木兰科叶结构的比较解剖及其系统学意义

对国产６属１１种木兰科植物叶片的结构进行了比较解剖研究。通过比较叶的表皮、皮皮、叶肉及中脉等解剖特征，结果表明：（１）上、下表皮细胞的形态结构在种之间存在差异，（２）下皮存在于木莲属、木兰属、含笑属、合果木属的部分种中，连续或不连续：（３）叶肉中栅栏组织和海绵组织的分化程度以及细胞形态在种间存在差异：（４）中脉维组织具原始怀，维管束环状排列，具髓，外有厚壁细胞组成的维管束鞘包围；维管束的数目在属间

COMPARATIVE ANATOMY OF LEAVES IN MAGNOLIACEAE AND ITS SYSTEMATIC SIGNIFICANCE

The comparative anatomical structure of leaves of 11 species in 6 genera in the Magnoliaceae of China was studied. By the comparison of the anatomical features of epidermis, subepidermis, mesophyll and midrib, the result shows: (1) The shapes and structures of the upper and lower epidermis from leaves of 11 species are different. (2) Some members of Manglietia, Magnolia, Michelia and Paramichelia have a subepidermal layer beneath the upper epidermis entirely or not entirely. Other members lack specialized subepidermal layer. (3) The differentiation and cell shapes of the palisade parenchyma and spongy parenchyma from the leaves of 11 species are different. (4)Midrib vascular tissue is primitive with vascular bundles arranged concentridally and medulla by the encirclement of the vascular bundle sheath. Vascular bundle sheath is composed of sclerenchyma cells. The number of vascular bundles is different in 6 genera 11 species.The anatomic features of leaves in the Magnoliaceae provide new experimental evidence for systematic evolution and classification.