Xerophyte

Habit

Usually stay solitary, mature plants are easily recognizable by their cephalia, that have a covering of wool and orange or red bristles, The immature plant looks like a smallish barrel cactus, and there is nothing in its appearance that would suggest a melocactus.

Central Spines

Usually 1 curved upward.

Seeds

1,2-1,3 x 1-1,1 mm noticeably tuberculate at end opposite hilum.

Description

Melocactus zehntneriSN|20575]]SN|20575]] subs. canescens is one of the local form of the very variable Melocactus zehntneriSN|20575]]SN|20575]] distingusced from the standard species for it somewhat short cylindrical, often globular, stems with about 15 ribs. There are about seven stout brownish-gray radial spines, one central and the cephalia are densely covered by orange red bristle.

Cephalium

6-11 cm or more long, 6-10 cm in diameter, with dense, fine, pale pinkish red bristles and sparse or abundant white to creamy white wool.

Flowers

Small inconspicuous (15-25 mm long, 4-13 mm across) pale to deep or purple, self pollinating, growing even with or well exserted at the top of the cephalium.

Spines

Rather stout, yellow, brown, or reddish, overlaid with grey except at the dark tips.

Ribs

10-16 (rarely to 19) sharply acute.

Stem

Strongly longitudinally ribbed depressed-globose or spheroid to cylindrical, pale to dull green, often glaucous, 10-50 cm high, 9-25 cm in diameter.

Radial Spines

mostly 7, weakly to strongly curved backward, lower ones longest.

Fruits

Clavate, white or pale to deep lilac-pink, 12-20 mm long 4-8 mm in diameter.

Areoles

1,2-2 cm apart.