Hi there,
I'm wondering if you could help me with a cactus problem I have.
The species name could be Echinocereus websterianus, but I'm far from certain. The cactus is a cylinder in shape with several vertical limbs; flesh is green and has spines which are narrow, 5cm long (approx) and sharp. Hopefully this description will aid identification!
My problem is that near the top of the cactus on one limb, there is some discolouration that is black in colour. This discolouration is a thin band, but above this point, the cactus has shrunk. The affected area is not soft or mushy, but is actually quite hard, like a healthy cactus. The affected area is spreading down the limb, but not at a fast rate. Otherwise, the cactus looks entirely healthy except for some light green spots! But the affected area is spreading, causing me concern. It appears to be some form of rot, but with no indication of yellowing flesh or leaning as observed when mealy bugs cause rot (speaking from unfortunate experience).
Does anyone know what the problem with my cactus is and what action needs to be taken? The most obvious action would be to remove the affected area, but I'm not keen on doing this unless needed as I'll be creating an open wound and the growth point would be removed.
Many thanks for your assistance,
Steven.