Description: G. monvilley
is a (usually) solitary
Stem: Flattened or
globular, dark-green, grey-green to olive green, up to 20 cm in
diameter, up to 8 cm tall. (but in
cultivation plants can grow up to 30 cm in diameter)
Ribs: 10-17(-20), broad,
obtuse, tuberculate with chin like protrusions.
Spines: Stout, thick, slightly curved, yellow with usually
reddish bases, often translucent , but also orange, black or reddish.
Radial spines: 7-13, 3-4 cm
5-7 up to 12, but usually less in young plants,
flattened against the body.
Central spines: Usually absent, or 1 to
Flowers: Are some of the largest in this genus, often growing
larger than the plant!, funnel-shaped 4 to 8 cm long and
wide, white flushed with pink or pink and
often double petaled.
Blooming season: Summer,
It takes 5-6 years from seed before flowers.
Fruit: Green that became yellowish at maturity, globose, up to 2 cm
Seeds: Up to 1 mm brownish-red.
There are a number of
different forms of
this highly variable cactus species, but not all are universally
recognized. Some authorities recognize the following
Subsp. monvillei. has 7-13 curving, ± compressed
radial spines usually yellow (Origin Córdoba
Subsp. horridispinum Has 10-12 strong stiff radial spines
Subsp. achirasense Has 10-12 radial spines almost flat
against the plant body (Origin San Luis province)
Subsp. Brachyanthum Has approx. 7 spines (Origin San Luis