What kind of opuntia are these?

[mjazz]

These were planted on the south side of a commercial building. A nearby river overflowed and the parent plants were actually underwater for a while.
As luck would have it, a few pieces got knocked off, so I salvaged them. They have a typical yellow flower similar to O. humifusa.

[fanaticactus]

Could they possibly actually be humifusa? I note you're in RI and it's a fairly common garden cactus here in the northeast.

[Peterthecactusguy]

hell in PA we had some growing like weeds.

[daiv]

I don't think that is O. humifusa as I imagine that species. I think this looks a lot more like O. macrocentra, but then it would have red centered flowers.

[mjazz]

Thanks to all. I have O. humifusa and they are quite a bit different, they have a sprawling habit.

[hoteidoc]

Agree with you, mjazz. Have humifusa too -- virtually spineless, pads smaller & slightly thicker.

[Peterthecactusguy]

if those aren't O. humifusa then what are they that would grow naturally in PA?

[hoteidoc]

Maybe they weren't "natural" -- maybe another cactus-freak ahead of their time! Us N'oreasters are counting on you Opuntia experts out West!

[Tony]

Could this be Opuntia macrorhiza?

[peterb]

I think these are phaeacantha. Do you remember if the flowers have an orange center or are they pure, light yellow? Also, do the pads fall prostrate and get very wrinkled in winter or does it pretty much retain its shape?

peterb

[CoronaCactus]

I'd guess phaeacantha or lindheimeri.

[mjazz]

I think these are phaeacantha. Do you remember if the flowers have an orange center or are they pure, light yellow? Also, do the pads fall prostrate and get very wrinkled in winter or does it pretty much retain its shape?

peterb

They have the orange center, like the humifusa. I think they droop a bit but don't fall prostrate and wrinkle.
Here is a picture of what I thought was O. phaeacantha in a different part of the yard. I took the pic because the fruits appeared to ripen before the O. humifusa: (Maybe it's not even O. Phaeacantha):

[peterb]

Hmm, I am used to humifusa being pure yellow. ?? I think the orange center increases the odds these are phaeacantha. Just my .02, of course, as only fools give flat out 100% positive IDs for Opuntia!

peterb

[hoteidoc]

Thanks from me too, Peter. I inherited 2 (positive) humifusa because no spines, wrinkle, lay flat & pure yellow flowers. Just a couple of weeks previous, I had bought (of course) what I have been calling humifusa (nursery selling clueless, but all the same characteristics, except orange centered blossoms), so I had been suspicious. Also throws an occas. spine across top of pad. Have been just as "neglected" as the other 2 (humifusa) & doing just as well thru past 3 winters now. Now I have (confirmed) polyacantha & a phaeacantha "Dark Knight" to watch this coming Spring

[mjazz]

Hmm, I am used to humifusa being pure yellow. ?? I think the orange center increases the odds these are phaeacantha. Just my .02, of course, as only fools give flat out 100% positive IDs for Opuntia!

peterb

I'll have to take some better pictures of what I'm pretty sure are humifusa. I posted some here at cactiguide earlier that I must have scanned before I got into the 21st century and bought a digital camera. I tried looking up earlier posts but pictures no longer showed up. But I'm positive they had the orange centers. Below are what I think might be humifusa (notice the spiny relatives to the right for contrast). I bought them online as an unidentified opuntia hybrid. When I got them in the pots they looked something like opuntia fragilis with rounded joints, but they grew into pads:

DSC00100.JPG (125.88 KiB) Viewed 1072 times

Here is one in another part of the yard:

DSC00102.JPG (58.35 KiB) Viewed 1072 times