The report concerning the Palm - Washingtonia filifera - of Moapa - in SIX parts. [plus photos and bibliography]
'Washingtonia filifera - It's history in Nevada revisited'
By: Spencer, W - December - 1995 ©1995-2011


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Part 5 - Plant Comparisons, Climate & Summary

Plant and Climate comparisons
between recognized Native groves of W. filifera
and the Palm groves of Moapa
& Final Summation

One of the methods used by researchers to validate the possible native presence of certain plants is to compare plant communities of the subject plant with other known communities which support similar biota.

Brown, Carmony, Lowe and Turner in their definitive article (Arizona Academy of Science Vol. 11 Number 1 Feb. 1976) "A Second Locality for Native W. filifera In Arizona determined that populations of Washingtonia filifera at or around Castle Creek Springs in Yavapai county in Arizona were indeed "native" in part by comparisons of the area's riparian and typically riparian communities to those listed by Vogl and McHargue in 1966 in their vegetative descriptions of Palm Oases along the San Andreas Fault.

This is very important to do in the case of the Moapa region because there still appears to exist a great deal of intellectual bias that the area around Moapa is somehow climatically or environmentally different from the areas where Palms are anciently extant to the south.(1)

To conclusively show that not only is this not the case but rather that the area is in fact even more like the Palm communities of California than are the plant communities around Castle Creek and KOFA (where Palms are considered Native) I will first list the Plants which are listed by Vogl and McHargue. Following this, I will show which of those plants are represented at Castle Creek and which of those plants are represented in the area around Moapa for a comparison.

The following plants are listed by Vogl and McHargue as riparian or typically riparian taxa found in the vicinities of Palm Groves along the San Andreas Fault in California.

Acacia greggii

Ambrosia ambrososioides

Atriplex canescens

Baccharis glutinosa, sarothroides

Carex ultra

Celtis pallida

Cercidium floridum

Condalia lycioides

Cynodon dactylon

Haplopappus acradenius

Hymenoclea monogyra

Nicotiana palmeri

Penstemon subulatus

Phragmites communis

Pluchea sericea

Prosopis juliflora, glandulosa, pubescens


Washingtonia filifera

Out of this list of 17 genera and 20 species, Castle Creek's "NATIVE PALM GROVES"exhibit only eight genera and only six of the specific species listed.

Genera are listed with no "species" afterward if only the genus is found:

Acacia greggii

Atriplex ( )

Haplopappus acradenius

Hymenoclea ( )

Phragmites communis

Pluchea sericea

Prosopis juliflora

Washingtonia filifera

Compare this to the following list of Plants found within the ranges of Moapa Valley's Palms:

(Genera found in the vicinity of Palm groves in southern Nevada include the following genera. Species which are not listed by Vogl & McHargue but found in Moapa are in Parentheses:)

Acacia greggii

Ambrosia (eriocentra)

Atriplex canescens

Baccharis blutinosa

Carex (occidentalis, subfuscia )

Celtis (reticulata)

Cynodon dactylon

Haplopappus acradenius

Hymenoclea (salsola)

Nicotiana (glauca, attenulata, triginofila*)(2)

Phragmites communis

Pluchea sericea

Prosopis glandulosa, pubescens & juliflora- (the last by Bradley & Deacon 1965:26-28)

Washingtonia filifera

As you can see, 14 out of 17 genera are found in the Lake Mead Region.(3)

As far as species go, the area exhibits at least 11 of those which are listed by Vogl and McHargue. This is a greater percentage by far than that given by the research of Brown, Carmony, Lowe and Turner for areas with provably Native Palms in Arizona's Castle Creek.

The above discussion amply establishes that as far as comparisons of riparian or typically riparian plants associated with Palms in Southern Nevada are concerned, the possibility that these Palms are indigenous to the region can neither reasonably nor effectively be discounted due to any paucity of common or shared flora when compared to other provably indigenous Palm communities. (Otherwise if Washingtonia filifera is shown to be indigenous to Southern Nevada, which it surely must be, then it could equally be said that communities to the south are deficient of certain taxa such as: Gutierrizia spp. Hymenoclea salsola, Salazoria mexicana and Chilopsis linearis all of which occur near Moapa but apparently not in Palm Springs as of Vogl and McHargue's writings.) I am certain this list could be expanded. However, there seems little point in doing so.

