Xerophyte

Central Spines

1-4 brown needle-like ascending, dark brown or black, the lowest one elongated (up to 1.5 cm. long), hooked at apex or sometimes straight;

Seeds

1 mm in diameter, constricted below, black with a large elliptic basal hilum.

Description

Mammillaria swingleiSN|8816]]SN|8817]] is a basally branching cactus that forms tight clumps. It is now often considered a synonym of Mammillaria sheldoniiSN|8817]]SN|8816]] to which it don’t shows significant differences.

Tubercles

Cylindrical four-sided basally, keeled 7-10 mm long , 5-7 mm in diameter; axils without wool, but sometimes with a few more or less setose bristles. Tubercule arrangement

Flowers

Wide funnel-form purplish pink (White and yellow varieties are mentioned) inodorous 3 cm in diameter. Outer perianth-segments greenish or sometimes pinkish; margins somewhat scarious; inner perianth-segments narrowly oblong, nearly white with a brown stripe down center; style pink, twice as long as the pink filaments; stigma-lobes 8, linear, pointed, green.

Blooming Season

April, In cultivation the flowers remain open for several days (at least three).

Radial Spines

11-18 obscuring the tubercles, 7-14 mm long, needle-like rather stout, spreading, dull white with dark tips.

Fruits

Pale scarlet, clavate, 14-18 mm long.