托叶铁科(苏铁目)羽片脉序和羽片解剖学研究

Venation and Anatomy of Pinnae in Stanger iacea(Cycadales)

摘要:

详细研究了托叶铁科两属的2种代表植物Stangeriaeriopus和Boweniaserrulata的羽片脉序和羽片解剖学。两个属在气孔器特征与不具副传输组织方面极为相似,而在气孔的分布、羽片脉序式样与叶缘形态、粘液道的有无、海绵组织与栅栏组织的分化、工字厚壁组织与表皮细胞垂周壁特征方面则有较大的差异。将这些特征与苏铁科和泽米铁科作了比较,并讨论了这些特征在系统学上的意义。研究结果支持Stevenson(1992)将该科分为两亚科以及托叶铁科是介于苏铁科与泽米铁科之间的观点。

Abstract:

Pinna venation pattern and pinna anatomy of two species, S tangeria eriopus and Bowenia serrulata, represent atives of the two genera in Stangeriaceae were studied in this paper. The two sp ecies (genera) are similar in stomatal character and in the absence of accessory transfusion tissue, but they are very different in stomatal distribution, pinna venation pattern and pinna marginal shape, presence or absence of mucilage cana l, differentiation of palisade and spongy parenchyma, characteristics of girder parenchyma and epidermal anticlinal wal1． Pinna venation and pinna anatomy of Stangeriaceae are compared with those of Cycadaceae and Zamiaceae． Stevenson's classification (1992) with two subfamilies and the treatment of Stangeriaceae as a transitional evolutionary position between Cycadaceae and Zamiaceae is supposed by present study．