Clearly then, no notion is implied here that all biota found in context with a specific plant are necessarily obligate to all the communities of the subject plant at all locations. Such an idea would seem unreasonable. Comparisons are simply tools for observation. Certainly one could never infer that occurrences of specific plants are unlikely in certain regions simply due to otherwise explainable paucity of often related taxa extant at the compared loci. If other favorable factors are present and the subject plant is not clearly out of its possible indigenous range, then barring any evidence to the contrary, it should be regarded with the native flora until more conclusively shown otherwise.

Continuing the Plant comparisons however, I will now compare other plants (which occur in the Moapa Region) to plants specifically used by Cahuilla of the Native Palm Groves there. A favorable comparison or high degree of recurring instances of typically Ethnographically related flora in such a context could serve the following;

a) to show climate variables for the specific plants are equally favored for such biota in both regions,

b) to show reasonable cause exists for the subject plant to occur in the specified region.

c) to underscore Ethnobotanical similarities which may have existed between groups of Palm using Aborigines.

To begin this discussion, I will turn our attention to the exhibits of the Palm Springs Desert Museum. Listed here are a number of plants which were apparently all used by the Native Americans of that region. Although I have not inquired into whether most of these plants were used historically or otherwise by the Moapa Paiute, I have proceeded here in the following fashion: If the plant is shown to exist in the Moapa region it is very likely the Moapa did use it and they very well may have used it in similar ways. A "yes" next to the listed taxa signifies that this particular plant is also found in the Lake Mead Region of Southern Nevada. A species name in parentheses, (as before), indicates that this is the particular species of this plant known to the Lake Mead Region. This is used only if there is sufficient similarity between different species to facilitate shared or similar cross-cultural uses of a plant. When possible a traditional use of the plant and ethnic group is noted. The notation of an ethnic group does in no way preclude the likelihood that the plant was used by groups where ever it was found, only that this plant has specifically been known to be used in the way mentioned by that particular ethnic group.

Taxa exhibited at Palm Springs Museum Is the Taxa found in vicinity of Moapa?

Dalea (fremontii) -indigo bush Yes

Chupa Rosa or Beloperone Californica No

Salvia Columbariae -chia Yes used for food

Encelia farinosa -brittle brush Yes (Seri) used sap for glue

Geraea Canescens -desert sunflower Yes

Eriogum inflatum -desert trumpet Yes(4) used as greens, seed for flour, herb

Jimson datura -jimson weed Yes ritual hallucinogen

Isomeris arborea - bladderpod No

Salvia apiana No, (mojavensis) Yes (Cahuilla) ate seeds

Jojoba No

Yucca Yes used for food, soap, fiber, liquor

Mormon tea Yes tea, medicinal, other

Creosote bush Yes medicinal, rituals

Juncas Yes baskets Cahuilla, Moapa

Sumac Yes baskets Cahuilla, Moapa

Coyote melon Yes

Mesquite Yes flour cake, drinks, dessert

Pinyon Yes flour, etc

Castilleja chromosa -Indian paintbrush Yes nectar from flowers

Palafoxia Linearis -Spanish needle No

Calochortus kennedyi -Mariposa lily Yes bulbs roasted

Escholtzia parishi No (glyptosperma & minutiflora)Yes pollen facial cosmetic, herbal, greens

Nicotiana trigonophylla -desert tobacco Yes smoked

Camissonia claviformis -browneyed primrose Yes Tohono O'otam & Cahuilla ate leaves also the white lined sphinx moth found with plant eaten

Pluchea sericea -arroweed Yes used with palms for huts, arrows

Mistletoe Yes medicinal, other

Ironwood tree No

Washingtonia filifera -Desert Fan Palm, Yes -Moapa, Cahuilla, Tohono O'otam & Pima used for food, baskets, shelter, fire tools, etc. All these groups are part of the Uto Aztecan or Shoshone based linguistic family and cultures.

