This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Fibrous-rooted succulent herbs, mostly annual in duration, with basal petioled leaves, and a pair of sessile or connate-perfoliate leaves on the stem below the inflorescence. Flowers pink or white, racemose. Calyx of 2 persistent sepals. Petals 5, distinct and equal. Stamens 5. Ovary 2-3-ovuled. Capsule 3-valved, 2-3-seeded [Greek, referring to the marsh habitat of some species.]
Twelve species, or more, natives of western North America. Type species: Limnia sibirica (L.) Haw.
Claytonia perfoliata Donn; Willd. Sp. Pl. 1: 1186.
1798. L. perfoliata Haw. Syn. Pl. Succ. 12. 1812. Montia perfoliata Howell, Erythea 1: 38. 1893.
Annual, roots fibrous, stems several, erect or ascending, simple, 3'-12' high, bearing a pair of connate-perfoliate leaves near the summit, completely or partially united into an orbicular concave disk, 2' broad or less. Basal leaves rhomboid-ovate, long-petioled, the blade 1' long or more, obtuse or acute at apex, narrowed into the petiole; petioles shorter than the stems; raceme usually pe-duncled, loosely or compactly several-flowered, sometimes compound; bracts broad, deciduous; flowers white or pink, 3"-5" broad; petals and stamens 5; capsule globose, 1"-2" in diameter, 2-5-seeded.
Established near Painesville, Ohio. Native from British Columbia to Mexico. April-May.