A course weedy plant which grows on rocky hillsides and in disturbed
areas.
There are barbed hairs on the leaves, which may stick to clothing
and to animal fur.
Each plant usually has many spectacular large yellow flowers
growing on branching stems. They bloom in
the evening and close the next day when the sun gets high.
Each flower is 3 or 4 inches across, with five yellow petals
and hundreds of stamens.