PlantFiles: Stemless Evening Primrose
Oenothera triloba

Hardy in zone 3; fascinating to watch the flowers open at dusk. Seeds are embedded at ground level in the base of the plant, as the flower stems are actually extremely elongated styles.

I love this plant. As children, my siblings and I used to wait and watch the flowers open every summer. I was thrilled to find it again as an adult--it is not sold in stores. Plant it where you sit in the evenings so you can watch the flowers open. They last only one night. Don 't deadhead so they reseed. They don't transplant well because they have a long taproot like a dandelion. Actually the leaves look almost identical to a dandelion so you have to be careful you don't mistake it for a dandelion and weed it. I grow transplants in peat pots so you can plant the whole thing without disturbing the taproot.

Stemless Evening Primrose (Oenothera triloba) is a native plant and is a threatened species in Kentucky. It has become extinct in Indiana. In Texas, Stemless Evening Primrose can be found in clay or dry limestone soils of the Blackland Praire, Rolling Plains and Edwards Plateau Regions in dry open areas with drained soil such as barrens, prairies, floodplains, slopes, hillsides, rock outcrops in fields and grassy areas. It is a frequent lawn invader. The plant forms a rosette shape like a dandelion with broadly lobed leaves low to the ground. Because it is very low growing (usually 8 inches tall or less), it withstands mowing very well. The up to 4.5cm (1.75 ") wide flowers are bright yellow when they open about half an hour before sunset. When they close about noon the following day, their color has faded to a pale yellow. If you observe them opening, you will be surprised. They go from buds that resemble little okra pods to flowers in about a minute. This is so fast that you actually can see them move. The seedpods form at the base of the flower stem and are hidden in the foliage at ground level. They resemble tiny pinecones. Deer resistant is high. This hardy perennial is a good plant for rock gardens.