mcvansoest wrote: ↑Tue Apr 11, 2023 11:15 am
I am always a bit surprised when people are talking about vera hybrids... I guess I have gotten the very occasional seed pod on inflorescences of my vera clump, but based upon observations of the many hundreds (if not thousands) of plants they are growing in the landscape on the university campus where I work (and throughout the greater Phoenix area as whole for that matter), I am pretty convinced that when people say this plant is mostly sterile that they are correct - which would be a strong indicator that it is likely a hybrid or like the domesticate Agaves a product of human intervention.
mcvansoest wrote: ↑Tue Apr 11, 2023 11:15 amThe fact that these plants pretty much flower at the same time en masse suggests to me that at least the plants grown throughout the Phoenix area are probably derived from a very limited number of clones - this plant has so little actual variation that propagation by offsets (clones) is way more likely to have been the propagation path throughout its long history than active seed based propagation.
scarce seed pods could indicate sterility because of hybridization, but it could also indicate...
1. that the aloes are all clones that aren't very interested in inbreeding
2. the absence of an effective pollinator
when i littered my front yard with pups from my variegated arborescens, with the goal of facilitating variegated hybrids with my other tree aloes, i had the same question. even though i also had a green arborescens, seed pods were few and far between. one issue is that the variegated arborescens blooms a lot earlier than the rest of my tree aloes. i managed to end up with a variegated arborescens seedling which i also stuck in the front yard. when it began to bloom i don't remember a noticeable increase in pods. but when i found and bought another variegated arborescens then there was a noticeable increase in arborescens seed pods. it's hard to say if there's much difference in the new variegated arborescens' form or variegation, since i still only have it in one spot. the flowers might be a bit nicer, but maybe it's just my imagination. the pods though are definitely different... they are larger, reddish and a lot more numerous.
in this case the pod scarcity wasn't because of hybrid sterility, or a lack of effective pollinators, it was because of a lack of adequately different aloes blooming at the same time.
last year my long-suffering ferox managed to bloom and it did so when my arborescens was blooming. i thought for sure my ferox would be loaded with pods since the two aloes are compatible and were blooming a few feet from each other. but for the heck of it i spent a few days pollinating the ferox with variegated arborescens pollen. much to my surprise and disappointment, the only pods i got were from the flowers i pollinated. in this case the issue had to be a lack of effective pollinators. evidently we are going to need larger hummingbirds.
since vera and arborescens are such prolific puppers it makes sense that most of them are going to be clones. even when seed is available most people would prefer a pup. the colonization of clones is an interesting topic. whenever "i" make a new aloe hybrid i wonder how much its survival will depend on how quickly/prolifically it pups.