Habitat: Sinagua Central

#1

Two separate hikes today at opposite ends of Southern Sinagua country in the Verde Valley. One site is fairly isolated and holds three distinct agave domesticate taxa growing very near a cute little hilltop pueblo. This ancient agave farm is holding up fairly well in the face of harsh realities of anthropogenic climate change.

Our other stop represents a far more complex situation. Here there are two types of agave domesticate, along with a locally rare cultivated Agave parryi site, and other agaves naturally occurring. Sadly, the cultivated A. parryi site is now deceased beyond any hope of recovery. Not especially surprising, but sad nonetheless. And the two agave domesticate taxa are in steep decline, with an 80% reduction in plant numbers from just 6-7 years ago. It was a veritable graveyard of agave stalks.

Naturally occurring agaves here (and the surrounding area) are unusual. I believe these are (were?) A. chrysantha, heavily introgressed with (now feral) products of ancient horticultural development, to such an extent that these are no longer sensu stricto A. chrysantha. I had instructed and directed a prominent Arizona agave taxonomist in regard to these plants some years ago, and now hear thru the grapevine that she refers to my discovery as “A. beaverensis” and is in possible pursuit of a formal description. Frankly, I am not convinced this situation merits a formal description. Agaves here are too diverse in regard to flower morphology to meet traditional criteria for a formal description in my opinion, and also in my opinion, remain sensu lato A. chrysantha.

So, one site two thumbs up, the other not so much, but a lovely wildlife encounter on our way out helped alleviate the sting.

: A. verdensis; FuzzyPic_Site 002.JPG (584.64 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 004.JPG (661.72 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 008.JPG (481.73 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 010.JPG (664.24 KiB) Viewed 694 times

: A. phillipsiana; FuzzyPic_Site 013.JPG (536.2 KiB) Viewed 694 times

: A. delamateri; FuzzyPic_Site 025.JPG (549.38 KiB) Viewed 694 times

: A. delamateri; FuzzyPic_Site 027.JPG (565.5 KiB) Viewed 694 times

: A. delamateri; FuzzyPic_Site 029.JPG (590.97 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 030.JPG (574.35 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 032.JPG (514.88 KiB) Viewed 694 times

: A. verdensis; FuzzyPic_Site 035.JPG (587.82 KiB) Viewed 694 times

: Local digs; FuzzyPic_Site 041.JPG (388.98 KiB) Viewed 694 times

: A. aff chrysantha; FuzzyPic_Site 052.JPG (611.14 KiB) Viewed 694 times

#2

Continued from previous post...

: Gilia flavocincta; FuzzyPic_Site 060.JPG (650.59 KiB) Viewed 693 times

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: Agave stalk graveyard; FuzzyPic_Site 069.JPG (599.14 KiB) Viewed 693 times

: A. delamateri; FuzzyPic_Site 075.JPG (614.59 KiB) Viewed 693 times

: A. delamateri; FuzzyPic_Site 078.JPG (557.81 KiB) Viewed 693 times

: Local digs; FuzzyPic_Site 084.JPG (186.5 KiB) Viewed 693 times

: A. parryi husk; FuzzyPic_Site 088.JPG (612.93 KiB) Viewed 693 times

: More A. parryi husks -- there were no survivors.; FuzzyPic_Site 089.JPG (719.21 KiB) Viewed 693 times

: A. aff chrysantha; FuzzyPic_Site 092.JPG (731.13 KiB) Viewed 693 times

: Gopher snake; FuzzyPic_Site 102.JPG (730.04 KiB) Viewed 693 times

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Paul S · #3

What is the purple flower, please Ron?

toditd · #4

Paul S wrote: ↑Fri Apr 05, 2024 11:57 am What is the purple flower, please Ron?

The flowers are a species of Gilia, most likely Gilia flavocincta.

#5

To elaborate briefly on the A. chrysantha issue referenced above, this is an unusual taxon, at least relative to other AZ agave taxa. Other than a relatively compact area around the type locality, there is very little "pure" chrysantha to be found anywhere. There are broad patches south and east of the type locality introgressed with A. palmeri, and virtually all chrysantha in the northern half of its range are introgressed to some various degree with A. parryi.

Then there are broad areas where chrysantha appears to be introgressed via ancient cultivation efforts. In addition to the area referenced above, nearby Agua Fria National Monument is another one of these, and there are others. So we have parryi, palmeri, and domesticates horning in on chrysantha genetic dynamics, sometimes separately, sometimes in sequence, sometimes in unison. Evidence for this manifests primarily in the form of deviant flower morphology.

