Leaves opposite, margin undulate or revolute.

叶对生，边缘波状或。

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In the non-stomata areas the epidermal cells are oblong and parallel to the long axis of leaves, and the anticlinal walls of epidermal cells are mostly straight or some-times undulate.

非气孔分布区内，表皮细胞长方形，细胞壁直或稍微呈波状，细胞长轴与叶片长轴一致。

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Designers can type in descriptors such as "sharpness" or "acceleration" (which refers to a curve's severity) and watch as the lines of a sports car or tea kettle automatically undulate.

FORBES: Easy Designer