Xerophyte

Central Spines

1 to 4 (rarely absent), curved upward, 15-25(-45) mm long.

Seeds

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

Description

Melocactus zehntneriSN|20575]]SN|20575]] is one of the more common Melocactus from Brazil. It shows great variation and is sometimes difficult to separate one local form from another. Many of this forms have received unnecessary names. The great variationin almost all characters of Melocactus zehntneriSN|20575]]SN|20575]] has led to confusions in taxonomy.

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 more or less exerted at the top of the cephalium.

Chromosome Number

2n = 44

Spines

Very variable in size colour and form,rather stout, yellow, brown, or reddish, overlaid with gray except at the dark tips, sometime hooked in seedlings.

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.

Fruits

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

Habit

Usually stay solitary, mature plants are easily recognizable by their cephalium, 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.

Radial Spines

7-11, weakly to strongly curved backward, 19-30(-45) mm long, lower oneslongest.

Areoles

1,2-2 cm apart.