A. chrysantha flowers are unique (or nearly so) in at least two ways. They are very small, much smaller than flowers of any other paniculate agave in AZ, and they feature dramatically upright tepals, a trait they share with A. palmeri. Upright tepals allow flowers to serve as nectar reservoirs in order to attract larger pollinators; bats in the case of palmeri and hummingbirds for chrysantha. In some areas in and immediately adjacent to archaeology sites, flowers retain the small size and upright tepals which define them as chrysantha, but many (not all) are the wrong color (yellow rather than golden orange) and feature tepal callouses. These are features of A. palmeri and A. shrevei, as well as 4 of 5 formally described AZ agave domesticates, and the distribution and frequency of these characteristics is wildly uneven across individual populations, let alone different sites, suggesting fairly recent introgression.

I could go on and on with this, but I doubt anyone is interested in reading a voluminous 100-page tome detailing increasingly tedious minutia regarding a single agave taxon. Though I'll reserve the right to expound upon this in somewhat more detail in the near future, so consider yourselves warned.

Gafoto · #6

Any idea why the parryi cultivates disappeared? The population I visited near Patagonia was in an equally odd and low location but was doing well in a clonal sense. Has the Verde Valley gotten unusually hot and dry? Usually parryi isn’t shy about sending out those unners.

Those verdensis specimens have to be the nicest I’ve seen photos of. Lovely vase-shaped leaves with those nice fine teeth. I’ll have to give those a try here in Utah some day. My chrysantha and palmeri didn’t love the snow but they were small and did survive.

Meangreen94z · #7

What are the distinct features that differentiate verdensis, phillipsiana, and delamateri in the above specimen?

#8

Gafoto wrote: ↑Fri Apr 05, 2024 5:26 pm Any idea why the parryi cultivates disappeared? The population I visited near Patagonia was in an equally odd and low location but was doing well in a clonal sense. Has the Verde Valley gotten unusually hot and dry? Usually parryi isn’t shy about sending out those unners.

Those verdensis specimens have to be the nicest I’ve seen photos of. Lovely vase-shaped leaves with those nice fine teeth. I’ll have to give those a try here in Utah some day. My chrysantha and palmeri didn’t love the snow but they were small and did survive.

Fried and died. It was always a marginal site, parryi there were the smallest I've seen. The Sonoita area always gets tagged by summer monsoons, so plenty of cloud cover and precip, even during the worst summers. Not so much for the rest of the state.

#9

Meangreen94z wrote: ↑Fri Apr 05, 2024 5:27 pm What are the distinct features that differentiate verdensis, phillipsiana, and delamateri in the above specimen?

A. verdensis is easy to pick out by virtue of numerous evenly spaced, needle-like marginals -- they're quite distinct from virtually every other agave I've seen. Delamateri and phillipsiana somewhat resemble each other, but are twice the size of verdensis. Phillipsiana bears a strong resemblance to palmeri, while delamateri greatly resembles shrevei. Phillipsiana is distinct from delamateri by virtue of narrow green leaves, compared to those wider and bluer. In the case above, the only phillipsiana remaining at this site were small 1-gal sized offsets.

Also, inflorescence and flowers of each are distinct.

Papahuel · #10

A new habitat thread, with a little taxonomic intrigue thrown in for good measure, today is a good day. (you would definitely have readers of that 100 pages of minutia).

Sad about the parryi, but I see why, they are struggling hard for me down at even lower elevation. At least they have introgressed, so they may be gone, but they aren't.

I'm 100% calling BS on naming if that introgression does get full taxonomic recognition Agave parkeri all the way (although I would think it far more apt if that name went to one of the wild and wonderful domesticates you have pictured).

Taxonomists are amusing, they definitely strike me as equal parts scientist and politician.

Meangreen94z · #11

Papahuel wrote: ↑Sat Apr 06, 2024 12:50 am A new habitat thread, with a little taxonomic intrigue thrown in for good measure, today is a good day. (you would definitely have readers of that 100 pages of minutia).

Sad about the parryi, but I see why, they are struggling hard for me down at even lower elevation. At least they have introgressed, so they may be gone, but they aren't.

I'm 100% calling BS on naming if that introgression does get full taxonomic recognition Agave parkeri all the way (although I would think it far more apt if that name went to one of the wild and wonderful domesticates you have pictured).

Taxonomists are amusing, they definitely strike me as equal parts scientist and politician.

That species name does have a good ring to it.

Paul S · #12

Papahuel wrote: ↑Sat Apr 06, 2024 12:50 am Taxonomists are amusing, they definitely strike me as equal parts scientist and politician.

It was been said that taxonomy is not so much a science as a war zone. And there is no bloodier battlefield than the naming of cacti and succulents.

#13

Paul S wrote: ↑Sat Apr 06, 2024 7:37 am
Papahuel wrote: ↑Sat Apr 06, 2024 12:50 am Taxonomists are amusing, they definitely strike me as equal parts scientist and politician.
It was been said that taxonomy is not so much a science as a war zone. And there is no bloodier battlefield than the naming of cacti and succulents.

In my small experience in this arena (very small), individual recognition trumps science in dramatic fashion. The story seems far less compelling than who is doing the telling. I can't tell you how disappointed I've been to watch this narrative unfold time and again. Oh well...

