Miner's lettuce is an annual with several to many stems either lax or ascending from 3-35 cm high. The basal leaves are linear-spatulate to long-petiolate with oblanceolate to rhombic-obovate blades up to 3 cm wide and roughly the same length as the flower stems. The two stem leaves are found at the distal end of the stem, where they adjoin together to form a disk through which the stem passes (hence the species name perfoliata, meaning the stem passing through the leaf). This is a key diagnostic characteristics for this species. This disc range from 0.6-5 cm wide.
The inflorescence is a short raceme found directly above the disc. Individual flowers are white or pink with 5 short petals, 2 green petals, and 5 stamens.
Current classification has changed the genus name from Montia to Claytonia.
Miner's lettuce is found in seasonally moist places in open to shady woods in the bottom lands to the lower mountains.
Miner's lettuce is found from British Columbia south along both sides of the Cascade Mts. to Baja California and east to Arizona, Utah, Wyoming and the Dakotas.