Jensia yosemitana
Encyclopedia
Jensia yosemitana is a species of flowering plant in the aster family
known by the common name Yosemite tarweed. It is endemic to California
, where it has a scattered distribution across the Sierra Nevada and its foothills. It is an annual herb with a slender stem up to 25 centimeters tall. The hairy to bristly leaves are 1 to 3 centimeters long and located all along the stem. The inflorescence
produces flower heads
on thin, threadlike peduncles
. The head generally has 2 or more yellow ray florets each about 2 millimeters long and yellow disc florets tipped with black anthers. The fruit is an achene
with a bristly or scaly pappus
.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by the common name Yosemite tarweed. It is endemic to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, where it has a scattered distribution across the Sierra Nevada and its foothills. It is an annual herb with a slender stem up to 25 centimeters tall. The hairy to bristly leaves are 1 to 3 centimeters long and located all along the stem. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
produces flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
on thin, threadlike peduncles
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
. The head generally has 2 or more yellow ray florets each about 2 millimeters long and yellow disc florets tipped with black anthers. The fruit is an achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
with a bristly or scaly pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
.