Published on December 12, 2007
Desert Cacti and the Joshua TreeBy Jenny Griffes: Desert Cacti and the Joshua Tree By Jenny Griffes General Information: General Information Native to America Only 1 or 2 fossils have been found. The oldest dates back 50 million years ago in Utah (similar to a Prickly Pear) Probably grew in tropical climate until about 65 million years ago when CA changed from year-round rainfall to dry summers and wet winters Adapted to dryness when desert began to form as Sierra Nevadas rose and blocked rainfall Grow on rocky hillsides, alluvial fans, barren washes and nestled in rock crevasses How a cactus survives in the desert: How a cactus survives in the desert It takes advantage of the lightest rainfall by having roots close to the surface When it rains, water is quickly collected by roots and stored in thick, expandable stems for long summer droughts. The “fleshy” stems are pleated like an accordion and shrink as moisture is used up. The stems also channel water to the roots during rainfall. During the summer, they continue to photosynthesize, unlike other desert plants, because they have fixed spines instead of leaves. Green stems make food, but lose less water than leaves because of sunken pores and a waxy coating on surface to protect from the heat of the sun. Pores close during the heat of the day and open at night to release a small amount of moisture. Adaptation to Sun: Adaptation to Sun Spines shade stem, keeping them cool Lean to south so that a minimum of surface area is exposed during the drying effect of the midday sun. Due to water-saving adaptations, cacti grow extremely slowly, as little as 1/4 inch per year Due to the slow growth, many young sprouts never reach maturity. Uses of Cacti: Uses of Cacti Important source of food and water for Bighorn Sheep and Antelope Ground Squirrels Cactus Wren and California Thrasher grow in trees. Birds use spines as protection from foxes, coyotes and predatory birds Woodpeckers chop burrows in long arms of Saguaro Cactus Owls, flycatchers and Starlings use abandoned homes in Saguaros as homes Used for food and medicine for Native Americans for thousands of years -Cahuilla Indians Cahuilla Indians use of Cacti: Cahuilla Indians use of Cacti Harvested fruit of the Beavertail Cactus for sweetness Fruit was cooked and seeds were mashed to mush Flesh pads were cut up and broiled and served as greens Barrel Cactus buds were eaten Buckhorn Cholla was used medicinally. Stems were burned, ashes applied to cuts and burns Barrel CactusGenus Ferocactus: Barrel Cactus Genus Ferocactus Cylindrical or barrel shaped Prominent ribs where heavy spines grow Some species have curved central spines, accounting for the name “Fishhook Cactus” Grow on desert washes, gravely slopes and beneath desert canyon walls in Mojave Grow below 4,500 feet Also known as: Pincushion Cactus, Corkseed Cactus, Nipple Cactus, Fishhook Mammillaria, Cabeza de Viejo Uses of Barrel Cactus: Uses of Barrel Cactus Native Americans boiled young flowers to eat like cabbage, and old flowers were mashed into a drink Used as cooking pot--cut off top, scoop out pulp and insert hot stones with the food Spines used as needles, awls and in tattooing Pulp of Barrel and Prickly Pear Cactus is used for candy In emergency, pulp of stem can be chewed for food and water Flowers, Fruit and Spines of Barrel Cactus: Flowers, Fruit and Spines of Barrel Cactus Yellow-green or red flowers on top Blooms from April to June Flowers grow at top of plant - no spines Fruits are fleshy and juicy when mature - not edible Dense clusters of spines grow along ribs Cholla: Cholla More than 20 species of Opuntia genus in North American deserts Cholla are various shrubby cacti with cylindrical stems composed of segmented joints Only cactus with papery sheaths covering spines -Sheaths are bright, colorful and give the cactus a distinctive appearance bloom April to June Appear as ground creepers, shrubs or trees Height ranges from less than 1 foot (Club or Devil Cholla) to 15 feet (Chain Fruit Cholla) Club or Devil Cholla: Club or Devil Cholla Club shaped joints No sheaths on spines Low growing, forming impenetrable, thick mats Spines can be as sharp as daggers 6,000-8,000 feet Sand Cholla: Sand Cholla Grows in a clump from a bristle covered tuber Favors higher elevation dry lake borders and sandy flats Club shaped, cylindrical joints Pink/magenta flowers with yellow-green Fruit: smooth, red, fleshy, barbed 4,500 - 7,000 feet Prickly Pear: Prickly Pear Member of Opuntia genus Flat, fleshy pads that look like large leaves - Used for photosynthesis, water storage and flower production Large spines - modified leaves, growing from tubercles (small wart-like projections on stems) Unique because of clusters of fine, tiny, barbed spines called glochids Found just above clusters of regular spines Yellow or red Detach easily from pads (difficult to see and harder to remove from skin) Fruit of Prickly Pear: Fruit of Prickly Pear Edible and sold under the name “tuna” Branches and pads are cooked and eaten as a vegetable - sold under the name “Nopalito” The Joshua Tree: The Joshua Tree Grows from 2,000-6,000 feet Dry soils, plains, slopes and mesas Grows in groves Largest of Yuccas - spiked leaf evergreen Member of Lily Family 15-40 feet tall Only grows in the Mojave Flowers and Fruit: Flowers and Fruit Bell shaped Yellow-green sepals Many branched clusters Unpleasant odor Bloom in the spring Elliptical green brown fruit Somewhat fleshy Dries and falls soon after maturity Many flat seeds Pollination: Pollination Trees rely on the female Pronuba Moth to pollinate No other animal visiting the blooms transfers pollen Female Yucca Moth has evolved organs to collect and distribute pollen onto flower surface She lays eggs on flowers ovaries, when larvae hatch, they eat the yucca seeds The tree and the moth need each other. Neither could reproduce without the other The moth needs the seeds and the tree needs the pollination Old Joshua Trees can make new trees but not spread, only the moth can carry the seeds Background: Background Mormon pioneers are said to have named this species "Joshua" Tree because it mimicked the Old Testament prophet Joshua waving them, with upraised arms, on toward the promised land.