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Systematic implications of pinna venation and pinna anatomy in Zamiaceae

泽米科植物羽片脉序和解剖学及其系统学意义

作者：TANG Yuan-Jiang, LIU Nian, LIAO Jing-Ping, XIE Zhong-Yu

期刊：植物分类学报 2004年 4期

关键词：羽片脉序；羽片解剖学；泽米科；

Keywords:pinna venation, pinna anatomy, Zamiaceae,

Abstract:Pinna venation and pinna anatomy were examined in ten species of six genera of Zamiaceae (Cycadales), which represent all four tribes. Pinna venation consists of dichotomous parallel veins without a midrib. The vein endings connect to each other in different forms in Dioon spinulosum, Encephalartos friderici-guilielmii and Macrozamia moorei, while they are never connected and reach the pinna margin in Lepidozamia peroffskyana, Ceratozamia mexicana var. robusta, C. hildae, Zamia muricata, Z. debilis, Z. furfuracea and Z. floridana, and gradually fade out in L. peroffskyana, C. mexicana var. robusta, and C. hildae. In transverse section, pinna generally consists of an adaxial epidermis and an abaxial epidermis, hypodermal sclerenchyma and mesophyll which may be differentiated into distinct adaxial and abaxial palisade regions, or adaxial palisade only, or entirely spongy tissue. However, typical spongy parenchyma and transfusion tissue are absent from this family. Mucilage canals are opposite the vascular bundles in D. spinulosum, or alternate with vascular bundles in E. friderici-guilielmii, L. peroffskyana and M. moorei. Girder sclerenchyma is connected with the abaxial epidermis only in C. mexicana var. robusta and C. hildae, but with both adaxial and abaxial epidermis in Z. muricata, Z. debilis, Z. furfuracea and Z. floridana. Pinna venation and anatomy support Stevenson‘s classification of Zamiaceae into two subfamilies.