North central Arizona habitat

[peterb]

First of all, would like to clarify that this forum is intended for places where cacti grow, if I have it right. Botanical gardens and habitat, in particular. There is a separate forum for threads related to purchase cacti and succulents. Not that this sort of thing is all that important, but there has been some crossover recently.

Have been spending some time pretty much directly north of Phoenix exploring habitat around New River. Amazing scenery and plants. Here's a link to the Facebook gallery, a public link, no FB account needed to view.

https://www.facebook.com/media/set/?set ... 4cf3846edb" onclick="window.open(this.href);return false;

hope you enjoy.

peterb

[Saxicola]

Great pics! You've got a talent for taking them. I need to get out and explore the Sonoran desert at some point. I'm closer to the Mojave, which is nice, but it doesn't have the same level of diversity.

About your comments on this forum. I think the problem is that there really is no other forum that deals with purchases of cacti and succulents. There is one about swapping plants but not buying and selling them. Plus, "nurseries" are mentioned in the description of this forum. I have long thought there should be a separate forum for things related to buying and selling cacti, and nurseries should be lumped into that. As it stands now it really is kind of this forum and General.

[peterb]

You're right, I thought there was a separate forum for nurseries. It's a thread under General "Great places to buy." Interesting. Glad you liked the photos!

peterb

[keith]

Peter have you been to Parker Cliffs East of lake Roosevelt ? Lots of the small white green agave's growing there that look like the ones in the pictures you took.

Cool pictures BTW

[peterb]

No, haven't been there, but that general area is on the list. Thanks for the tip.

peterb

[vlani]

What are those coccineus-like Echinocereus(-i?) with long tube?

The engelmanni tribe is a complete taxonomist nightmare up there.

[peterb]

Echinocereus yavapaiensis, a hexaploid quite distinct from either trigloch or coccineus for a variety of reasons. very interesting plants. The New River mountains are where some of the supposedly "distinct" geographical variants of engelmannii go to die. boyce thompsonii, apachensis, acicularis are all jumbled. To further confuse matters, a central spine form of E. bonkerae crops up sympatrically, only certainly distinguishable when in flower. (bonkerae is a diploid).

peterb

[vlani]

Interesting. The plumped-up stems do look different then coccinneus, but that is only if you seen lots of coccinneus.

What is your take of acicularis? It is supposedly some engelmanni form, but I always had trouble matching plants with names when it comes to that species. I can clearly see the difference between 'normal' engelmanni - like Death Valley plants, plants from Anza-Borrego - long-spoinned, as I remember only yellow form present, feels like they got one or two less ribs but I did not actually count, and the smaller northern form with short spines - like the plants on the West slope of Houserock valley. But I cannot match those 3 to names. Honestly, I thought acicularis is the name for Anza-Borrego plants?

[A. Dean Stock]

To add to the complexity of the E. engelmannii complex, a new species will soon be split off from E. engelmannii. This one is an ancient diploid. We are presently working on distinguishing it from the House Rock Valley and Arizona Strip material as well as populations to the west with morphometrics and chromosome counts.
Dean

[peterb]

I do not know with any certainty, but I suspect that some of the old variety names are nearly entirely worthless, but some of them may be worth reconsidering. I think a good standard to use for infraspecific taxa is their geographical isolation and relatively pure, non-intergrading characters. On this basis, it may be that acicularis is entirely worthless as a name, but howei or armatus or perhaps even chrysocentrus might be useful in some way. E. e. variegatus is meaningful in a very limited sense, but the plants begin to drift into other forms on all sides of the geographical range. E. boyce-thompsonii and apachensis are also very strongly defined in extremes, but very weakly defined as one heads away from their population centers. This creates a reality where one either wants to use the names only for the plants that very clearly fit the descriptions or just discard them altogether. In informal conversation, I am frequently saying something like "well, this looks like it has some variegatus in it, but maybe also some chrysocentrus." It's not useful beyond those educated guesses. The other issue is that some of the apparent differences in the field do not stand up under the scrutiny of multivariate analysis nor do they present very convincingly with herbarium specimens. It's hard to justify retaining names even at the infraspecific level that don't clearly apply to a lot of collected and observed material. Perhaps the most helpful thing to know about a particular Echinocereus engelmannii is where it is from. Here is a link to an interesting approach to trying to find some kind of distinctive molecular difference between Echinocereus engelmannii "var. munzii" and more widespread forms. Botanists continue to work on the complex. http://alyxia.umiacs.umd.edu/publicatio ... l_1996.pdf" onclick="window.open(this.href);return false;

peterb

[A. Dean Stock]

The populations of E. engelmannii that I've worked with are all very variable in almost all characteristics. The one group that seems pretty consistent is the small, grey plants that occur from House Rock Valley westward across most of the "Arizona Strip". The varietal name variegatus is probably misapplied to these plants but they do seem consistent enough to merit recognition. By contrast, plants once referred to as var. chrysocentrus in southwestern Utah are very variable. It is to be expected that varietal boundaries would break down at contact zones since they are all interfertile. Hard group to deal with but seem relatively simple after years of working with Opuntia species. The diploid populations, once recognized as var. purpureus, are recognizable but also are very variable with some populations being extremely small and in some ways resembling those on the Arizona Strip which are all derived tetraploids.
Dean

[peterb]

Some of the more isolated engelmannii in California seem tidier to me (armatus, howei, perhaps munzii which I have never seen in habitat). It seems like they are more isolated in California, occurring in specific patchy locales with less continuous ranges. Looking forward to learning more about that diploid in the future.

peterb

[GermanStar]

Here are more pics from the same general area: Habitat: First Foray into Arizonica-ville

We saw lots of fantastic succulents, but the E. yavapaiensis really stole the show, IMHO.

[AgavaSK]

Just WOW!

[vlani]

Dean the small grey engelmannii plants from Houserock valley slopes are actually not a small isolated group. I think it is more like a common Northern form - same kind of plant grow just East of Great Basin on Utah side, and if I remember correctly Tonopah's engelmannii are also of that type.