G. ritterianum has attractive
stems and freely produces nice satiny white or pink flowers with rosy
throats. This plant is still rare in collections,
but, like many of its genus, it is easy to
is a variable small cactus, usually solitary
to occasionally clustering.
discoidal 4-4 cm tall, 8-11 cm in diameter, clear grey-green,
that tinges reddish in full sun.
Ribs: 10-12, with tranverse furrows, divided in pronounced
humped, chin-like tubercles.
Spines: 7-9, up to 2,5 cm long, white,
yellow or pink/brown, curved against the
plants body, one directed downward , others to the sides
Central spine: None, or sometimes one,
straight, rigid, curving backward.
Flowers: Near the apex, up to 6,5 cm long and 7,7 cm in diameter,
usually satiny white with rosy to violet
throats, but also pure white, pink
Blooming season: Flowers appear recurrently from April to autumn.
Fruits: Pear shaped, bluish.