Characteristics): M. moelleriana
is a small
cactus that appears above the ground as a squat, spherical stem,
completely covered by very strong hooked spines, and
usually solitary. In cultivation the plant's
stem may be
is also one of the more difficult to grow, as it is subject to losing
its roots. The yellow spined form is often labelled M. cowperae.
Stem: Flattened globose to short cylindrical,
up to 10 cm in diameter, 13 cm tall, glossy green. Tubercle firm,
cylindrical to ovoid with woolly axil. Without latex.
Radial spine: 35 to 50, white with yellow bases, needle-like, 7 - 9
Central spine: 8 to 10, honey yellow to dark reddish brown, with
yellow bases, 20 - 30 mm long, lower 2 - 4 hooked, upper ones shorter
Flowers: White or light pink flowers, with darker midveins, up to
1.8 cm in diameter.
Fruit: Club shaped, greenish white, to 15 mm long.