Robinsonella cordata

[fastfeat]

The Robinsonella cordata at Fullerton Arboretum is really going off this year. Native to high elevations in Mexico and Guatemala, it performs well in coastal SoCal and probably in the Bay Area as well. And like Chiranthodendron pentadactylon (Monkeyhand Tree) from similar climate, it is probably not well-adapted to the heat of Florida.

It makes a small tree to about 30'/10m. Grows rapidly, but is rather weak-wooded. Bloom time is usually early- to mid-spring. Notoriously difficult to propagate, but as of this week, San Marcos Growers has 5s and 15s for sale; ask your local retailer to order if you want one.

[bahia]

Ken,

I really appreciate you posting photos of this tree! I had noticed that this was a new introduction in this year's catalog for San Marcos Growers, and hadn't been able to find any good photos on-line of what this tree looks like as a landscape candidate, nor much information as to where it might be grown or experience growing it. A small picture of flower detail as per SMG's web site doesn't always translate into something that will be showy in a garden. These photos make it look like it can be fabulous! Sounds like it doesn't bloom all that long, and out of bloom not particularly showy as a tree? Is it typically more columnar in habit as the photos would appear to show?

I think I need this tree! I mean, who doesn't need more blue flowering trees in the garden...

Edited March 20, 2011 by bahia

[fastfeat]

Ken,

I really appreciate you posting photos of this tree! I had noticed that this was a new introduction in this year's catalog for San Marcos Growers, and hadn't been able to find any good photos on-line of what this tree looks like as a landscape candidate, nor much information as to where it might be grown or experience growing it. A small picture of flower detail as per SMG's web site doesn't always translate into something that will be showy in a garden. These photos make it look like it can be fabulous! Sounds like it doesn't bloom all that long, and out of bloom not particularly showy as a tree? Is it typically more columnar in habit as the photos would appear to show?

I think I need this tree! I mean, who doesn't need more blue flowering trees in the garden...

Bahia--

To be honest, this is the largest one I've seen, so I can't say for certain that this form is typical. This tree was originally more rounded, but lost a large limb (about 1/3 of the tree) several years back. Since then, it has been more upright.

There was a trunk of a much larger tree at Franchesci Park in Santa Barbara that was about 20"/50cm in diameter at the time the tree rolled over. Alas, I never saw the live tree. There are other trees at The Huntington and LASCA, but I haven't seen these for comparison.

There is a large tree of R. chiangii at LASCA that has a trunk approaching 24" DBH and was probably 35-40'/12-13m tall when I last saw it (a few years ago.)

[Silas_Sancona]

Bumping this thread just for kicks.. and to see if anyone got their hands one.  Experiences / thoughts if growing it atm.

[mnorell]

This tree has some historical lore surrounding it in California horticulture. As Edwin Menninger wrote in his book, Flowering Trees of the World (which everyone with an interest in flowering trees should have, BTW):

"Southern California had a flurry of excitement in 1953 over the first spectacular flowering of twin trees in front of the John W. Harris residence in Los Angeles. The trees, 15 to 20 feet high and as much across, are Robinsonella cordata, with Hibiscus-like flowers--small, bright purple, in dense clusters.
     Through February and March that year, both trees flowered profusely, giving a 'blue cloud' effect. Los Angeles flower lovers were wild when they discovered that no plants were available, and that they would have to wait until nurserymen could grow some. the nurserymen industriously started doing just that, and even sent hurry calls to Guatemala for propagating materials. The flowering lasted about a month in spite of severe drying winds which doubtless shortened the flowering time.
    Dr. Paul C. Standley placed Robinsonella high on the list of the most beautiful Malvaceae. Their white or bright purple flowers are notable for the delicacy of their coloring, in contrast to the gaudiness that characterizes many members of the family.
     'All species of Robinsonella  are well worthy of cultivation,' he wrote, 'in regions of suitable climate, which should be rather cool and fairly moist. The most attractive of local species is R. divergens of Verapaz, Santa Rosa, and Huehuetenango...' "

The Santa Barbara tree in Lower Orpet park was planted after the aforementioned event, in 1958.  I assume that Evans & Reeves Nurseries in Brentwood (West Los Angeles) would have had something to do either with the original introduction (that tree apparently planted sometime in the 1940s at Mr. Harris's house in Los Angeles), and at least some of its subsequent propagation/distribution.

