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..
Fleshy mostly glabrous herbs, erect or decumbent, mainly with alternate, often imbricated, entire or dentate leaves, and perfect flowers in terminal often 1-sided cymes. Calyx 4-5-lobed. Petals 4-5, distinct. Stamens 8-10, perigynous, the alternate ones usually attached to the petals. Filaments filiform or subulate. Scales of the receptacle entire or emarginate. Carpels 4-5, distinct, or united at the base, spreading; styles usually short; ovules . Follicles many-seeeded or few-seeded. [Latin, to sit, from the lowly habit of these plants.]
About 200 species, mostly natives of temperate and cold regions of the northern hemisphere, but many in the mountains of Mexico and a few in the Andes of South America. Besides the following, about 15 others occur in the western parts of North America. Type species: Sedum Telephium L.
Cyme regular, compound, the flowers not secund; leaves broad, flat.
Petals purple; plant somewhat glaucous; petals twice as long as sepals.
Petals pink; plant very glaucous; petals 3-4 times as long as the sepals.
Flowers secund along the branches of the cyme.
Leaves short, thick, ovate, densely imbricated.
Leaves linear or terete, scattered on the stems.
Annual; petals little longer than the sepals.
Perennial; petals twice as long as the sepals.
Plant 3'-6' high; native, western.
Plant 8'-12' high; introduced in a few places.
Petals purple or white.
Leaves terete; petals purple, pink, or white.
Leaves flat, spatulate or obovate; petals white.
Lower leaves verticillate in 3's.
Leaves all alternate.