#14

I’ll try to elaborate on my theories about how this corruption of naturally occurring A. chrysantha by ancient horticultural efforts may have occurred. It might at first seem obvious that corruption resulted from interactions with large agricultural fields of cultivated A. verdensis and/or A. yavapaiensis in the area, and those formally described domesticates probably do have a hand in this, but I suspect the issue is far larger.

In this area, extant A. verdensis and A. yavapaiensis populations suggest a time when cultigens were farmed, possibly in very large numbers. It’s probably safe to assume that the small number of plants remaining today represent far less than 1% of the number grown under the watchful eye of those same local farmers who developed them. And these were finished products, which their developers apparently attempted to sterilize, in order to lock in those characteristics for which they selected in their development. That they didn’t actually succeed is beyond the point, they did manage to come pretty close. A. verdensis and A. yavapaiensis are reproductively compromised, and severely so. Under the best of conditions, each produces no more than 5% of the seed one might expect from agaves naturally occurring. My point of course, is that the impact of reproductively compromised agaves on local populations may have been of limited consequence.

But let’s put that narrative on a shelf for the moment, and instead, try to imagine in as broad a context as possible those circumstances which led there. I’ll skip ambiguous background details, but at some point, folks in the Verde Valley began experimenting with and developing their own agave cultigens. After all, A verdensis didn’t just drop out of a hat. They were selecting agaves across multiple generations for certain characteristics, and may have gained access to A. palmeri and A. shrevei for that very purpose via trade. As time went on, those efforts were getting closer and closer to a desired result, all the while producing agaves they greatly preferred as pit roast fodder over naturally occurring A. chrysantha.

So now they were growing fields of different fully fertile agave cultigens as their development process proceeded toward an as yet unseen, and eventual end of reproductively compromised A. verdensis and A. yavapaiensis. They were experimenting with diverse products, and growing them in numbers that dwarf the small number of naturally occurring A. chrysantha along the periphery of the region. This is no hotbed of naturally occurring A. chrysantha here, it is just a bit player at the northwestern edge of its range.

This is the period in which I suspect introgression from cultigens entered the local agave landscape. There may have been a hundred fully fertile cultigens for each agave naturally occurring, and a few generations later, early domesticate precursors gone feral and pollen from other farmed cultigens left an indelible mark on the local natives. Over time, the best/strongest of these radiated outward, and became indistinguishable parts of the natural agave landscape. Since A. chrysantha was only doing so-so here at the edge of its range, it would have been especially amenable to the right mix of nucleotides improving its lot. Sometime later, these folks eventually land on A. verdensis and A. yavapaiensis, which add their own genetic dynamics to the mix to more subtle effect.

For the record I’ve seen similar corruption of local A. chrysantha populations in areas in which the only domesticate found is A. delamateri, which, due to ploidy issues resulting in triploid progeny, cannot have played a role in this. In that instance, it could only have been the development process, rather than the final product, which led to this outcome.

Anyways, hope you'll forgive my rambling. This is really little more than wild conjecture on my part, toward an end of constructing a plausible narrative.

#15

Two separate hikes very near the same area in the OP brought us to three new rock art panels and four happy healthy domesticated agave sites. These include A. delamateri, A. verdensis, and A. phillipsiana, each of which being crafted and grown by indigenous Native Americans many hundreds of years ago. I was especially gratified by the moderate condition of the A. phillipsiana site, which is exceedingly rare in the area, and facing regional extinction.

: Object of hike #1.; Sacred 000.JPG (363.89 KiB) Viewed 285 times

: A. chrysantha; Sacred 001.JPG (597.75 KiB) Viewed 285 times

: A. chrysantha; Sacred 007.JPG (456.16 KiB) Viewed 285 times

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: O. chlorotica; Sacred 038.JPG (564.8 KiB) Viewed 285 times

: Sacred Mountain; Sacred 040.JPG (452.7 KiB) Viewed 285 times

: A. chrysantha; Sacred 049.JPG (689.32 KiB) Viewed 285 times

: A. chrysantha × A. delamateri; Sacred 054.JPG (688.48 KiB) Viewed 285 times

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: A. delamateri; Sacred 066.JPG (610.9 KiB) Viewed 285 times

: A. delamateri; Sacred 068.JPG (606.87 KiB) Viewed 285 times

#16

Continued from previous post...

: A. delamateri; Sacred 069.JPG (589.77 KiB) Viewed 285 times

: Local digs; Sacred 074.JPG (616.72 KiB) Viewed 285 times

: A. verdensis w/agave mite lesions.; Sacred 076.JPG (503.61 KiB) Viewed 285 times

: Same A. verdensis as in prior snap, demonstrating a clean core, so this agave cleared its mite infestation on its own.; Sacred 077.JPG (333.18 KiB) Viewed 285 times