Washingtonia Robusta Naturalized/Invasive in So Cal?

[SCVpalmenthusiast]

I have often wondered why the robusta isn’t considered native to California. I know its native to Baja California, which would have been California if it still belonged to Mexico. I went on a short walk through my paseos to find what appears to be Washingtonia robustas (maybe hybrids with filiferas) everywhere. It appears they have naturalized and are becoming invasive. Every few yards there’s new sprouts. Thoughts? 
 

 

[Silas_Sancona]

2 hours ago, SCVpalmenthusiast said:

I have often wondered why the robusta isn’t considered native to California. I know its native to Baja California, which would have been California if it still belonged to Mexico. I went on a short walk through my paseos to find what appears to be Washingtonia robustas (maybe hybrids with filiferas) everywhere. It appears they have naturalized and are becoming invasive. Every few yards there’s new sprouts. Thoughts? 
 

 

Somewhere around here, you'll find the loonngg thread regarding this discussion with lots of info to digest.. 

Regarding This,  Only organism that acknowledges state / international " Borders " are a certain group of humans..  Rest of the living world,  inc. most humans,  does not. 

Oceans, and limits to climate related adaptations are the only barriers that limit what lives / grows where.. 

Another angle to this story is that, ..in another recent thread,  this one here.. 

  Washingtonia species were recently lumped together, so..  

What you ..and everyone else.. in CA and other warm -enough parts of the west..  are seeing when you see robusta, or hybrids,  or pure filifera  sprouting ..everywhere.. is that particular form of the species expanding it's range, helped in large part by humans bringing it into cultivation.. 

Other parts of the U.S. are close enough that robusta would spread afar on it's own over time.. 


The true invasive?,   the tree saplings in your first shot..  Unless they are CA Walnuts,  most likely,  they are Chinese Pistache,  ..or possibly Tree of Heaven < though the leaflets don't look right for that menace, imo > 

..Note the first part of the common name/ epithet portion of the scientific name < chinensis >..  Is a reflection of where they originated, though some newer cultivars are hybrids w/ other sps from other parts of the old world.   Plants brought here from there / other parts of Asia,  ..or Europe, Africa, and / or AUS.  generally don't have the " checks and balances " organisms around that keep them under control in their respective areas when released into cultivation in the US.. Thus, they can spread and negatively alter New World ecosystems. 

The reverse often occurs when plants introduced from the Americas escapes cultivation in x or y place in the old world. 

Excluding island regions like Cuba, Hawaii, or Puerto Rico,  plenty of checks and balances around that evolved alongside Washingtonia - whatever   to keep them in line, no matter where they're grown in the Americas. 





 

[SCVpalmenthusiast]

3 hours ago, Silas_Sancona said:

Somewhere around here, you'll find the loonngg thread regarding this discussion with lots of info to digest.. 

Regarding This,  Only organism that acknowledges state / international " Borders " are a certain group of humans..  Rest of the living world,  inc. most humans,  does not. 

Oceans, and limits to climate related adaptations are the only barriers that limit what lives / grows where.. 

Another angle to this story is that, ..in another recent thread,  this one here.. 

  Washingtonia species were recently lumped together, so..  

What you ..and everyone else.. in CA and other warm -enough parts of the west..  are seeing when you see robusta, or hybrids,  or pure filifera  sprouting ..everywhere.. is that particular form of the species expanding it's range, helped in large part by humans bringing it into cultivation.. 

Other parts of the U.S. are close enough that robusta would spread afar on it's own over time.. 


The true invasive?,   the tree saplings in your first shot..  Unless they are CA Walnuts,  most likely,  they are Chinese Pistache,  ..or possibly Tree of Heaven < though the leaflets don't look right for that menace, imo > 

..Note the first part of the common name/ epithet portion of the scientific name < chinensis >..  Is a reflection of where they originated, though some newer cultivars are hybrids w/ other sps from other parts of the old world.   Plants brought here from there / other parts of Asia,  ..or Europe, Africa, and / or AUS.  generally don't have the " checks and balances " organisms around that keep them under control in their respective areas when released into cultivation in the US.. Thus, they can spread and negatively alter New World ecosystems. 

The reverse often occurs when plants introduced from the Americas escapes cultivation in x or y place in the old world. 

Excluding island regions like Cuba, Hawaii, or Puerto Rico,  plenty of checks and balances around that evolved alongside Washingtonia - whatever   to keep them in line, no matter where they're grown in the Americas. 





 

Interesting, so now washingtonia filifera includes both robusta and filifera? 

I guess its kind of an oxymoron to be native and invasive. 

So if they’re officially lumped together that means two palms have become native to California. 

[Silas_Sancona]

26 minutes ago, SCVpalmenthusiast said:

Interesting, so now washingtonia filifera includes both robusta and filifera? 

I guess its kind of an oxymoron to be native and invasive. 

So if they’re officially lumped together that means two palms have become native to California. 

To a degree, yes..

More technically,  robusta falls just outside the CA Floristic Province.. 

 That said,   they've been native to this part of North America  ..which includes CA...   for much longer than any of it had names..   

Can't remember if the genus was present on mainland Mexico before Baja broke off and began drifting north and west.. 



Homework: 

** Flora recorded within the Green River Fossil Deposits ..in Wyoming.    Note the " tropical " plant Genus recorded there.  Let alone how far north that is from S. Cal. 

** When Palms, Ficus, and an Avocado relative now restricted to Mexico,  grew around the shallow, warm sea that is now the Central Valley..  

Crocodiles, Boa Constrictor, and Iguana roamed CA ..southern part, of the state at least,   around the same time, perhaps a little longer.   Kern Vulture, a now extinct relative of the exotic looking King Vulture got it's name after it's fossilized remains were un earthed ..in Kern County. 

Current assumed range of the King Vulture itself extends no further than Sinaloa, though all current inat sightings / observations have been from much further south in Mexico.