Agudo, Serra Geral, Rio Grande do Sul, Brazil (Notes: = FR1269, MGH73)
Description: Notocactus horstii is a
solitary or slowly clustering medium sized barrel cactus with many
flowers in early spring.
Stem: Flattened or spherical up to 10 cm tall and 15 cm in
diameter (but in cultivation plant tends to elongate and can grow up to
30 tall) The crown of the plant is covered in spiny white wool.
Flowers: Either orange or yellow for what used to be Notocactus
horstii and violet-purple for what used to be Notocactus purpureus
(which is now Parodia horstii fa. purpurea) up to 3.5 cm in diameter.
Blooming season: Spring.
This variety was called Notocactus purpureus.
The purple-violet flowers are stunning
Cultivation: They like a warm bright location,
and do great in
partial shade. Avoid full sun.
During winter's rest period they should be dry
and cool. It is best to avoid any frost, but during the winter the
temperature can be as low as 2° C without any harm,
as long as the
compost is very dry. They like only a short winter's rest.
If the soil
is allowed to be dry for too long, root loss could follow but equally the
same result would occur if the plants are both wet and cold. Cold spots
can mar its epidermis in cold damp conditions. They need good drainage and prefer a
neutral to slightly acidic compost
with plenty of extra grit and iron feed help to delay the onset
of basal corking.. Water and feed during the summer.
watered with rain water and given an occasional tonic of sequestrated
iron. A well grown plant is a fresh glossy grass- green,
contrasting with reddish spines.
Propagation: Usually by seeds as it seldom produces