Monday, March 31, 2014

The hardy Palm Trees of Colorado.

Washingtonia sideroclada ssp. argentea

 Palm trees are generally thought of as Tropical plants, restricted to humid, warm winter regions. Obviously, most people are not aware that there are many iron-clad species, such as this small colony that once grew along Monaco Avenue in Denver, a short ways south of Evans. Despite being planted in a rather exposed microclimate, with a deep sandy soil, these throve for many years: I would admire them as I drove by year in year out, their graceful, bending forms and rigidly proud fronds outstretched with an almost military rigidity: what's not to like? Then a day came when I noticed the sign....

Sign of things to come
 It should have worried me that the restaurant where these where originally planted was rarely patronized...the pressures of development on our endemic urban Arecaceae cannot be overestimated. Not too many weeks passed by before I discovered they were now extinct. Surely the rarest Ironclad, silver Arecas in the region (if not the world) have now joined the Dodo and the Liberal Wing of the Republican party in the annals of prehistory. We cannot be too vigilant, nor can we trust in fly-by-night "conservation" organizations like Nature Conservancy and Defenders of Wildlife, who take little interest in these urban ecotypes. They'd just as soon see this planted to junipers!

 Compare this sad sight with the glorious ecosystem that grew here before "progress" progressed! They may have painted it mustard yellow, and try to distract us with those signs--but surely you can see what's missing?
Cocos nucifera ssp. boulevardensis
Possibly always rare, and now extinct in its type locality--this high altitude coconut palm once throve along Colorado Boulevard here in Denver--producing its characteristic clusters of fruit that fortunately never fell on passers by.

We're not sure if the proximity to "Hooters" has any significance....

I admired the lofty crowns of this evergreen palm for many years, until it too fell victim to "progress"...
Cocos Santafeensis
This delightful colony of an apparently sterile form of the genus still persists--possibly responding to the abundant irrigation on the lawn beneath. I hope some of those would be "environmentalists" will make an effort to preserve this thriving colony before it's too late for it as well!

A closer look!
I am somewhat concerned by the way these are growing that they may, in fact, represent a single clone--the bane of our street tree culture nowadays. By propagating so many trees from single germplasm accessions we reduce biodiversity to a single gene pool--and lay our trees open to all manner of disease and pests. I would not be surprised some day if some sort of rust were not to set in simultaneously on all of these.
A single specimen
Here perhaps you can better admire this distinctive variant planted near a rather outlandish stylized stone: The graceful organic form of the palm makes a striking contrast to the angular, metallic and rather unnatural "stone"--true art if I ever did espy it!

A closer look...trying to ignore that "rock"
Aceca variabilis v. grotesquissimus forma Sinorestaurauntorum

 I shall end my little disquisition on the palms of Denver with this--the most colorful of all of them--reduced, alas, but to a single female that is not likely to produce viable seed with no male palms nearby. How sad it is to think that this noble varicolored hardy palm may one day join its brethren in extinction. Fortunately, we have managed to photograph a few of these to prove that the alpine palms of Denver are still hanging on (albeit by their frond-tips): there are a number of others I've spied over the years--perhaps next year this time I can expand this little monograph to capture them before they too succumb to "progress".


  1. Enter on that list of monopodial palms several other pinnately leaved specimens, to wit, one lonely drupless form west of Sheridan Blvd. along Alameda, south side before you reach Home Depot. Another set of handsome rusty colored Cor-ten steel specimens reside 1 block south of the 1261 Art Gallery on Delaware St. The latter set are coupled in summer with large, live banana trees. There used to be several all-green monsters way north on Wadsworth on the NW corner of a rather large, but forgotten to me, intersection. - J. Borland

  2. the palm with the " rock" needs water : The Bill Barnes

  3. Thanks, Jim, for the heads up on those--I hope they'll be in bloom by the time I visit them in a week or so (off to Iowa)...must add them to my "hardy palm atlas". Yes, Bill--I did notice the containerized specimen wasn't as perk as the ones being properly watered.

  4. Excellent post, great photos, and very apropos!


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