Definition: A depression caused by erosion by water or ice. Low-lying land bordered by higher ground; especially elongate, relatively large gently sloping depressions of the Earth's surface, commonly situated between two mountains or between ranges of hills or mountains, and often containing a stream with an outlet.
Definition: Non-woody plants growing attached to external support without contact to the ground. Non-woody hemiepiphytes either germinate on other plants and then establish roots in the ground, or germinate on the ground and later disconnect from the soil
Definition: Non-woody plants growing attached to external support without contact to the ground. Non-woody hemiepiphytes either germinate on other plants and then establish roots in the ground, or germinate on the ground and later disconnect from the soil