Xerophyte

Seeds

Black, tuberculate, 1,5 mm in diameter.

Description

Echinocereus rigidissimusSN|8509]]SN|8509]] is a low growing solitary (very rarely few branched) cactus. This species is a great favorite in collections, although it does not last long. Each year’s growth is differentiated by differently coloured band of spines, hence the common name "Rainbow Cactus". Two subspecies are recognized, the nominate form and Echinocereus rigidissimusSN|8509]]SN|8509]] subs. rubispinus (G.Frank & A.B.Lau) N.P.Taylor.

Flowers

Bright pink with much lighter white throat, 6-7 cm long, 6-10 cm in diameter when expanded. Perianth-segments oblong, 3 to 4 cm long, acute. Stamensnumerous, shorter than the style. Stigma lobes approx. 13 green. Areoles on ovary somewhat floccose, very spiny.

Blooming Season

It blooms in late spring summer (May-July).

Spines

No central spines.

Ribs

18-23(-26), low, slightly tuberculate, straight to somewhat undulate.

Stem

Erect, rigid, short cylindric 6 to 20 (-30) cm tall, 4-11 cm wide, usually hidden by the closely set interlocking spines.

Radial Spines

16 to 22 stiff, rigid, pectinate, lying flat on the surface of the plant, straight or slightly curved toward stem, grey, reddish brown, bright pink or pink-and-white, somewhat translucent, arranged in horizontal alternating bands of colour around stem, 5-10 mm long. Mature plants with a good light will generally have red to deep pink spines that band the stems.

Fruits

Globose, greenish or dark purplish brownish very spiny, 3 cm in diameter, pulp white. Fruiting 3 months after flowering.

Areoles

Approximate almost touching or up to 2 cm apart, elliptic, 5 to 6 mm long.