Silphium laciniatum

Compass plant ( Silphium laciniatum )

The compass plant ( Silphium laciniatum ) is a flowering plant in the sunflower family ( Asteraceae).

Physiological adaptation

The plant grows in the prairies of the United States. You can set as an adaptation to strong sunlight their vertically aligned sheets in north-south direction. The leaf tips show then generally north-south direction, the leaf blades have, however, to the east or west. Experiments have shown that the rate of photosynthesis and CO2 assimilation in the horizontal position of the leaves is indeed exactly the same as in the vertically pointing in a north-south direction leaves, but that the water consumption in the midday sun is much larger. In position of leaves in an east-west direction, the CO2 assimilation would be less.

This sheet alignment Silphium laciniatum one of the representatives of the compass plant. The English names are prairie compass plant compass or flower.