Xerophyte

Central Spines

1-4(-6), straight. Lowermost one (in adult plants only) with a tuberous thickened base, porrect or pointing downward, 20-25 mm long, other 3(-5) central spines, thinner, spreding, pointing upward. The colour of the central spines is similar to that of the radials, or the centrals, particularly the lower central, may be blue-grey (rarely dark reddish-purple) for more that half of their length.Juveniles of Echinomastus warnockiiSN|31306]]SN|32469]] have circular areoles in which there is a central region ca. 1 mm across that is devoid of spines, and 11-15(-17) radial spines with blue-grey tips, and often one or two central spines with violet tips. In seedlings that are less than 1 cm long, at least some of the radial spines are pubescent.

Seeds

Flattened obovate, to subglobular, 1.5 mm long, 2 mm wide and 1 mm thick, black, minutely papillate.

Description

Echinocactus warnockiiSN|32472]] is a solitary blue-green cactus densely covered, but not completerly hidden, by spines. Plants are variable in length and thickness of spines, yet in their colour. Nursery catalogues sometime distinguish two colour variants

Roots

Fibrous and diffuse.

Flowers

Near apical, about 23-30 mm long and broad, widely opening white to creamy white, rarely pinkish, self-incompatible. Lower perianth-segments with a distinctive broad green stripe and white or pink membranous margin; uppermost segments lanceolate, 9-12 mm long, about 4.5 mm wide, apex pointed, margin wavy, pink to white. Filaments whitish, pale green, or pale yellow, 3 mm long; anthers dark yellow, oblong, 0.7 mm long; pistil light green, about 10 mm long; stigmatic lobes 5-10, about 1 mm long, light green, erect.

Blooming Season

Flowering usually in late winter to early spring (Feb—Mar). Plants produces 1-2 flowers at the same time, opening in early afternoon on warm sunny days, closing at night and reopening again for 2-4 days. Flower production may go on for several weeks.

Spines

Dense, almost covering the body.

Stem

Single, light coloured, blue-green, ovate to elongated, 7-11(-20) cm tall, 5-7.5(-10) cm thick, with 13-21 ribs, rarely more, well-defined, laterally compressed and forming distinct tubercles. Tubercles about 10 mm long, 6 mm wide.

Radial Spines

12-14-(17), acicular, slightly smaller than the upper 3centrals, but otherwise like the centrals, irregularly radially arranged from the centre or resembling radials, divergent, stiff, and overlapping, although some of the radial spines may be some-what appressed. Upper half of which slightly longer (about 25 mm), lowermost ones 8-20 mm. All the young spines bright red with dark brown tips, later coloured in various shades of tan, dull yellow or brown, grey at the base and "chalky-blue" or blue-grey (rarely reddish-purple) on the distal portion.

Fruits

Green, becoming brown when ripe, spherical c. 6-10 mm in broad, with few white, very wide scales, retaining the shrivelled floral remnants until full maturity.

Areoles

Elliptic, 3 mm wide, about 10 mm apart.