Calcaratum  Baker, 1874

A garden hybrid or unknown origin.

Description (according to Praeger, 1932) :

Rosettes very large, to 15 cm across.

Leaves many, glaucous or rich glaucous-purple, crimson at the base, glabrous, spathulate-oblanceolate, boldly acuminate, slightly tapered below, up to 7 cm long, 2 cm broad, flat on face, convex on back, with regular broad-based rather distant patent cilia.

Offsets strong, on stems up to 6 cm long.

Flowering stem 30 - 40 cm high, pilose, clothed with red deltoid-ovate leaves with longer cilia.

Inflorescence to 20 cm long and 15 cm broad, racemosely branched, lower branches sometimes forked, branches and short pedicels densely pilose.

Flowers : Buds ovoid, blunt, flowers 12- to 16- parted, 2.5 cm across, dull red-purple, calyx 5 mm long, hairy, cut a little more than half-way down into lanceolate acuminate segments, petals pink, with many fine red lines, linear-lanceolate, acuminate, 11 mm long, hairy on back and margin, stamens 6 mm long, filaments crimson, tapering, hairy, anthers red.

Flowerin time : July.

It is the largest-leaved hairy Sempervivum in cultivation, .... It appears to be unknown except in western gardens and is probably a hybrid. The form of the rosette and leaves somewhat suggests that S. wulfenii has played a part in its parentage, but the flowers have no trace of the yellow colour which ought to result from such a cross .... that S. tectorum had a part in its production is an obvious suggestion.