Etymology: The species name zephyranthoides comes
from the Greek suffix “oides”, resembling, similar
to; and for the genus Zephyranthes (fam.
Armarillidaceae). For the similar looking large flowers.
Stems: Flattened-globose, apex depressed, 1,5 to 8 cm tall and
4-10 cm in diameter. The juice is watery (latex absent).
Tubercles: Conical, soft, flaccid and pliable, rounded apically,
dull blue-green, 1-2,5 cm tall, basal diameter 0,7-1,2 cm, axils naked.
Areoles: 1,5-2 mm in diameter circular to elongated
Central spines: Almost always one, (0-)1(-4) up to 1,7 cm long,
yellowish to reddish, spreading, 1 hooked, while the second central
spine(s) – if present - are straight.
Radial spines: 10-18(-24) slender white 0,8-1,6 cm long straight
silky and slightly pubescent.
Flowers: Unlike most mammillarias, this cactus bears large
funnel-shaped flowers up to 4 cm in diameter, white with pink mid-veins.
Pericarpel green 3-5 mm long, tepals lanceolate, filaments whitish to
pinkish-green, style pinkish-green up to 2 cm long, stigma lobes 6-10
Blooming season: March to May
Fruits: up to 2,2 mm long, club-shaped red. The fruits
Seeds: 1.2-1,4 mm large, black.