Wikipedia states: It is a palm native to the desert oases of Central, southern and southwestern Arizona, southern Nevada, extreme northwest Mexico and the inland deserts of Southern California. This palm grows up to 23 m (exceptionally 30 m) in good growing conditions. It is the only palm native to the contiguous United States west of the Balcones Fault Zone in Texas (except for isolated stands of Sabal minor in the Texas Hill Country [ Clover, E. U., 1937. Vegetational survey of the lower Rio Grande valley, Texas. Madrono 4:41-72 ]. The leaves have a petiole up to 2 m long, bearing a fan of leaflets 1.5-2 m long, with white, thread-like fibers between the segments. When the leaves die they bend downwards and form a skirt around the trunk. The shelter that the skirt creates provides a microhabitat for many invertebrates. Washingtonia filifera can live from 80 to 250 years or more. The genus name honors George Washington, the first President of the United States. Ecology: Fan palms provide a habitat for Bighorn Sheep, Hooded Oriole, Gambel's Quail, Coyotes, and the palm boring beetle Dinapate wrightii (Coleoptera: Bostrichidae), and a rare bat species, Lasiurus xanthinus is especially fond of W. filifera groves. Hooded Orioles rely on the trees for food and places to build nests. Both Hooded Orioles and coyotes play an integral part in seed distribution. Dinapate beetles can be problematic and chew through the trunks of the trees. Eventually a continued infestation of beetles can kill a palm, opening up space for a new palm to grow. Today due to urbanization, palm oases are disappearing. Increased agriculture has lowered ground water supplies which decreases the amount of water available in palm oases. This creates a threat not only to the far western United State's only native palm, but also all the organisms which rely on these trees in order to survive. Fossils of this palm are known to exist as far north as Colorado, Wyoming and Oregon. The palm apparently reached its current form by at least 50 - 70 million years BP. Natural oases environments are mainly restricted historically to the area surrounding warm or hot springs, near the source, or shortly downstream from the source. Grazing animals including deer and cattle and in more ancient times, Giant Sloths and other extinct herbivores, can kill young plants through trampling, or by eating the terminus at the apical meristem, which is the growing portion of the plant. This may have kept these palms restricted to a lesser range than would have been expected if one simply considers the availability of water sources. Typically, the oasis environment found today is one which may have been protected from colder climatic changes over the course of its evolution. Thus this palm is restricted by both water and climate to widely separated relict groves. The trees in these groves show little if any genetic differentiation, which suggests that this species is genetically very stable. Cultivation and uses: The fruit of the fan palm was used by Native Americans. It was eaten raw, cooked, or ground into flour for cakes. The Cahuilla tribe used the leaves to make sandals, thatch roofs, and for making baskets. The fan palm was a valuable resource and the stems were used to make utensils for cooking. The Moapa band of Paiutes as well as other Southern Paiutes have stated memories of grandparents also using this palm's seed, fruit or leaves for various things. It should be noted that The Southern Paiutes are related linguistically and by ancient trade routes to the Cahuilla. It is widely cultivated as an ornamental tree. (It is not as widely cultivated as the Mexican Fan Palm Washingtonia robusta - a close cousin which is grown throughout the lower elevations of Nevada, California, Arizona, Texas, New Mexico and extreme southwestern Utah. W. filifera is one of the hardiest of Coryphoidiae palms, and repeatedly survives dips into the teens and even several inches of snow, making it a favorite of cold-hardy palm enthusiasts. The less hardy cousin W. robusta needs slightly milder winters and may be visibly damaged at 20 degrees Fahrenheit and is also more amenable to humidity making it more favored along the Gulf Coast, in states such as Texas, Louisiana, and Florida, and the Mediterranean region. It is widely grown in interior Texas, as it is sufficiently hardy in such places as San Antonio, Austin, Midland, Odessa, and El Paso. The plants grow best in warm temperate climate with dry winters and wetter summers. Specimens outside of Mediterranean climates do not grow as large, rarely exceeding 15 m. The plants are tolerant of considerable frost and the species is rated as hardy to USDA zone 8; it will survive temperatures of -10 °C with minor damage, and established plants have survived brief periods of temperatures as low as -12 °C but with severe damage to the foliage.

