Tropical Treasures of the Desert

[Silas_Sancona]

After 4 days spent baking in Phoenix, and a couple days playing catch up in the garden, cleaning and sorting collected seed, and at work, I finally get a chance to sit down and share a few highlights of this past weekends research trip with everyone.

While part of the trip there was a get away to enjoy the desert, the other half was set aside as time to further document some of the most unique of Arid-type tropicals. One, a species of Lignum Vite, has been on my must see in bloom list for some time. Despite the record 114F high there last Saturday, no one, except maybe my dog seemed bothered.

Guaiacum coulteri- Guayacan:
Slow growing native of the Thorn Scrub/ dry Tropical Forest region of Sonora Mexico on south. Considered threatened due to over logging in habitat. A species currently being researched for potential medical properties. Considered hardy to about 28-ish, specimens id encountered in Glendale this past march only suffered die back to the most exposed branch ends. Currently trialing a 3gal specimen.

Flower detail. Each flower measures roughly 1" across.

Seed capsule and seed detail. The bright red Aril which covers each seed is said to attract birds which help distribute them. Was able to acquire seed for propagation trials.


Acacia williardiana- Palo Blanco:
Slow growing native of gravely plains/washes in Sonora. Another tree whose cold hardiness is up for debate. When I was in the area this past March, I found specimens around town which had been torched (Glendale xeric demo garden specimens) and others which were untouched (near Papago Park and around Tempe) Checking on all specimens and documenting additional, all showed no signs of damage. Suggested cold tolerance falls somewhere between 27-25F. I myself consider this tree a spectacular Paper Birch stand in for obvious reasons. Seed id purchased failed to germinate under all conditions I tried and have heard that seed doesn't stay viable for long after maturing. Was able to acquire some fresh seed to test again. Working on acquiring a larger specimen for in-ground trial.


Trunk and Bark detail.

Leaf Detail, leaves are at the end of modified, twig-like stems.


Overall detail. Individual specimens can vary in shape. Saw specimens planted in groups of 3, much like Birch are.


Flower detail.

Edited August 22, 2013 by Silas_Sancona

[Silas_Sancona]

Geoffroea decorticans- Chilean Palo Verde:

Interesting Palo Verde like tree from South America hardy to the mid/high teens. Because it is a Legume, I assumed I would find the typical bean-like seed pods below this tree while researching this specimen in Glendale. Seeing what looked like brown, hard shelled cherries scattered on the ground, I did not make the connection until I jumped online back at my Hotel. Strange that it is one of the few Legumes which produces a single, drupe-like fruit which is considered edible and possesses a jelly-like coating around the hard cherry-pit like seed hull. The coating smells a lot like molasses imo.

While the tree itself could be considered messy (lots of fruit drop/branch tips end in a spine) the bark pattern alone might be interesting enough to include.

Overall detail

closer up. Trunk detail

Bark pattern

Caesalpinia cacalaco- Cascalote:

While a fairly common sight around Phoenix, I felt like including it here simply because of the distinctively different look of the foliage. While older specimens will produce knobby spines along the trunk and branches, it is another great arid-type of tree well suited for a water wise garden setting, or among a group of Mexican Cycads, especially when in flower, in Winter.

Foliage Detail

Flowers

A couple more shots of Guaiacum coulteri, can't wait until mine flowers.

In a land of extremes where water is often scarce and the sun reigns supreme, it is always amazing to discover hidden gems reminiscent of wetter parts of the tropics among the cactus and Braheas. -Nathan-

Edited August 22, 2013 by Silas_Sancona

[sgvcns]

A reminder of the differences I treasure.

Thank you for the knowledge that is new.

Pretty is not limited to what I chase.

Thanks

Steve

[palmmermaid]

Thanks for sharing. When the desert blooms it is spectacular. I am amazed at how much genuses are shared by the deserts of the southwest and our scrub areas here in Florida. While visiting Anza-Borego Park a couple of years ago, I saw relatives of our gumbo limbo, our lignum vitae, our opuntias, and others. And like the desert, our scrub areas are so different from the other areas in the state. The flora and fauna is very unique and quite varied. Always interesting to visit.

[Peter]

Great post!

[fastfeat]

Just landed in SoCal after a few days in AZ myself.

Grow Caesalpinia cacalaco as hot and dry as possible. Tends to be pulpy (though grows vigorously and flowers well in coastal OC). Train to single or very few trunks, otherwise, you'll find yourself cursing as you thin and raise the thorny tree. A little early investment will save much pain later.

Read about Geoffroea decorticans on AZT's site but haven't seen it-- looks like a tough tree.

Never tried germinating Acacia williardiana. Should be easy, but apparently not...Never seen it outside of low desert. I suspect would be tender in youth, gaining hardiness with age.

Best of luck.

Edited August 23, 2013 by fastfeat

[Silas_Sancona]

Thanks everyone! Its fascinating to see how many of these plants, among many others from similar regions across the globe, are connected. Curious if any of the other Bursera species are being grown successfully in Fl. My first assumption based in what I experienced when I lived there would be that the excess summer rainfall would be a challenge for some species.

Fastfeat, Great advise. I remember you mentioning these tendencies regarding C. cacalaco in a prior thread. The "training" aspect mirrors advise sometimes given for such trees as Tipuana tipu, or some of the Cassia/Senna species which can have a tendency to be a little weak/ unruly without early guidance. As for A. williardiana, I also assumed this species was confined to the low deserts until I sighted at least 3 specimens scattered throughout the Desert garden at the Huntington when I visited in May. Two were in bloom at that time there as well. While I didn't see it, there is also supposedly a specimen of Haematoxylon brasiletto in the Huntington's collection also. A specimen of this species id picked up back in March has done well for me here, thus far, even producing seed. As for A. williardiana, we'll see if acquiring fresh seed is a major factor in germination success.

-Nathan-