Enceliopsis argophylla explained

Enceliopsis argophylla, commonly known as the silverleaf sunray,[1] is a North American species of flowering plant in the family Asteraceae. Other common names include nakedstem sunray and naked-stemmed daisy. It is native to the southwestern United States: Arizona (Mohave County), Nevada (Clark County), and Utah (Washington County),[2] and can be seen a short distance east of Las Vegas, Nevada.[1]

Description

Enceliopsis argophylla is a perennial herb up to 80cm (30inches) tall, appearing silvery because of many small hairs pressed against the leaves. Leaf blades are up to 10cm (00inches) long, with wings running along the sides of the petioles. Appearing in April and May, the flower heads are yellow, at the ends of long peduncles, each head with as many as 35 ray florets and up to 500 tiny disc florets. The achene is strongly flattened, covered with small hairs, and sometimes with a pappus of 2 awns up to 2 mm long (unlike some of the related species).[3] [4]

Notes and References

  1. Web site: My Chicago Botanical Garden, A Rare Plant Portrait: The Silverleaf Sunray (Enceliopsis argophylla) . 22 June 2015 . 20 February 2013 . Still, Shannon . Jensen, Nick . My Chicago Botanic Garden . Chicago Botanic Garden. photos plus info on ecology and conservation
  2. Web site: County distribution map . Biota of North America Program . 2014 . 22 June 2015 .
  3. Web site: Enceliopsis argophylla (D. C. Eaton) A. Nelson . Flora of North America . 22 June 2015.
  4. Sanders, D. L. and C. Clark. 1987. Comparative morphology of the capitulum of Enceliopsis. American Journal of Botany 74: 1072–1086.
  5. Book: Botany . Eaton, Daniel Cady . Watson, Sereno . 1871 . United States Geological Exploration [sic] of the Fortieth Parallel |volume= 5 |page= 423}}[4]

    American botanist Daniel Cady Eaton described the silverleaf sunray as Tithonia argophylla in 1871.

    Distribution and habitat

    Found in Clark and Mohave Counties in the vicinity of the artificial reservoir Lake Mead, it grows on stony barren slopes at 1000to altitude. It often grows alongside the rare golden bear-claw poppy or Las Vegas bear-poppy Arctomecon californica. Both plants grow in a fragile gypsum crust on the soil, which when damaged facilitates the spread of invasive plants. Its habitat is threatened by the reservoir as well as off-road recreational vehicle use.

    External links

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