''Enceliopsis argophylla'', commonly known as the silverleaf sunray, photos plus info on ecology and conservation is a

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

n species of flowering plant in the family

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

. Other common names include nakedstem sunray and naked-stemmed daisy. It is native to the

southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacen ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

(

Mohave County Mohave County occupies the northwestern corner of the U.S. state of Arizona, one of 15 counties in the state. As of the 2020 census, its population was 213,267. The county seat is Kingman, and the largest city is Lake Havasu City. It is th ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

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Clark County Clark County may refer to: *Clark County, Arkansas *Clark County, Idaho *Clark County, Illinois *Clark County, Indiana *Clark County, Kansas *Clark County, Kentucky *Clark County, Missouri *Clark County, Nevada, containing Las Vegas *Clark County, ...

), and

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

( Washington County), and can be seen a short distance east of Las Vegas, Nevada. Enceliopsis argophylla 3

Description

''Enceliopsis argophylla'' is a

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

herb up to tall, appearing silvery because of many small hairs pressed against the leaves. Leaf blades are up to long, with wings running along the sides of the petioles. Appearing in April and May, the

flower head A pseudanthium (; : pseudanthia) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers ...

s are yellow, at the ends of long peduncles, each head with as many as 35

ray florets Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

and up to 500 tiny

disc floret Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

s. The

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

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).Sanders, D. L. and C. Clark. 1987. Comparative morphology of the capitulum of ''Enceliopsis''. American Journal of Botany 74: 1072–1086. American botanist

Daniel Cady Eaton Daniel Cady Eaton (September 12, 1834 – June 29, 1895) was an American botanist and author. After studies at the Rensselaer Institute in Troy and Russell's military school in New Haven, he gained his bachelor's degree at Yale College, then w ...

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 Lake Mead is a reservoir formed by the Hoover Dam on the Colorado River in the Southwestern United States. It is located in the states of Nevada and Arizona, east of Las Vegas. It is the largest reservoir in the US in terms of water capacity. L ...

, it grows on stony barren slopes at 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.

References

External links

Nevada Natural Heritage Program
photos, description, ecological information * ttp://www.wildflower.org/plants/result.php?id_plant=ENAR Lady Bird Johnson Wildflower Center, University of Texas* {{Taxonbar, from=Q15585343 argophylla Flora of Arizona Flora of Nevada Flora of Utah Natural history of the Mojave Desert Endemic flora of the United States Plants described in 1871 Taxa named by Aven Nelson Flora without expected TNC conservation status