalazal region on the endotesta of 52 species from ten genera in the Magnoliaceae was observed under scanning electron microscopy, and is found to be of two types in morphology: the pore type and the tube type. The former is characterized by having a simple pore, and was observed in Manglietia, Aromdendron, Talauma (eight species), Elmerrillia, and Liriodendron. The later is characterized by having a more complex structure consisting of a central hollow tube contained within a hole. This type was observed in Manglietiastrum, Talauma (three species), Alcimandra, Michelia, Paramichelia, and Tsoongiodendron. Transitional types between these two types were observed in some species of Magnolia. Such chalazal morphology is stable within genera and has been found only in the Magnoliaceae. It is noteworthy that the pore type is mainly found in the relatively primitive groups, while the tube type mainly in the relatively advanced ones of the Magnoliaceae.