About Enceliopsis argophylla (D.C.Eaton) A.Nelson
Enceliopsis argophylla, commonly known as silverleaf sunray, is a perennial herb that reaches up to 80 cm (2.6 feet) in height. It has a distinct silvery appearance, caused by numerous small hairs pressed flat against its leaves. Leaf blades can grow up to 10 cm (3.9 inches) long, and have leafy wings running along the edges of their petioles. Its yellow flower heads bloom between April and May, held at the tips of long peduncles. Each flower head can contain up to 35 ray florets and as many as 500 tiny disc florets. The species produces achenes that are strongly flattened, covered in small hairs, and sometimes bear a pappus made of two awns up to 2 mm long, a trait that differs from many of its close relatives. American botanist Daniel Cady Eaton first formally described this species in 1871, under the name Tithonia argophylla. This plant is found in Clark and Mohave Counties, near the artificial reservoir Lake Mead. It grows on stony, barren slopes at altitudes between 1,000 and 1,500 m (3,300 to 4,900 ft). It often grows alongside the rare golden bear-claw poppy, also called Las Vegas bear-poppy (Arctomecon californica). Both species grow in a fragile gypsum crust covering the soil; damage to this crust helps invasive plants spread. The species' habitat is threatened by the presence of the reservoir, as well as damage from off-road recreational vehicle use.
