Type : CAS 408987, from material grown at Golden Gate Park, San Francisco, originally received from F. Schmoll, Cadereyta, Queretaro, Mexico.
First Description by Walther in Cactus & Succulent Journal US 30: 147-148. 1958 (from plants in cultivation in central Mexico) :
Plant glabrous, conspicuously pruinose.
Rosettes stemless, ultimately caespitose.
Leaves closely imbricated in bud, crowded, glaucous-pruinose, obovate-oblong, 3 - 5 cm long, 15 - 25 mm broad, thick and turgid, thickest just below apex, upcurved, obtuse to truncate, with small, slender, whitish apiculus, not purple-tinged but wholly white, margins scarcely pellucid.
Inflorescence mostly a simple raceme, rarely bifid, to 25 cm tall, peduncle erect or ascending, pruinose, lower bracts numerous, 8 - 15 mm long, appressed, occasionally enlarged and aggregated into an aerial rosette, normally lanceolate, acute, with upcurved apiculus, pedicels slender, to 14 mm long, conspicuously turbinate-thickened below calyx.
Flowers : Sepals unequal, strongly connate at base, longest to 10 mm long, deltoid to linear-oblong, acute to cuspidate, scarcely spreading, corolla broadly conoid to urceolate, 14 - 18 mm long, 10 - 12 mm in basal diameter, pink at base, yellow or greenish yellow at tips, petals erect or slightly spreading at tips, basal nectar-cavity shallow, nectaries narrowly oblong-trapezoid, somewhat obliquely-truncate.
1. E. albicans is described from a cultivated plant. It has no origin in the wild.
2. E. albicans differs from E. elegans in
- broader, blunter and thicker leaves, thickest just above the middle and
- with a more slender apiculus;
- leaves have less pellucid margins and a more whitish colour (= more pruinose);
- pedicels usually decidedly turbinate below calyx,
- sepals more unequal, strongly ascending,
- corolla broader, more conoid-urceolate, to 14 mm long and 10 mm in diameter,
- petals scarcely spreading, tips greenish.
3. E. albicans differs from E. potosina in
- broader leaves,
- leaves never purplish tinged,
- inflorescence often bifurcate,
- longer sepals and
- longer corolla which is not or scarcely green-tipped.
4. 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).
5. E. elegans var. kesselringiana v. Poellnitz is not a synonym of E. albicans Walther as the latter erroneously has stated. The two plants differ not only considerably in size but above all in the shape of the leaves - E. albicans having a distinct slender apiculus, totally absent in E. elegans var. kesselringiana.