The Eriosyce laui is a very peculiar cactus that looks like nothing
relationships among the cacti remain unclear, and the monotypic genus
Rimacactus has been erected for it.
Very small soft-bodied
cactus, covered by whitish wool. In cultivation
it will form
a clump of heads
approximately 7cm in diameter, that is far larger than a plant would
ever be in habitat.
Stems: Small, slow
or reddish, up to 3 cm in diameter, but until the new plants or offsets
are about 4 to 5 mm in size, they are mostly hidden by the thick wool.
clumps very freely, eventually becoming somewhat
elongated in cultivation.
Ribs: Divided in tubercles.
Areoles: Very wooly.
Spines: Short, 9-13, white.
Flowers: Funnel-shaped, right in the crown of the plant, they
are about 2 cm in diameter, sulfur yellow with a reddish line on the
The flowers open from early June onwards.
already when young,
synchronised flowering of the whole plants taking place over one
or two days, remaining open for about three or four days.
Fruits: Naked, somewhat skittle-shaped, immature fruits
that are about 15
mm long, by 8 mm in diameter,
with a rough, shiny black surface.
maturity, they elongate and turn pink, and became u
p to 32 mm long and 12
mm wide, looking just like fruit of Islaya. The withered flower remains
continue to stay attached to the fruit.
Cultivation: They are extremely
and are said to be very slow from seed.
They are commonly seen
grafted to avoid
root rot problems, and in order to speed growth.
Frost Tolerance: Likes warmth (recommended minimum winter
temperature 5° C). But
a plant kept perfectly dry can easily
at winter night temperatures below 0° C .
Sun Exposure: Suited for
sunny, bright exposure;
it can tolerate
light shade. Suited for
diseases: E. laui is
prone to rot, therefore,
underpot in a smaller container filled with very
Seeds or graft. Seeds can be sown in the
spring or summer. The seedlings should not be disturbed until they are
well rooted, after which they can be planted separately in small pots. This
plant is frequently grafted on Pereskiopsis as a tiny seedling,
which has an accelerated growth rhythm.