叶柄

Leaf base often narrowed into a petiole, spurless.

叶基部通常缩小成叶柄，无距。

Trema polygama, described from Yunnan, differs in having the inflorescences shorter than the adjacent petioles.

发表自云南，不同在于花序短于临近的叶柄。

The development of xylem is of mesarch.Stomata are monocyclic type.

叶脉、叶柄、上胚轴的维管外韧型。

Leaves alternate, shortly petiolate, leathery, margin entire, venation pinnate or palmately triplinerved.

叶互，具叶柄短，革，全，羽状脉或者掌状离基三出脉的。

Characteristics: Terrestrial ferns; stipes tuft, backlish at base; young fronds pinnaye with wider pinnae, when getting older, the fronds become bipinnate or tripinnatifid with slender pinnules.

地，叶柄丛，基部黑色；较年轻的叶子一回羽状复叶，较老的叶子二回或三回羽状复叶。