And according to the article in which the entire genus was described and introduced, in no. 487 of Garden and Forest (23 June 1897), R. cordata was first collected by E. W. Nelson near Tamazulapam, Oaxaca; at 6500-7000 ft, on 16 Nov 1894; and by C. G. Pringle on the Sierra de San Felipe, at 7,500 feet in 1895. A look at the climate of that city shows diurnal variations of 25F in summer and almost 40F in winter. And Google street views of the city center at about 7000' (in the municipal park) show large Ficus microcarpa v. nitida, Jacaranda mimosifolia and other plants typical of coastal SoCal. (It is perhaps a little odd that Menninger describes calls to Guatemala for propagation materials, when the tree is described for Oaxaca, unless its range extends farther south.)

If those original collection-elevations are indicative, it makes sense it would thrive all along the California coastal region, and also inland and maybe even the desert where temps don't fall too much below freezing; and hence why Florida would most likely be a no-go. However, one of the described species in Garden and Forest, R. Lindeniana, is apparently a lowland species and might warrant some exploration for warmer climes if one could get ahold of some seed.

If you want to read the entire genus/species introduction, you can find it here: Garden and Forest, no. 487 - Robinsonella.

[JasonD]

Thanks for the great info, Michael. This genus had been a bit of a mystery to me but now I will look through the article to satisfy my curiosity.

One plant that we at the nursery where I work ordered from San Marcos Growers got planted on San Francisco city property a couple of blocks from the nursery and has thrived. Within a few years it reached nearly two stories tall, and has bloomed nicely a few times in the past five years or so. Some years it blooms in fall as well as spring. Some springs it blooms more than once. Rainfall followed by warm weather seems to favor blooming. The tree is right next to a big Fremontodendron and does not get much irrigation, if any. Photos of flowers on this tree taken early in June are attachedIMG_2913.HEIC.

One small specimen planted at the San Francisco Botanical Garden in a cold spot in their Mesoamerican Cloud Forest section has not fared well. The occasional winter frosts retard its growth. I wonder whether it might stand a better chance uphill, where frost would not be a problem.

IMG_2912.HEIC IMG_2911.HEIC IMG_2910.HEIC

[mnorell]

Those are great photos, Jason...and wonderful to know that this super-rare tree, with your help, is finding some modern-day homes, and in public places, too. And also to know that San Marcos is growing it. Without them California would be a much poorer place horticulturally.

Those flowers first reminded me of its cousin Alyogyne but to me what makes the Robinsonella so much more attractive is the light-colored center that gives sort of a neon effect. Very striking. Do you think it is the concrete around it, and more generally the overall UHI effect in the area, that has made it grow and bloom so impressively? 20' or so in its first few years is quite an accomplishment in SF's cool climate! 

That's also very interesting that it seems to be much less seasonal in SF than in Oaxaca (indeed also in Los Angeles), where according to those descriptions blooming apparently is confined to winter. I have noticed in some other plants (Pittosporum undulatum is the first one that comes to mind) very different blooming patterns in Central/Northern California as opposed to SoCal.

It would be nice if Robinsonella could finally get a foothold in California, where a distinctive flowering tree such as this would make a very nice addition, particularly in the Bay Area where lack of sustained heat makes it difficult to get a showy performance out of some of those lowland tropicals.  Now that San Marcos has it in production, perhaps someone needs to call the Chronicle and get a story in the works about this dynamite new tree in San Francisco...

[Jaime]

Wondered how the Robinsonella handles pruning into a more of a canopy shape?