MUSCOIDEUM Rose, 1903.
Type : Conzatti & Gonzales 777, Oaxaca, Mexico.
Distribution: Mexico (Oaxaca, Puebla).
Description (by 't Hart & Bleij in IHSP, 2003) :
Stems branched, creeping.
Leaves alternate, obtuse, minute, thickish, closely set along the stem.
Inflorescences terminal with 1 or 2 flowers.
Flowers 5-merous, sessile, sepals ovate, obtuse, ± 1 mm, petals lanceolate, ± 3,5 mm, yellow.
Cytology : 2n = 68
Ray Stephenson (Sedum, Cultivated Stonecrops, 1994, pp 257 - 258) :
Sedum muscoideum is not an uncommon stonecrop in cultivation but it is almost always labelled S. cupressoides Hemsley. The latter is a pink-white-flowered species not in cultivation. The confusion, I think, appears to have started with Rose (1905) who described petals of S. cupressoides as "yellow (but described as rose-colored)." Rose (1903) offered a correct description of S. muscoideum : "[c]losely resembling Sedum cupressoides, but with yellow flowers. Mr. Hemsley has compared the material with his type of the latter species and agrees with me that it is different." Praeger obviously missed the earlier version in the Bulletin of the New York Botanical Garden and depicted S. muscoideum beautifully but with the label S. cupressoides. This error was perpetuated by Fröderström (for petal color of herbaria is often faded), and then Evans. Uhl (1985) pointed out that the true S. cupressoides is similar to S. liebmannianum, and that plants have invariably been confused.
Sedum muscoideum is a distinct plant with tiny, imbricate leaves, tightly appressed to 8-cm (3-in) long, upright stems, and large yellow flowers that are produced in small numbers in summer.