Plants are abundant below 1,800 feet elevation on dry, gravelly or rocky soils, frequently along the shoulders of highways from Nevada throughout western Arizona and southern California to Lower California. Be on the lookout for this small but interesting and beautiful plant.
Common name: DODDER Arizona and Texas deserts. (_Cuscuta indecora_). White. July-August. California desert. (_Cuscuta denticulata_). Pale yellow. July-August. Convolvulus family. Size: Vine-like, covering host plant.
Rootless, leafless, and with pale yellow to brownish stems which twine in vine-like embrace about the host, the parasitic Dodders are immediately noticeable because of their strange appearance.
Frequently the automobile traveler’s attention is arrested by a pale yellowish blotch in the green of the roadside vegetation. Examination shows this to be caused by the matted yellowish stems and the white to pale yellow, fleshy blossoms. These flowers are attractive and often abundant enough to make a showy display.
Dodder is found widespread throughout the United States and is often a serious parasitic pest on crops of economic importance. Desert species are usually found infesting Mesquite, Goldenrod, Aster, Burrobush, Seepwillow, and Arrowweed. Although certain Dodders show a preference in choosing hosts (_C. denticulata_ common on Creosotebush), most of them grow readily upon various plants.
Common Names: JOSHUA-TREE, TREE YUCCA, GIANT JOSHUA California desert. (_Yucca brevifolia_). Green-white. February-April. Lily family. Size: 15 to 35 feet high; spread of 20 feet.
Because the presence of the grotesque Joshua-tree marks, more effectively than any other plant, the limits and extent of the Mohave Desert, this species is worthy of special recognition. This tree Yucca holds, in the Mohave Desert, similar status to the Saguaro in the Sonoran Desert. Strangely enough, in west-central Arizona, the Saguaro and Joshua-tree are found growing together and there the Sonoran and Mohave Deserts overlap.
And, just as in southern Arizona an area has been set aside as Saguaro National Monument to preserve and protect that species, so in southern California we find the Joshua Tree National Monument.
The Joshua-tree is outstanding among the many species of Yucca because of its short leaves growing in dense bunches or clusters, and because the plant has a definite trunk with numerous branches forming a crown. Great forests of these sturdy trees are found in parts of southern California, southern Nevada, southwestern Utah, and northwestern Arizona where rainfall averages 8 to 10 inches per year.