Quick Stop Palms # 3: odds and ends trees n' things of Tohono Chul Park..

[Silas_Sancona]

Much like Boyce Thompson and the Desert Museum,  Tohono Chul offers the visitor a chance to explore more than just your typical desert flora.  Here one can start their walk among the palms and other arid adapted tropicals in the Nacapule Canyon display , and end up under a nice example of a streamside / Riparian habitat containing both native and regionally native plants on a different side of the garden. In between are various other areas containing a diversity of plants, a few being somewhat of a surprise.

Interesting native ..and a surprise, not so native Conifer(s):

Arizona Cypress Cupressus arizonica ( standard, non- exfoliating < bark > form )


Nearly perfect Alligator Juniper, Juniperus deppeana specimen.. Unmistakable once one notices the one of a kind bark pattern on this tree. filled the air with that classic " hiking in the mountains " scent when standing inside it's canopy.






Whats this?..  Anything Araucaria is almost never seen in the desert, let alone  at this size. I'm sure starting out below, and growing up through native tree canopy helps this tree survive the heat here.





Some of the non- palm subtropical stuff in the Nacapule Canyon Section / other parts of the garden:

Both forms of Rock Fig, Ficus petiolaris.. Occasional frosts / freezes here keep these smaller than some specimens seen around Phoenix.

F. petiolaris var. petiolaris




F. petiolaris var. palmeri


Sonoran Seagrape, Coccoloba goldmanii. Assuming all the garden's specimens are one sex ( though birds could have stripped any fruit bearing female specimens )






Plant for which both the garden and Canyon in Sonora was named for, Nacapule Jasmine, Vallesia baileyana / laciniata ( some sources lump the two species names together )  Pretty sure the form here is the true species ( Hard to see in the picture but leaves are covered by a fine fuzz ) though i have heard plants from different places can vary a bit.  A close relative, Pearlberry ( Vallesia glabra ) typically produces leaves that lack the fuzz / are shinier. Flowers are usually smaller as well, and produced in a different fashion along the stems. Regardless, flowers of both are intensely fragrant.



Southwestern Coral Tree, Erythrina flabelliformis.  Drought and frost keeps many specimens out in the nearby mountains much smaller and scrappier than this and a couple other specimens in the overall garden. This particular specimen would reflect a height / size seen further south in Sonora where cold winter temps don't prune it every so often. 


Down there ( and locally, in some cases ) 15-25ft tall specimens, along with several other dry tropical tree species, contribute to a sort of " Fall color season in the dry tropics " show across the landscape. Unlike trees that drop their leaves in response to cold temperatures / lowering sun angle / daylight hours across temperate parts of the U.S. Trees in Southern Sonora drop their leaves in response to the drier conditions that follow the end of Monsoon Season across Northwestern Mexico.



Coral Vine / Queen's Wreath, Antigonon leptopus.  A cursed weed in some places. To others, it adds valuable late season color in very dry places. Bees, and pretty much every butterfly in the area will find it. As mentioned before, a white flowering version is a bit tamer than the typical form. One of several viney things that pop up in the Dry Tropical Forests during the middle / end of Monsoon Season.




Jatropha vernicosa..  One of the tree - sized Tropical Jatropha species from Baja Sur / Southern Sonora.


Ipomoea arborescens, of the 3  White  flowered, " Tree " Morning Glories in Mexico.  Not sure about the other two but I. arborescens flowers only in winter after leaves have been shed.  Specimen here is one of the largest in the state.



A few Interesting Legumes ..and a couple other surprises..

Slimpod / Wooly Senna, Senna hirsuta var. glaberrima ( sometimes labeled as Senna h. var leptocarpa ) Unlike many of our other native/ regionally native Sennas, this species is perhaps the most " Tropical looking " Sena species in a very arid part of the region. When happy, these can grow 4-6ft tall and wide. Winter deciduous ( dies to the ground ) but hardy to zone 8.




Example of a bigger specimen observed up on Mt. Lemmon, via iNaturalist: https://www.inaturalist.org/observations/48479314

Seeds and a couple rather large Arizona Kidneywood  specimens.  Have yet to see any even half this size in Phoenix ( rare sight as it is )







Arroyo Sweetwood, Myrospermum sousanum bigger and better than the last time i'd seen this specimen.






Last time i'd visited, there were a few unexpected trees planted in a sheltered ( tree canopy ) section of the main courtyard of the garden. At that time, both trees seen on this visit, and a small Tabebuia aurea / caraiba seemed very out of place in an area that can be dusted by snow.  Fast forward a few years and, to my surprise, 2 of the 3 trees are still growing.. Wish the Tabebuia were still growing too.

While there was a sign next to it, did not recognize ( nor remember ) which Cassia species this was.. Do recall it definitely was not native and tropical..


Yea it is skinny and weaving it's way up through the canopy above, but was not expecting to see this tree alive,  and ..relatively happy..  again.   Would be incredible to see these end up hardy enough that they turn up in landscapes in the most ideal spots around Tucson sometime in the future.. Have yet to see a single specimen planted anywhere i have been in the Valley / around Phoenix.

[Silas_Sancona]

Remaining odds n' ends:

Guaiacum angustifolium




Arizona Sycamore, Platanus wrightii.. Fills the air with that same weirdly interesting earthy scent as other Sycamores. Can be seen as far south as Alamos Sonora where it can be found growing along river canyons beside various locally native Ficus, Montezuma Cypress, Psidium sartonianum ( Sonoran Guava ), Handroanthus impetiginosus, and various Legume- type trees whose ranges reach their northern limit from more tropical areas along western Mexico to the south.


Mexican Blue Oak, Quercus oblongifolia, one of two specimens in the garden.  This summer moisture tolerant Quercus species was likely much more widely distributed in wetter times, and is thought to be the great grandmother to Southern California's  Engleman Oak,  which looks very similar.




A few Cycas and Dioon:




Late season Flowers:

Thurber's Cotton, Gossypium thurberi.. Grows as a rather skinny, tree looking shrub and goes deciduous in winter. Before hand,Maple like foliage adds rare splashes of fiery red/ orange fall color tot he landscape in AZ and down in Sonora. Unlike other species of Cotton, seedpods lack the " fluff ". Two additional, similar looking species can occasionally be found for sale in nurseries. Another, San Marcos Hibiscus, Gossypium harknessii, ( Central/ Southern Baja ) is more commonly seen / planted locally.





Whitemouth Dayflower, Commelina erecta.. Somewhat aggressive spreading native in shady moist spots but adds both those bright light blue flowers, and tropical looking foliage to such places.




One of our native Acalypha ( Copperleaf ) species.


Sonoran Spider lily, Hymenocalis sonorensis. Loves moist spots near ( or in ) shallow water.  Flowers fragrant, like other Hymenocalis species.

[Jerry@TreeZoo]

Great photos Silas.  I am amazed how many south Florida natives have relatives  in the SW desert.