Conclusions regarding Plant communities:

The foregoing discussion argues conclusively that the riparian communities extant with the wild Washingtonia filifera groves in the Moapa region follow an unmistakably acceptable pattern echoed in all the native groves throughout the plant's indigenous range. The remaining plant comparisons offered by the Palm Springs Desert Museum's exhibits reiterate and strengthen this argument enormously. Twenty three out of Twenty Eight plants listed by the Palm Springs Desert Museum as having been important to the Native Americans of that immediate area are found near the groves and within the traditional lands of the Moapa Paiute of Southern Nevada. This is a profound and unmistakably important observation!!!

I believe it would be an understatement to say that the Moapa's food and medicinal resources were clearly almost identical to those of the Cahuilla. There is the possible exception of acorns which is not even mentioned here since that important Cahuilla food came from an entirely different biotic community than found in the Palm Springs area. Oaks were furthermore not within range of the Moapa to my knowledge ...although I could be mistaken about this.

In conclusion it is clear that the most important plant communities which made up the environment of the Cahuilla also made up the environment of the Moapa.

With this in mind it almost seems redundant to write a section regarding climate. The former notions of those who classed this area of Nevada with higher elevations and other climate zones need to be revised. It is beyond the scope of this effort to attempt to convince certain people of the obvious. Perhaps those who still doubt should become more well acquainted with the tolerances of this particular palm tree. For not only is the Moapa area well within the tolerances of this plant in regard to climate the plant additionally thrives in areas quite a bit higher in elevation and somewhat colder in winter. Most of the remaining Mojave desert including Twenty nine Palms in California are colder and higher than the Moapa region yet Twenty nine palms is the location for a native grove of Palms which figures in local Aboriginal legend.

However just to reiterate these points I include this section of climate information for those interested in scrutinizing this more closely.

Climate in Southern Nevada's Moapa region.

(for once Las Vegas is not included)

As a rule, Overton winter temperatures are from 2 to 8 degrees warmer (Fahrenheit) than Las Vegas on a given day. Furthermore, although it may seem odd Logandale(5) (only a few miles from Overton) happens to be in a micro- climatic "cold sink." Unfortunately, temperature data has been collected there for many years even though my research and other climate data shows that it misrepresents the entire area by as much as 12 degrees Fahrenheit. According to observations of freeze data for the Lake Mead area (spanning more than ten years) Logandale experienced an average of three times the number of days below freezing as did Moapa, Overton, Rogers Springs and Stuart's Point. On summer evenings this marked cold sink effect is clearly obvious even to the casual observer, by simply driving through Logandale with the car windows down. (See Table 2)

Comparisons of average frost free days in Moapa area of NV to areas in Sonoran deserts:

Table 2- 'Locale' Comparisons of Average frost free days per year over a ten-year period from 1972-1982
(in descending order)

Yuma 350 days

Overton 349 days

Logandale 310 days

(Below is a twenty-year average for the listed Sonoran communities for an interesting comparison)

Phoenix 302 days

Tucson 242 days

Table 2-A Average minimum temperatures for the same areas

NOTE: all temps are given in Fahrenheit following the standard method used in collecting the data.

Logandale 25.6 F

Overton 32.3 F

Yuma 36. F


While the average number of frost-free days during the indicated period in Overton is comparable to Yuma AZ for the same time period, the Average minimum temperature is lowerby about 4 degrees. This suggests that while sub-freezing temps are equally as

infrequent in Overton as in Yuma they tend to be lower.(6) (Also longer in duration.)

