''Tetraneuris torreyana'' is a North American species of plants in the sunflower family, known by the common name Torrey's four-nerve daisy. It grows in the western United States, in extreme southern

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

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 ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

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 ...

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

, and

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

. ''Tetraneuris torreyana'' is a perennial herb up to tall. It forms a branching underground

caudex A caudex (: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is most ...

sometimes producing as many as 40 unbranched, above-ground stems. One plant can produce as many as 40 flower heads. Each head has 7–14 yellow ray flowers surrounding 25-150 yellow disc flowers.Flora of North America, ''Tetraneuris torreyana'' (Nuttall) Greene, 1898.
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References

torreyana Flora of the Western United States Endemic flora of the United States Plants described in 1841 Taxa named by Edward Lee Greene Taxa named by Thomas Nuttall {{medicinal-plant-stub