| Abstract: | The leaf structure and morphology, the structure and location of oil cells in leaves of 82
species and 1 subspecies in 10 genera of the Magnoliaceae were comparatively studied using tissue
clearing, paraffin sectioning and thin sectioning. In leaves of Liriodendroideae, some of abaxial epidermal cells are papillose and the vascular tissue of the main vein appeared to be separated. However, papillose cells were not found and there were uniseriate, multicellular or unicellular hairs distributed on the epiderm, and the vascular tissue of the main vein appeared to be continuous in leaves
of the Magnolioideae. Furthermore, in the Magnolioideae, the structure of leaves of Manglietia were
different from that of Magnolia. These results support the separation of Magnolioideae and Liriodendroideae, and suggest that Manglietia and Magnolia be independent genera, which is consistent
with Law’ s taxonomic scheme. Oil cells are one of marked features of the leaf anatomy of the Magnoliaceae, and they are mainly distributed in the palisade tissue in leaves of 47 species and in the
spongy tissue in leaves of 5 species, and dispersed in the whole mesophyll in leaves of 31 species.
The size and location of oil cells in leaves, combined with the thickness of leaves, the number of
layers of the palisade tissue, the ratio of palisade tissue to spongy tissue in thickness, the hypo-derm, and the type of hairs may be used as the characteristics of genera and even species. |