Also once again Logandale is a great exception and consistently shows far lower freezing temperatures than any of the surrounding areas. Just for example a comparison of the three coldest days for the ten-year period referenced in the table:

Jan 1973 Logandale's lowest low was 17 deg F

Jan 1974 Logandale's lowest low was 15 deg F and in

Jan 1979 Logandale's lowest low was 15 deg F

For the exact SAME periods 11 miles away for Overton

Jan 1973 Overton's lowest low was 25 deg F (a full 8 degrees higher)

Jan 1974 Overton's lowest low was 22 deg F (a full 7 degrees higher) and in

Jan 1979 Overton's lowest low was 27 deg F.(a full 12 degrees higher)

OBSERVATIONS: In 10 years the author noted that for three separate data collection points: Overton, Echo station, and Stuart's Point, there was NO YEAR in which more than one month experienced temperatures lower than 27 degrees F. and only four days in ten years experienced temperatures below 25 degrees F. The coldest temperature on record for all three stations in ten years was 22 degrees F in Jan 1974 (however only 2 days were recorded for the entire year as being 25 degrees F. or below). For the entire year of 1974 these three locations had only a total of 14 days which show temperatures 32 or below and the lowest of those remaining 12 days (excluding the two days of 25 deg or lower) was only 31 degrees.

The author's observations indicate that subfreezing temps also tend to be longer in duration in Overton than in Yuma (which is as expected). The duration of freezes is probably the most important climatic factor between the two areas. No attempt was made to compare that type of data. Casual frequent trips to Yuma convince the author that the "highs" during the winter days also tend to be much more mild. While few of the "frosts" in Yuma are threatening. Remember, even if the low in Overton is 25 deg. and the duration is 10 hours while the low in Yuma is 32 deg. for five minutes....both locales wind up being classed as having experienced frost in that 24 hour period. This of course tends to offset the figures so this must be duly taken into account.

Still the data supports the idea that the climate around this very Northerly part of the Mojave is indeed far more tolerable to the Desert Fan Palm than has repeatedly been suggested. Note that a similar climatic bias misplaced the type locality of this plant for 107 years!(7)

Other Climate remarks:

A statement made by James Cornett mentioned earlier was that the Mojave Desert is "a region too cold for the genus today." I would like to comment on this idea for a moment to show why I believe this to be a provably unfair assertion.

Although at first, in context his statement appears to indicate a reference to some work of Axelrod, other published materials by Cornett(8) indicate that he in fact, ascribes to this somewhat misleading and provably incorrect idea(9).

In direct contradiction to this, Peter J. Mehringer may have made the most definitive arguments regarding the Mojave's climate. In 1963 as part of the Tule Springs archaeological expedition, his research shows that winter cold for the areas Cornett is concerned with, have remained constant for at least 18,000 years. Aridity and precipitation however, have changed dramatically:

"Paleoclimatic evidence for southeastern Nevada demonstrates no significant changes between 7,000 B.P. and the present, on the basis of pollen spectra. . . . Fossil pollen spectra and Neotoma midden analyses, combined with dendrochronology (Fritts 1971), provide a consistent history of paleo-ecological conditions of the area for the past 18,000 years. . . .Using the above -mentioned studies for the period of 18,000 to 8,000 B. P., paleo-climatic conditions can be characterized as follows: There was a slow transition from cooler temperatures and increased precipitation to conditions similar to those of the present. The increase in temperature is considered to be between 5 degrees and 10 degrees, with winter conditions remaining as they were, and summer temperatures increased. This was accompanied by a 40% decline in precipitation at elevations below 2100 meters." NV State Museum Archeological papers # 19 1984 -pp 36-38 (Also see: Southwest Museum Papers #8 April 1933, SW Museum Los Angeles-by M. R. Harrington pages 167-171 for discussion supporting and elaborating on other aspects of all of the above).

It appears from the forgoing (includes Harrington's work) that the only thing that has really changed has been degree of aridity and availability of water in the entire region. This same trend applies to the Colorado Desert and Coastal and Inland California with increases (not decreases) in summer temps only. Although the available fossils are extremely ancient compared to this recent 18,000 year period, there is no real evidence that the area was intolerably colder for palms before that time. It appears that the demise of widespread palms may have been an extremely ancient occurrence but that conditions were at least more favorable as far as moisture is concerned in many parts of the Mojave and beyond as recently as 18,000 years ago.(10)

To reiterate: Since favorable winter climate has existed in prevailing Mojave locations, for as much as 18,000 years, widespread fossil evidence of fan palms suggests that ancient inland oceans or periods of declining availability of moisture -not cold- wiped out these ancient taxa. Knowing the remarkable consistency winter lows have exhibited for this recent 18,000 year period, it would be a mistake to infer that the climate in the Mojave is somehow now too cold for Palms since Palms are now extant wherever water has been developed and wherever humans have brought seed throughout lower elevations in the Mojave and even beyond. If one considers that these same conditions must have also existed for most areas in the Colorado Desert to the south (where no one could legitimately argue it has ever been too cold for this plant), then it becomes an entirely unreasonable assertion to say the Mojave is now or ever has been a region "too cold for palms."

