BORISSOVAE Wale, 1942
Synonym : Sempervivum caucasicum var. borissovae (Wale) Gurgenidze (1972)
Section Sempervivum
Distribution : Caucasus; between rocks on a ridge, ± 1850 m, known from the type only.
Description (according to 't Hart, Bleij & Zonneveld in IHSP, 2003) :
Rosettes rather open, flat, to 3 cm in diameter.
Stolons short and slender.
Leaves obovate, strongly mucronate, glabrous, subterete, green, reddish-brown in the upper half, ± 22 x 9 mm, ± 3 mm thick.
Flowering branches 7 - 10 cm, cauline leaves glabrous except for the dorsal base, green or reddish-brown.
Flowers 12-to 14- merous, ± 2.5 cm in diameter, sepals reddish, to 8 mm, petals lanceolate, deep rose, with somewhat lighter, slightly irregularly serrated margins, filaments lilac to dark red, anthers red, styles pale pink.
Cytology : 2n = 72
Closely allied to S. caucasicum, but with smaller rosettes and flowering branches. Gurgenidze (1972: 29) treated S. borissovae as a subspecies of S. caucasicum.