Desert Fan Palm Washingtonia filifera (Lindl.) H.Wendl. Arecaceae Species description Desert fan palm is a native evergreen monocot with a columnar trunk, and the crown is a rosette of large leaves. The immense, fan-shaped leaves are 3-4 feet long and 6-7 feet wide, dividing about halfway up into 50-70 pointed, thready segments. Each year the leaves die, and the upper trunk may be covered in a petticoat of hanging dead leaves. The outer trunk tissue consists of a thick, bark-like rind. The inflorescense is a thick spike or spadix. The fruit occurs in massive clusters; each is a relatively small black-red drupe containing a single large seed. Palm roots may be shallow to deep, following the depth of the water table. Palms usually grow near seeps and springs. Flowering occurs in May and June. The desert palm fruits ripen in September, and the seeds ripen and drop from November to January. Desert fan palms can grow 30-60 feet tall and live for 150-200 years. The palms can withstand brief periods of freezing temperatures. Natural and cultural history Desert fan palms grow naturally in and around seeps, springs, and humid canyons in the southern Mojave Desert down to the central Baja California peninsula. There are a few areas where they grow native in Arizona, in La Paz and Yavapai Counties. Desert fan palms are found near seeps, springs, and streams in their natural environment, below 3,500 feet in elevation. The palms also occur in canyons where water is channeled from nearby mountains, in alluvial fan edges where groundwater is trapped, and where water percolates through rock fractures. They are the keystone species of fan palm oasis communities. Desert fan palm oases are important archaeological sites because they were often selected as locations for villages, or used by migratory peoples of the lower Mojave Desert and Baja California peninsula of Mexico. These oases provided sources of water, food, and shade for early peoples. The native peoples used the vegetative buds, flowers, and fruits of the palms as food. The small fruits were eaten fresh or dried, or dried and made into meal. They also used the leaves for thatching and made sandals, clothing, and baskets from the leaf fibers. The leaf petioles were used to carve spoons and even bows. The palm wood could be used for kindling. Planting considerations and propagation techniques Soils in natural desert fan palm oases are generally undeveloped and low in organic matter. Most soils supporting desert fan palms are high in pH. Desert fan palms are moderately shade tolerant when young and become intolerant with age. Desert fan palms are primarily insect pollinated, but self-pollination can occur. Desert fan palms are easily grown from seed. The seed is abundant; it stores and germinates well, and seedlings transplant easily. Seeds may be sown as soon as they fall from the palm. Pre-soaking for 24 hours in warm water may speed up germination, especially of stored seed. When seedlings are large enough to handle, place them 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. Plants will do best with some protection for the first two years. Water needs Fan palms naturally grow around desert springs and oases and need supplemental irrigation in urban settings. They can survive during extended dry periods. Care The dead leaves should be pruned each year to reduce the fire hazard. Harvesting and processing Desert fan palm fruits are very small and hard, but the thin flesh is sweet and resembles dates in texture and flavor. The fruit may be eaten raw, cooked or dried. The fruits can also be made into jellies and drinks or dried and ground into a meal. The palm seeds can be ground up with the dried fruit and made into porridge or used in bread. The young leaf bases may also be eaten raw or cooked. References and resources California Rare Fruit Growers (CRFG). 1998. Edible Hardy Palm Fruits. https://www.crfg.org/pubs/ff/edible- palms.html Hogan, M. 2009. Washingtonia filifera. iGoTerra: http://www.igoterra.com/artspec_information.asp?thingid=90942 Howard, Janet L. 1992. Washingtonia filifera. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). http://www.fs.fed.us/database/feis/. Plants for a Future (PFAF). n.d. Washingtonia filifera - (Linden. ex André.)H.Wendl. http://www.pfaf.org/user/Plant.aspx?LatinName=Washingtonia+filifera 2 .