PALM SOCIETY ARTICLE

Native California Palms

I hate it when that happens. So in defense of my favorite plant family, I of course spend the next 30 minutes educating this ignorant soul as to the native palms of California. This article seeks to give all palm lovers the necessary armaments to defend your favorite plant family during such a subversive attack by your anti-palm foe.

When asked how many palms are native to California, many would respond one; the California Fan Palm (Washingtonia filifera). How wrong they are. In fact, this answer is wrong by a factor of 5. The correct answer would be 5 palms: The California Fan Palm (Washingtonia filifera); The Mexican Fan Palm (Washingtonia robusta); The Blue Hesper Palm (Brahea armata); The San Jose Hesper Palm (Brahea brandegeei), and finally; The Guadelupe Island Fan Palm (Brahea edulis). In fact, if it hadn't been for the last ice age you would probably be looking out at a bunch of naturally occurring Braheas in your own backyard. These palms were native here not long ago (that will really irritate your new native plant buddy). And they are now aggressively retaking their homeland. In Northern California, I have seen Brahea armata naturalizing occasionally while Brahea edulis seems to reliably germinate and live over the dry season wherever the seed may be carried (that's usually not far from the parent since the seeds are generally too large for birds). However, while Washingtonia filifera is fairly aggressive in its natural regeneration locally, Washingtonia robusta seems dead set upon dominating every possible open space of earth in the state. I love palms, but I am a bit fearful of the ultimate fate of the naturalization of W. robusta throughout our state. It really wants to be here and its amazing that it didn't reach upper California on its own historically (another article?). Nonetheless, in 10,000 years, many palms will become naturalized in California to the point where without written historic records, one would think they are truly native here.

First of all and most important, California should not be thought of as everything north of Tiajuana and south of the Oregon border. Baja California is a natural extension of California geographically, geologically climatically, and botanically. Just like Upper California being divided by a spine of mountains east of the Pacific shore with a moister western face and a drier eastern face, Baja exhibits the same geographic features with its north-south oriented divisional mountain ranges. Geologically the two regions are very similar with similar soil types. And because of the cold oceanic current flowing down from the north at such a fast rate, water temperatures are remarkably homogeneous for such a long coastline with as much latitude that it encompasses (the late January water temperature during my last surf trip at the southern tip of Baja was 66 degrees while San Diego's at the same time was 58). This homogeneity of ocean temperature creates a fairly homogeneous coastal climate very similar to San Diego's for much of the 1000 mile long Baja coastline (albeit critically just more tropical enough in the South to allow the coconut to reliably subsist).

Most notably, much of our familiar California Alta flora extends well South into Baja causing a floristic overlap and blending of our familiar Mediterranean temperate flora with the decidedly more subtropical desert flora of Southern Baja. What is a California native and what isn't? That is the question. My response would be to say that anything found naturally within the Californias and their immediate islands are California Natives. Plants tend not to abide by man made artificially drawn boundaries for their natural distributions. This topic is especially timely to me personally since our nursery will be creating an exhibit focusing on Baja and the floristic overlap between Upper and Lower California at the San Francisco Flower and Garden Show ("Livin' Cheap in Baja- Where the California Biota Meets the Tropics", March 15-19). See photos of the exhibit at our web site at GoldenGatePalms.Com (to be posted by mid April).

Familiar Upper Caliornia trees such as Western Sycamore (Platnus racemosa), Incense Cedar (Calocedrus decurrens), Jeffrey Pine (Pinus Jeffreyi), Quaking Aspen (Populus tremuloides), and California Juniper (Juniperus californica) all occur in Baja. Even our beloved Madrone (Arbutus meziesii) grows in Baja in moist canyons at upper and mid elevations. In fact the Madrone is the most latitudinal ranging tree in the world occurring from Baja California to British Columbia (BC. to BC.- try that riddle on your new native plant freak friend at the next cocktail party). This native range is testament to the ecotypic homogeneity of Upper and Lower California. The tree that really is the slam dunk for me is the Oak. Not less than 15 species of Oaks call Baja their home. The tree that dominates my 8 acre Northern California garden, Coast Live Oak (Quercus agrifolia), also finds moist protected canyons in upper Baja its home as well. In fact, even at the southern tip of Baja, where California gets truly tropical with reliably fruiting Mango, Coconut, and Papaya there exist no less than 5 species of Oaks (3 endemic); Most notably, Quercus brandegeei which closely resembles our emblematic Valley Oak (Quercus lobata) excepting its more lustrous, darker green foliage. I was astonished to see Q. brandegeei growing side by side with Brahea brandegeei. Invariably, your new native plant freak pal will exclaim that Oaks and palms just don't mix. Well, you know what to tell him.

Many of our local native perennials and annuals follow the same pattern in their natural distributions both North and South of the border. Plants such as Penstemon, Ceonothus, Arctostaphylos, Coffeeberry, Salvia, Prunus lyonii, Fremontidendron, Matilja Poppy, Sugarbush, Toyon, Lupine, California Poppy, Dudleya, Yucca whipplei . . . etc find their homes on both sides of the border. They don't discriminate. Many of these familiar "native CA" plants can be seen growing side by side and within the same locales as our beloved "native palms".

So some final thoughts to impart to your new best friend native plant freak: 1) Its OK to love these palms too, and you won't be violating any religious zealot native plant beliefs by including them in your native plant gardens; 2) stop badmouthing palms every chance you get, and most importantly; 3) chill out and stop obsessing so much whether a plant is native or not since the native plant freaks themselves are obviously not native and neither are the "native" Indians technically.

Long live the drifting fragments of Pangea and the constantly evolving diversity among them.

This article posted with permission of the author.
 
Originally published in :
The Palm Journal
Issue 184 Summer 2006