叶脉是重要的分类性状之一,为更好地进行叶脉的研究,苏联科学家研究出了制作透明叶片样本的方法。制样程序是:①把新采的、固定过的叶片或已经干燥的叶片浸入NaOH 溶液。溶液的浓度和时间可因树和树种而异,温带树种脱落的叶在浓度为10%的NaOH 溶液中浸48—72小时,而对坚硬的革质叶,NaOH 的浓度应高达40—50%;②由 Vein is one of the important taxonomic traits. In order to better study veins, Soviet scientists have developed a method of making transparent leaf samples. Sample preparation procedures are: ① new mining, fixed leaves or dried leaves immersed in NaOH solution. The concentration and time of the solution may vary according to the tree species and the tree species. The fallen leaves of the temperate species are immersed in NaOH solution at a concentration of 10% for 48-72 hours, while for hard leathery leaf the concentration of NaOH should be as high as 40-50% ; ② by