Stemless Evening Primrose (ee-no-THEE-ruh: try-LO-buh) Onagraceae:
A Low growing species with dandelion-like foliage and larger yellow flowers. Plants grow lees than 6 inches tall and the flowers open late in the day, near sunset. The flowers open very rapidly and many like to use the plants near a bench were they can sit in the evening and see the flowers open. The seeds are dispersed by rain which hits the specifically shaped seed capsules, which are sometimes termed 'splash cups', rain is an uncommon seed dispersal mechanism called Ombrohydrochory.
The seeds of Oenothera triloba germinate in a few days at 70F. Surface sow and keep moist but not wet, as wet soil mediums can cause root rot.