Echeveria potosina
Type : Romeo & Posselt s.n. CAS 223896. (Walther 1933/25) Plant originally from cultivation in San Luis Potosí.
Etymology : Referring to the city of San Luis Potosí whence it was sent.
First Description by Walther in Cactus and Succulent Journal US 7: 61. 1935 :
Plants stemless.
Rosettes dense, with few or no offsets.
Leaves very thick and turgid, obovate-cuneate, mucronate, 4 - 6 cm long, 2 - 3 cm broad near apex, of marble-like texture, colour pale glaucous-green, with decided purplish tinge at tips.
Inflorescence a secund raceme to 30 cm tall, bracts few, appressed, pedicels 6 - 7 mm long, thickened below calyx.
Flowers 6 - 7, sepals very unequal, three very short, the two longer ones at most 3 mm long, scarcely extending beyond base of corolla; corolla strongly urceolate, to 13 mm long, 9 mm in diameter at base, 7 mm at apex of the outcurved tips of segments, begonia-rose, tips greenish, segments thinnish, scarcely keeled, little hollowed at base, connate for 4 - 6 mm, carpels thick, styles short, greenish, nectaries thin, oblique, yellow, to 2 mm wide.
Flowering time from March to June.
Cytology : n = ca 112 (according to C.H.Uhl, Haseltonia 4, 1996).
1. E. potosina differs from E. elegans by
- leaves thickest below apex,
- leaves frequently purplish tinged,
- broader, obovate, scarcely spreading bracts,
- turbinate pedicels and
- short, deltoid sepals (not exceeding the base of the corolla) and
- broader corolla.
2. E. potosina differs from E. albicans by
- longer and narrower leaves,
- leaves usually purplish tinged,
- inflorescence never bifurcate and
- corolla urceolate, 12 - 13 mm long, 9 mm in diameter.
3. Uhl comments : " These three species [E. elegans, E. potosina and E. albicans] seem not very distinct from each other and probably [...] are better considered variations of the same species" (Haseltonia 4, 1996).
4. The description of E. potosina has been made from a plant of unknown origin, and it has never been found in the wild. In spite of the fact that this name is now only a synonym of E. elegans and therefore obsolete, it can still be found on actual plant lists, used for several different plants with or without known origian and in contradiction to the protologue it is mostly - wrongly - applied to strongly offsetting plants.