Plants belonging to the bitterroot genus, or Lewisia, are perennial herbs, generally growing from a short, thick, more or less branched taproot, which is topped by a short, sometimes very thick root crown at or below ground level, sometimes from a spheric thickened root. The above-ground parts of the stem are restricted to the flower cluster. Leaves generally grow in a basal rosette. The leaves are simple, entire or not, usually with a wide base and an edge which is generally more or less translucent. The flower cluster grows from one to many naked flower stems. They are generally leafless but bracted, sometimes disjointing in age, and are 1– to many-flowered. The flowers have 2-8 sepals 2–8, which are free and persistent. There are 4-18 petals, which are variously colored, and overlapping in bud. The flowers have 5 to many stamens. There are 2-8 styles, which are fused at base. The 2-8 stigmas are thread-like. The fruit consists of a capsule, which is translucent, spheric or ovoid, opening by a lid-like top near base. The 2 to many seeds are dark, generally shiny, smooth or finely covered with warty bumps The Genus has about 20 species worldwide, endemic to western North America.
Guide to Identify Presented Species of Genus Lewisia
FLOWERS PINK TO PURPLE
L. pygmaea – Pygmy Bitterroot Low herb, 1-3 cm tall. Dry, exposed sites, often gravelly, montane to alpine.
Flowers white to pink-purple, 15-20 mm wide, with 5-9 petals and 2 sepals.
Leaves basal, 5-15 cm long, succulent, flat and linear to narrowly spoon-shaped.
L. rediviva – Bitterroot Low herb, 1-3 cm tall. Dry, exposed sites, often gravelly, plains to montane.
Flowers pink, 4-6 cm wide, with about 15 petals and 6-9 pinkish sepals.
Leaves basal, 1.5-5 cm long, fleshy, linear- to club-shaped and nearly cylindrical.