Additionally, in direct contrast to anyone's assertion that the region is too cold for palms, it has been observed by this author (over a period of nearly twenty years) that at least seven distinctly separate palm genera and their species(11) have been thriving throughout the farthest reaches of the Mojave desert. Although these plantings are mostly all adventive W. filifera with origins in the early 1900's, it is the fact that these plantings may be found near the most extreme boundaries of the Mojave in all directions which I am highlighting. In Table A(following) some of these locations are listed. Many must be old since they were large when the author first noted them between 1977 and 1982. From this table, one familiar with the locations can see that they are indeed spread throughout the entire Mojave desert. Communications with people at random throughout the different areas indicate that palms have been in many of the locations for more than sixty years*, in some cases even one hundred+ years** and in Moapa anciently

Table A. - Localities in the Mojave and northward where palms have been observed.

Baker CA* Barstow CA* Boron CA Boulder City NV*

Bunkerville NV* Echo Bay NV Furnace Creek CA* Glendale NV*

Grapevine Spring CA* Henderson NV* Indian Springs NV Jean NV

Katherine's Landing AZ Kelso CA* Kingman AZ Lancaster CA

Las Vegas NV* Littlefield AZ* Logandale NV** Moapa NV

Beaver Dam AZ* Mojave CA Overton NV*** Pahrump NV

Newberry Springs CA* North Edwards CA Twenty-nine Palms CA* Victorville CA

Palmdale CA Pear Blossom CA Rosamond CA Searchlight NV

Shoshone CA* Stateline NV Tecopa CA** (China Ranch) Temple Bar AZ

St. George UT

Notes on Table A:

It should be noted that Grapevine Springs is near the extreme Northwest boundary of the Mojave. Mojave (the town) lies as far toward the Western boundary as one can go. St. George meanwhile extends beyond the Northeastern Borders of the Mojave. Some may class Kingman AZ with the Colorado desert or at least Sonoran although it is actually colder than St. George Utah, Either way Kingman could represent the extreme eastern boundary. Twenty-nine Palms is part of the extreme Southern boundary. Interestingly, Twenty-nine Palms is apparently one of the colder areas of the Mojave desert and this may be due to its' geographical configuration at the bases of higher elevations. Tecopa and Shoshone (far to the north), appear to experience warmer winters than Twenty-nine Palms.

Furthermore areas in Southern Nevada around Moapa and Overton which are about 200 to 300 meters lower in elevation than Las Vegas (and which climate appears to have been repeatedly misrepresented) apparently experience some of the mildest winter weather of the entire Mojave and indeed have more comparable temperatures to much of the Sonoran Desert to the South. Perhaps it should be included or listed as a similar 'sister' desert with

drainage also to the Colorado river rather than to the Great Basin.

Conclusions Regarding Climate:

I n conclusion it should be clear first of all, that not only is Moapa a region where climate is conducive to palms whenever there is sufficient water and other favorable factors, but additionally as far as climate goes, the entire Mojave desert is suitable for growing Palms. The Mojave is, as noted however, somewhat colder in Winter than most of the area around Moapa.

Clearly at least climate is not now, nor has it apparently ever been a limiting factor in the Palm's survival and persistence in the Moapa region of southern Nevada.

