Flower:

Loose clusters at the tip of the stem and arising from some leaf axils, in racemes of 3 to 10 flowers. Flowers are ¼ to 1/3 inch across with 5 white to pinkish petals, 5 pink to purple-tipped stamens and a 3-parted style. Cupping the flower are a pair of green, egg-shaped sepals shorter than the petals. Flower stalks are slender, hairless, up to about 1 inch long.

Leaves and stems:

Leaves are opposite, ¾ to 2 inches long, up to ¾ inch wide, hairless, toothless, elliptic to spatula-shaped, rounded to bluntly pointed at the tip, tapering at the base to a short stalk. Stems are slender, erect to sprawling, hairless and light green.

Colonies are formed from both rhizomes (underground stems) and stolons (horizontal, above ground stems). Bulblets are usually formed at the tip of these stems, which take root and send up new shoots.

Fruit:

Fruit is a 3-sectioned capsule containing 1 to 3 tiny black seeds.

Notes:

This is one of the rarest species in Minnesota, and disjunct from the larger populations in the western US, where it is found in mountain meadows, stream and river banks, and wetands. According to the DNR, it was first discovered in the Mississippi River Valley in Winona County in 1889 and is believed to be a glacial relic that was stranded in the driftless area following the retreat of the last glacier. The single known remaining population is on private land, semi-protected on the embankment of a small stream where it has persisted perhaps for thousands of years, lying in a thin layer of mud over sandstone. Due to its rarity, it was listed as an Endangered species in 1984.

It is said to flower from early June through mid-July, but we visited the site multiple times during what should have been peak season and never saw a bud, let alone a bloom. Since it spreads vegetatively it may not require many blooms, so why waste the energy? While it's related to Spring Beauty, the small white flowers might be mistaken for one of the Sandworts, and when flowers are not present it might be mistaken for a Chickweed, but these all have stalkless leaves that are more lance-elliptic or linear and many are hairy, where Montia has stalked, more spatula-shaped leaves and is hairless overall.