werdermannianus is a (usually) simple stemmed small cactus with
bright yellow flowers. This species shares some characteristics with
Stem: Globular to slightly cylindrical, often flattened up to 13
cm tall and 10 cm in diameter, yellowish-green to green.
Ribs: up to 40, vertical, straight rounded with many small
Areoles: White, wooly and closely set one to each other.
Radial spines: About 15-20, setaceous, more or less erected,
whitish or yellowish 4-5 mm long.
Central spines: 4-partite yellowish or reddish (N.
ferrugineus) acicular, sharp and flexible up to 15 mm long, the
lowest of them longer and pointing downward.
Flowers: About 6 cm long, up to 7 cm in diameter, pale yellow and
satiny. Tepals lanceolate darker at the tip, style quite long rich
egg-yellow coloured, stigma lobes10-12 carmine red.
Seeds: With distinctive longitudinally-oriented fine striate
Remarks: The "forma mostruosa" (Monstous form):
This plant is a rare oddity with areoles merging to form concentric
lines. The epidermis is harder than in the normal Notocactus and cracks
easily but this is not a defect and the plant will not suffer for this,
and also the fact that the body splits open
permits to the plant to develop original and strange shapes.
The epidermis is harder than in
the normal Notocactus and cracks easily but this is not a defect
and the plant will not suffer for this.
It is easy to grow. They like a warm bright location, does great in
partial shade avoid full sun. They need good drainage and prefer a
neutral to slightly acidic compost with plenty of extra grit. Water
during the summer. Best if watered with rain water. Keep above 0°C and
rather dry in winter, rot easily if the substrate is wet and cold, tends
to lose its roots in winter.
Propagation: Grafting or