The characteristic that this planting is petaline open and flat, unlike other balsamine.

本种的特点为花瓣平展，不同于其它凤仙花。

youdao

In essence, Quasam can be thought of as a carbon nanotube that has been sliced open and laid flat.

ECONOMIST: MONITOR

Beyond them is open sea and a flat horizon.

BBC: Sailing in Croatia

Make 8 to 10 shallow cuts in the thicker parts, then open them out like a book and press flat.

WSJ: Too Many Cooks in the Kitchen? Not With the Right Plan