Xerophyte

Central Spines

1 - 4, the uppermost the longest, needle like, straight or slightly curving, with thicker base, glassy brown with black tip, to 50 mm long.

Seeds

Brown, flattened keeled, 1,2 mm long and 0,8 mm wide. Hilum subbasal.

Description

Mammillaria erythra is a solitary, flattened globose, cactus, with long pyramidal, four-angled tubercles and short distinctive spines. It is at most a race of the variably spined Mammillaria mystaxSN|20654]]SN|20654]]. The key difference by which the two were separated, namely the reduced spination, the dull-green epidermis, the solitary growth and the body size, seems entirely spurious. The name Mammillaria erythraSN|20663]]SN|20663]] is not accepted by many botanists that treat it as synonym, but it still has a value for a collector because they identify plants with particular characters.

Roots

Fibrous.

Note

Mammillaria erythraSN|20663]]SN|20663]] is considered by Werner Reppenhagen a connection between Mammillaria mystaxSN|20654]]SN|20654]] and Mammillaria sartori.

Tubercles

Pyramidal, firm, 4-angled, keeled, 15-18 mm long and 12-15 mm wide. Axil with short white wool and 3-10 short, glassy white with reddish brown tip, straight bristles.

Flowers

Carmine, funnelform, 18 - 22 mm long and 10 - 12 mm in diameter, not flowering frequently.

Stem

Solitary, flattened globose, sunken apex, 4-9 mm high and 7-30 cm in diameter, dull green, in habitat reddish. With latex.

Radial Spines

None to 8, needle like, straight, smooth, whitish to brown, 2-6 mm long.

Fruits

Dark carmine, club-shaped, 10 - 15 mm long and 3 - 5 mm wide, ripens 5 months after flowering.