x amecamecanum Praeger, 1917
Parentage : Sedum praealtum ssp. monticola x S. goldmanii (as Villadia batesii)
Synonym : xSedadia amecamecana (Praeger pro sp.) Moran (1975)
Distribution : Originally collected on the Trans-Mexican Volcanic Belt by C.A.Purpus on Mount Iztaccihuatl towards Amecameca in January 1906.
Growing on 2500 - 4000 m as a true alpine it is almost hardy and dislikes hot greenhouse conditions.
Description (according to t' Hart & Bleij in IHSP, 2003) :
Glabrous perennial subshrubs with many widely spreading branches and shorter sterile branches, 20 - 30 cm tall.
Leaves alternate, oblanceolate, subacute, reflexed, slightly spurred, flat, 15 - 20 x ± 6 mm, light green.
Flowering branches erect to ascending.
Inflorescences densely cymose to corymbose, bracts sepal-like.
Flowers 5-merous, sepals basally free, shortly spurred, unequal, broadly linear, obtuse, 4 - 6 mm, green, petals basally slightly connate, oblong, subobtuse, shortly mucronate, 8 - 9 mm palse yellow, filaments and anthers yellow.
The hybrid is intermediate between the parents and according to Clausen sterile or nearly so. Uhl has noted terminal as well as axillary inflorescences. A fairly similar hybrid has been found on 3000 m on Popocatepetl. As only S. praealtum ssp. parvifolium is growing on Popocatepetl the latter might result from S. goldmanii crossed with S. praealtum ssp. parvifolium.