Miner's-lettuce is a native winter or spring annual. Miner's-lettuce has two stem leaves that fuse to form a disc just below the flower stalk. The elongate stalk bears numerous small flowers.
Fruits are tiny, three-valved capsules containing one to three seeds.
Selfing is the most common method of pollination, but insect pollination also occurs. Seeds are dispersed by explosive dehiscence. He also found it on burned sites. Some polyploids occur on specialized, distinctive sites. The Columbia River Gorge octoploid, for example, occurs only on north-facing basalt talus slopes or cliff faces.