The Plants For A Future Database describes on its website: Washingtonia filifera - (Linden. ex André.)H.Wendl. Desert Fan Palm Author (Linden. ex André.)H.Wendl. Botanical references 71 Family Palmae Genus Washingtonia Synonyms Known Hazards None known Range South-western N. America - S. California, S.W. Arizona, N.W. Mexico. Habitat Often forming extensive groves or small isolated clumps in moist alkaline spots in rocky canyons about seeps, springs and streams below 1500 metres[71, 82, 166]. Edibility Rating 2 (1-5) Medicinal Rating 0 (1-5) Physical Characteristics An evergreen Tree growing to 12m by 12m at a medium rate. It is hardy to zone 9. It is in leaf all year, in flower from July to August, and the seeds ripen from November to January. The flowers are hermaphrodite (have both male and female organs) The plant prefers light (sandy), medium (loamy) and heavy (clay) soils. The plant prefers acid, neutral and basic (alkaline) soils and can grow in very alkaline and saline soils. It cannot grow in the shade. It requires dry or moist soil and can tolerate drought. Habitats Woodland Garden; Sunny Edge; Dappled Shade; South Wall By; West Wall By; Edible Uses Edible Parts: Fruit; Leaves; Seed. Fruit - raw or cooked or dried for later use[2, 46, 161, 177, 257]. It can be made into jellies and drinks or dried and ground into a meal[46, 183]. The seed can be ground up with the dried fruit and then both are eaten as a porridge[246]. The fruit is small and hard[213], but has a thin sweet pulp that tastes somewhat like dates[183, 213]. The ovoid fruit is about 6mm long and 4mm wide[200]. Young central bud - roasted[46, 177, 183]. Harvesting this central bud will kill the tree since it is unable to make side branches[K]. Young leaf bases - raw or cooked[161, 177]. Seed - cooked. It can be ground into a powder and used for making bread or porridge[161, 183]. Medicinal Uses Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally. None known Other Uses Fibre; Musical; Weaving. A fibre from the leaves is used in basket making and for cordage[46, 169]. The whole leaves are woven and used as the side walls and roofs of huts and temporary dwellings[46, 257]. The seeds have been used as the rattle in gourd rattles[257]. Wood - light and soft[82]. It has been used for making cooking implements, spoons etc[257]. Cultivation details Requires a sheltered sunny position in a fertile moist but well-drained soil[188, 231]. Tolerates some salt in the soil[200] and maritime exposure in climates that are warmer than Britain[200]. Plants can tolerate extensive droughts so long as their roots have tapped into underground water supplies[231]. Plants can tolerate light frosts and should succeed outdoors in the mildest parts of Britain[166]. They have been known to tolerate short-lived lows down to about -10°c[231]. This species has an extensive and fleshy but strong root system that can penetrate to a considerable depth in search of water[231]. It generally establishes best when planted out at a young stage. However, older plants are substantially more cold tolerant than juvenile plants[231]. In areas at the limit of their cold tolerance, therefore, it is prudent to grow the plants in containers for some years, giving them winter protection, and only planting them into their permanent positions when sheer size dictates[231]. Palms can also be transplanted even when very large. Although the thick fleshy roots are easily damaged and/or desiccated, new roots are generally freely produced. It is important to stake the plant very firmly to prevent rock, and also to give it plenty of water until re-established - removing many of the leaves can also help[231]. Plants growing in the wild are seen as an indication of underground water[200]. Plants produce a 'skirt' of old dead leaves, this can be a fire hazard and the old leaves are usually removed when being grown in areas liable to forest fires[200]. A fast growing tree, even when young, in its native environment and very tolerant of transplanting despite its deep root system[200]. Propagation Seed - best sown as soon as it is ripe in a greenhouse. Pre-soaking for 24 hours in warm water may speed up germination, especially of stored seed[200]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first two winters. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Give the plants some protection from the cold for at least their first two winters outdoors. Links References [K] Ken Fern Notes from observations, tasting etc at Plants For A Future and on field trips. [2] Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972 ISBN 0-486-20459-6 Lots of entries, quite a lot of information in most entries and references. [46] Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959 An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader. [71] Munz. A California Flora. University of California Press 1959 An excellent flora but no pictures. Not for the casual reader. [82] Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. 1965 ISBN 0-486-20278-X Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. [161] Yanovsky. E. Food Plants of the N. American Indians. Publication no. 237. U.S. Depf of Agriculture. 0 A comprehensive but very terse guide. Not for the casual reader. [166] Taylor. J. The Milder Garden. Dent 1990 A good book on plants that you didn't know could be grown outdoors in Britain. [169] Buchanan. R. A Weavers Garden. 0 Covers all aspects of growing your own clothes, from fibre plants to dyes. [177] Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984 ISBN 3874292169 An excellent book for the dedicated. A comprehensive listing of latin names with a brief list of edible parts. [183] Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990 ISBN 0-9628087-0-9 Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world. [188] Brickell. C. The RHS Gardener's Encyclopedia of Plants and Flowers Dorling Kindersley Publishers Ltd. 1990 ISBN 0-86318-386-7 Excellent range of photographs, some cultivation details but very little information on plant uses. [200] Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992 ISBN 0-333-47494-5 Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed. [213] Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980 ISBN 0-449-90589-6 A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical. [231] McMillan-Browse. P. Palms for Cooler Climates. Trebah Enterprises. 1993 ISBN 0 9521952 0 8 An excellent little booklet on the subject, though it does not mention many plant uses. [246] Radio 4 AM - 1997 A news item on the Radio 4 morning news programme 'AM', 15/10/97. [257] Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998 ISBN 0-88192-453-9 Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.