End of Part 5 - 'Plant & Climate Comparisons between groves'

-click here for: PART 6 - Report Summary-

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1. "...the Mojave, a region too cold for the genus today < in reference to Palms>..." James W. Cornett. "The Desert Fan Palm-not a Relict" San Bernardino county Museum association quarterly vol xxxvi No. 2 summer 1989, first paragraph. (back to text)

2. Triginofila was used by the Cahuilla and therefore it is reasonable to assume this species was present at groves in California and simply was not mentioned by Vogl & McHargue. (source: Palm Springs Desert Museum ) (back)

3. Actually, if we counted Palo Verde or Cercidium we have 15 out of 17 genera since Palo Verde is found around canyons near the area of the Hoover Dam. I am not counting it however since that is some distance from the Palms themselves. I am also not counting the numerous Cercidium floridum and microphyllum which are becoming common as landscape plants in xeriscapes in Overton and Moapa although I mention it's presence here to show that it is indeed possible to grow the plant in the area. Ironwood, Olneya tesota (also not listed in the above references) has been used to gauge an area's climate characteristics with regard to the safety of growing citrus in Southern California. Ironwood may be found in the landscapes around in Las Vegas which is some 100 to 300 meters higher in elevation than most of the areas around Moapa. Furthermore, I can testify that an Orange tree grew well, produced bumper crops of oranges and even grew taller than a certain house in Logandale for over thirty years which substantiates that citrus even in a "cold-sink" like Logandale not only survives but may in fact do well around the Moapa region. (back)

4. (the type locality may be in near Overton if derived from Fremont's description. Remember however, Fremont never explored the area around Moapa thoroughly except for a very hurried visit which apparently missed much of the area.) (back)

5. Logandale interestingly, was the location where Cornett collected his information about the Winter lows of that area.: James Cornett, [pers. com.] (back)

6. Although Jeanne Clark on page 32 of Nevada State Museum anthropological papers no. 19 states that the area has only 275 frost free days on average I have found absolutely no hard local data to support this vastly conflicting assertion. (Yet this has been repeatedly used as reference.) This incredibly high number of average days per year with temps 32 deg F. or lower amounts to three full months of daily average frost episodes per year. The author lived in the area and collection of frost data was one extremely important pursuit. Much time was spent at the county extension in Overton pouring over frost data, If frost incidence had ever been so high it would have most certainly have been noted. One possibility is that Las Vegas rather than local data was used under the incorrect assumption that it was all the same. Another possibility is that average temps for Barstow or other far colder Mojave locales were used or lumped together with Moapa...all of which are quite different from each other with respect to frost data, elevation and plant communities. The author's observation is that the Moapa valley's bear far more resemblance to Sonoran communities than to other Upper Mojave communities to the south with respect to all aspects of Flora, Fauna, Climatological and elevation considerations. In fact, the author would suggest that the Moapa drainage is actually a very small and isolated portion of the larger Colorado Desert community to the south with only insignificantly cooler winters. . . (Logandale of course being a possible exception to this as noted.) (back)

7. Arizona's Own Palm: Washingtonia filifera - Desert Plants Vol 5, No. 3 1983 -Victor J. Miller -University of Arizona for Boyce Thompson Arboretum. (back)

8. "The ...expansion north suggests ...the climate has warmed to allow this species to invade." -Cornett, James W. 1991 Population Dynamics of the Palm, Washingtonia filifera, and Global Warming. SBCMA Quarterly 39(2) page 46. (back)

9. This author's observation is that a theory of "Global warming" as a contributing factor in a so called"expansion" [sic] of W. filifera northward, fails to consider important and completely observable facts. See author's rebuttal:"W. Filifera, and Global Warming, -A Rebuttal".-unpublished paper -1996. (back)

10. (S.B. Parrish a California Botanist, in 1907 commenting on a specific latitude stated "this is an area of pines not of Palms" leaving the impression that the two plant types were mutually exclusive to habitat . This however is a broad and misleading statement since not all palms are strictly tropical and not all pines are strictly temperate.) (back)

11. Genera: (In general order of descending occurrence.) Washingtonia, Phoenix, Trachycarpus, Chamaerops, Brahea, Syagrus, Sabal and Livistona. (back)

End of Part 5 - 'Plant & Climate Comparisons between groves'

-go to PART 6 - The Report Summary-

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