Wildflowers along Lion Tail Ridge. *Bidens alba*, commonly known as white beggarticks, shepherd’s needles, or Spanish needles, is a plant species belonging to the family Asteraceae. The specific epithet “alba” means “white.” It is a perennial herb that can reach nearly 2 metres in height. The stems are square with distinct longitudinal ridges. The leaves vary from simple, ternate, to pinnately lobed or pinnately compound; the leaflets are ovate or lanceolate, with the terminal leaflet being larger and having an acute apex and coarsely serrate margins. Flower heads are terminal or axillary, arranged in corymbs. The outer involucral bracts are spatulate and ciliate, while the inner bracts are lanceolate. The ray florets are white, occasionally with a hint of purplish-red along the veins, and the corolla is 1–1.5 cm long. The disc florets are yellow. The achenes are black, featuring 2 or 3 awn-like pappi with retrorse barbs, which easily latch onto people or animals to disperse across distances.
