Prairie Evening Primrose

From LoveToKnow Garden

Prairie Evening Primrose (Ce. Missouriensis) - A precious herbaceous plant from N. America, with prostrate downy stems and clear yellow flowers, sometimes 5 inches in diameter, and borne freely. There is no more valuable border flower, and when well placed in the rock garden it is effective, especially if the luxuriant shoots are allowed to hang down. I plant it as an undergrowth to a tea-rose. As a border plant it does not grow so freely in cold clayey soils as in warm soils. The blooms open best in the evening.