【摘要】 从国产１７７科阔叶树（隶４５科１３２属）木材构造的电镜观察中筛选出５１种（隶２０科４４属）木材的导管、维管管胞内壁上具有螺纹加厚，对所观察到的螺纹加厚进行了比较，在国外学者将螺纹加厚分为三种类型的基础上，近一步分为四种类型：１．分枝型；２．不分枝型；３．涡流型；４．附物型。其中分枝型和不分枝型又分为Ⅰ型和Ⅱ型。同时对螺纹加厚的形成和分布进行了讨论。更多还原

【Abstract】 Spiral thickenings in the yessels elements of 51 species belonging to 44 genera and 20 families chinese hardwoods were investigated by SEM and TEM.They were found in the vascular or vasicentric.Four types or spiral thickening were proposed,namely,brached,nonbrached,swirled and vestured;their forms,functions,distributions and origins were described in detail.Occurrence or non-occurrence and distribution of the spiral thickenings must be considered as a useful identification of hardwood.更多还原