Melocactus arcuatispinus A.J. Brederoo & Eerkens, Succulenta 62,
79, 1983
Scientific name:
Melocactus zehntneri
(Britton & Rose) Luetzelburg
Origin: Northeastern Brazil ( caatinga of
Pernambuco State).
Habitat and ecology :
Grows just sit in narrow cracks of solid rook rows in
dry areas where rainwater quickly disappears. The fruit of this plant
sometimes remain embedded inside the cephalium bristles, with seeds
waiting, perhaps, for the parent plant to die and provide a bit of
organic matter for them to germinate in their surprisingly inhospitable
environments.
Conservation status: Listed in
CITES appendix 2.
Common Name: Turk’s cap,” “melon cactus” (or
simply “melon”)
|
The most
remarkable part of a Melocactus is its
cephalium a bristle-coated structure on the summit of the plant,
only Melocactus, and the similar genus
Discocactus
possesses this type of permanent, apical, hatlike appendage. It’s only
when a Melocactus reaches maturity that the cephalium begins to
grow. Cylindrical, with a diameter distinctly smaller than that of the
plant body below, the cephalium will keep growing for the rest of the
plant’s life, but the body of the plant stops growing the moment the
cephalium starts to form. . As the plants age the cephalium doesn’t
increase in circumference it will steadily grow taller
Cultivation: These cacti are not the easiest
things to grow and aren’t plants for beginners. Melocactus
arcuatispinus (zehentneri) grows from April to October, it can’t
endure long stretches of total dryness, and also too much water will rot
it, as its weak root systems tends to be inefficient at sucking up water
from wet soil. Nonetheless, again as a result of their tropical origins,
they need a fair amount of water, but allow the soil to dry quite a bit
before watering again. Melocactus rests from October to April but can’t
stand cold, or even fairly cool temperatures, so is indispensable to
keep it above 8-12°C at all times, severe damage or death occurring at
temperatures that the great majority of cacti wouldn’t mind in the least
and prefer more frequent water in winter than other cacti, say once a
month. Do not feed in winter.
The root system is weak and generally resents being repotted and can
take a long time to re-establish. The soil mix should be very quick
draining, prefers very bright light, not as much as the most arid
growing cacti, but plenty nonetheless.
Propagation: Exclusively by Seeds. Sow in
February-march in a light, sandy, porous soil. Cover germinating tray
with glass to prevent seed from drying out. Germination is most
successful at a temperature of 18 to 22° C. |