Black discoloration from the growing point.

David48 · Post by **David48** » Mon Jul 25, 2016 2:46 pm

I purchased an Acanthocalicium (Echinopsis) thionanthum online a few months ago. It developed a black area from the growing point, but it is not spreading, the new growth is coming from the apex and so gradually the black area is going to move down the plant. No other plants have been affected. At first I thought it had got scorching at the apex, perhaps from some water collecting in the depressed region, but it is not scorching. Neither is it a progressive rot, but maybe it is a fungus which has only attacked the outer skin then not developed further.

I contacted the seller who immediately refunded my purchase, stating that he also had this develop on his remaining specimens of this species, and he had thrown the plants away, advising me to do likewise with mine.

Any ideas about what has caused the black, and whether I am risking my collection if I hold onto the plant?

cactushobbyman · Post by **cactushobbyman** » Mon Jul 25, 2016 8:06 pm

At first I would say cold damaged. I have an outside Pachycereus pringlei I transplanted late last fall and the same damage soon appeared and I thought it had frost damage, but the growth tip did not die. This spring new growth appeared at the growth tip and it still has the same dark area but as a ring around the plant. I also thought it may have been shock from being transplanted into full sun, not knowing how much sun it received from the previous owner. Just another beauty mark.

David48 · Post by **David48** » Tue Jul 26, 2016 9:24 am

It will not have had cold damage in my care, (indoor windowsill with some outside daytime spring sun in the garden) and the black was not there on its purchase. Since the same thing has happened with the supplying grower, it seems to have had a common experience with its siblings. Thank you for suggestions. If it is some marking as a result of scorching I think I will keep it, with its "beauty mark". But if there is an infection, potentially with spores which could return, then I am inclined to take the growers advice.

adetheproducer · Post by **adetheproducer** » Tue Jul 26, 2016 4:31 pm

Could be a Helminthosporium cactivorum infection.

Black discoloration from the growing point.

Black discoloration from the growing point.

Re: Black discoloration from the growing point.

Re: Black discoloration from the growing point.

Re: Black discoloration from the growing point.