''Jensia yosemitana'' is a 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 ...

known by the common name Yosemite tarweed. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, where it has a scattered distribution across the

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

and its foothills. Some of the populations lie inside

Yosemite National Park Yosemite National Park ( ) is a List of national parks of the United States, national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The p ...

. ''Jensia yosemitana'' is an annual herb with a slender stem up to 25 centimeters (10 inches) tall. The hairy to bristly leaves are 1 to 3 centimeters (0.4-1.2 inches) long and located all along the stem. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

produces

flower heads 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 ...

on thin, threadlike peduncles. The head generally has 2-8 yellow ray florets each about 2 millimeters (0.08 inches) long and 1-7 yellow disc florets with black anthers. The fruit is an

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 ...

with a bristly or scaly pappus.Flora of North America, ''Jensia yosemitana'' (Parry ex A. Gray) B. G. Baldwin. 1999
/ref>

References

External links

United states Department of Agriculture Plants ProfileCalphotos Photo gallery, University of California
Madieae Endemic flora of California Plants described in 1882 Flora without expected TNC conservation status {{Madieae-stub