One of the handsomest of desert spring annuals, _Calycoseris_ is common on plains, mesas, and rocky slopes at elevations between 1,200 and 4,000 feet from western Texas to southern Utah, southern California, and south into Mexico. The name Tackstem comes from the presence of numerous tack-shaped glands which protrude from the stems. Taking advantage of the cool, moist weather of winter, the Tackstems produce their beautiful rose, white, or yellow blossoms in early spring, and mature their seeds before the advent of hot, dry weather. YELLOW [Illustration: Brickellia coulteri Brickellia californica] Common Names: BRICKELLBUSH, DESERT BRICKELLIA, (_PACHABA_) Arizona desert: (_Brickellia coulteri_). Yellow-white. September. California desert: (_Brickellia desertorum_). Pale yellow. Midsummer. Texas-New Mexico deserts: (_Brickellia californica_). Yellow-white. July-October. Sunflower family. Size: Small, much-branched perennial shrub, up to 3 feet in height. Intricately branched and brittle-stemmed, this shrub with blossom heads holding from 8 to 18 yellowish flowers is common throughout the Southwest from western Texas and Colorado to Nevada, Sonora and Lower California. It grows among rocks and in rocky locations throughout much of the desert country from 3,000 up to 7,000 feet. YELLOW [Illustration: Zinnia pumila] Common Names: WILD-ZINNIA Arizona and Texas deserts: (_Zinnia pumila_). Pale yellow. April-October. Sunflower family. Size: Low, dense-growing perennials in rounded clumps, 4 to 8 inches high. Closely related to the garden Zinnia, which is a native of Mexico, desert Zinnias are attractive herbs suitable for trial as ornamental border plantings. _Z. pumila_ prefers caliche soils and is found on dry mesas and slopes from Texas westward to southern Arizona and northern Mexico. It is often found blossoming in association with the Paperflower (_Psilostrophe cooperi_) which it superficially resembles. The pale yellow flowers of the Wild-zinnia turn white with age. _Z. pumila_ may be easily recognized by the single heavy rib running the length of each narrow leaf. YELLOW [Illustration: Acacia greggi] Common Names: CATCLAW, CAT’S-CLAW, TEARBLANKET, DEVILSCLAW Arizona, California, and Texas deserts: (_Acacia greggi_). Pale yellow. April-October. Pea family. Size: Up to 20 feet tall. The numerous thorns, short and curved like a cat’s claw, serve readily to identify this common, often abundant, shrub or small tree.