I was horrified when suddenly I noticed a branch on my Alyogyne Huegelii...blue Hibiscus...full of black bumps!!!! Upon further examination I found it over all the branches but one young one, all the way down to the soil. They were clustered in places and more spread out in others. Some about 1/8 inch. Also, some were not totally black, but the overall look was blackish or gray. I took them all off by hand. Some were squishy and many were dry and crispy. None of my other plants have them thank goodness. I don't know if my picture is too dark, but the silhouette may be telling...Some almost look fuzzy!!? This was the worst branch.

I've been using both ABS and PVC for over 25 years and in different places across the US, each with different rules and regulations, most of which is not based in solid science. ABS hands down beats PVC in direct sun and also under homes in indirect sunlight. In Hawaii, PVC becomes brittle within a year. It pits, shatters, cracks and crumbles. ABS doesn't do any of that. As an inspector I see this every day. An ABS roof vent pipe can last 15 years in heat and sun without being painted. ABS is more expensive than PVC. While ABS is not used for water pipe, PVC and not CPVC is still being used as water supply in Hawaii. Both should be outlawed as toxic for water. Sched. 80 PVC fairs much better than Sched. 40. Sched. 80 is grey and a bit softer. Yes about the primer purple for inspections. On Farms and ranches you can see crumbled remains of long runs of original PVC, right next to newer and flexible and safer HDPE tubing. If one looks close at larger diameter ABS, you can sometimes see its "foam" core. Like one comment said - If you hit ABS with a hammer, it's unlikely you'll break it, but try that with PVC and it will break easily - shatter even. Once a plumber from Australia told me that some places banned ABS because of the gases released when it burns in a house fire or when it's cut too fast by plumbers. I'm sure the health of plumbers was not on a politicians mind when banning ABS. ABS will burn continually once it starts, whereas PVC supposedly self extinguishes. Not sure that burning carpet and every other thing in a house fire is any less toxic. But to answer the question - ABS is much more expensive (in Hawaii anyway) than PVC. And maybe in the end its the same because you'll buy and replace 3 to 4 times PVC to 1 time ABS. And seriously, it's just plain greed when a 3" ABS cap fitting that used to cost 2-5 dollars is now over $20 in 2024.

Don't get too disappointed. I've found Echeveria 'Chroma' loses that pretty day glo coloring overtime and ends up being a boring brown little echie. I just threw away an old dull one a couple months ago. When I first bought the one below it looked very different. You can see a hint of its former self. There is an echie called Echeveria 'Rainbow' that's pretty amazing when it comes to different colored leaves. E. 'Rainbow' is a variegated version of E. 'Perle Von Nurnberg'. Pic from World of Succulents;)

Previous roof job would be my guess too. Pieces fall through the cracks in the roof sheathing when roofers are removing everything up there.