The leaf surface is mostly smooth and no waxy or corneous types; however there are some species with the surface covered with ridges of wax or waxy types.
叶表面通常光滑无蜡质或角质，部分种叶表面具薄片状或层状蜡质。
2
Still can lose furrow area flexibility and corneous layer to add thick cortex to depart additionally, this also can drive circumjacent skin to undertake updating.