Sedum ser. Alba, A. Berger, 1915

Mifsud, Stephen, Stephenson, Ray & Thiede, Joachim, 2015, Sedum album subsp. rupi-melitense (Crassulaceae), a new vegetatively reproducing subspecies from Malta (Maltese Islands, Central Mediterranean), Phytotaxa 227 (2), pp. 135-146 : 142

Key to the taxa of Sedum ser. Alba :

1 Leaves glabrous or sparingly papillate ( Sedum album ).....................................................................................................................2

- Leaves densely papillate ( Sedum gypsicola ).....................................................................................................................................3

2 Peduncular leaves and floral bracts on the inflorescences present; nectary scales present; stamens 10, each with a functional, dark violet or dark red anther; fruits and seeds developed, fertile; reproducing by seeds and vegetatively ................................................ .................................................................................................................................................................. Sedum album subsp. album

- Peduncular leaves and floral bracts on the inflorescences absent or vestigial; nectary scales absent; stamens 10, but (3–)5 with abortive anthers; anthers dark maroon to blackish-brown, mostly indehiscent; fruits and seeds undeveloped, sterile; reproducing vegetatively (flowering extremely rare) ...................................................................................... Sedum album subsp. rupi-melitense

3 Leaves spreading or imbricate-appressed; anthers dark violet to dark red; style ca. 1 mm long......................................................... ....................................................................................................................................................... Sedum gypsicola subsp. gypsicola

- Leaves densely grouped cone-like, but not imbricate, cylindrical; anthers dark red; style 1–1.5 mm long ........................................ ....................................................................................................................................................... Sedum gypsicola subsp. trinacriae