Xylorhiza cognata
Encyclopedia
Xylorhiza cognata is a rare species of flowering plant in the aster family
known by the common names Mecca aster and Mecca woodyaster. It is endemic to Riverside County, California
, where it is known only from the Mecca Hills
and Indio Hills
of the Sonoran Desert
. It grows in scrubby habitat in dry desert canyons. It is a shrub
with branching stems that may approach 1.5 meters in length. They are hairy and glandular when new and lose their hairs with age. The leaves are lance-shaped to oval with smooth, toothed, or spiny edges. The inflorescence
is a solitary flower head
with up to 30 or more lavender or pale blue ray florets, each of which may measure over 2 centimeters in length. Flowering begins in January. The fruit is an achene
which may be over a centimeter long, including its pappus
of bristles.
Threats to this species include vehicles in its habitat.
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 names Mecca aster and Mecca woodyaster. It is endemic to Riverside County, California
Riverside County, California
Riverside County is a county in the U.S. state of California. One of 58 California counties, it covers in the southern part of the state, and stretches from Orange County to the Colorado River, which forms the state border with Arizona. The county derives its name from the city of Riverside,...
, where it is known only from the Mecca Hills
Mecca Hills
The Mecca Hills are a low mountain range located in Riverside County, California in southern California, USA, east of the Coachella Valley, west of the Chuckwalla Mountains, and south of Interstate 10 in the Colorado Desert. The range lies in an east-west direction...
and Indio Hills
Indio Hills
The Indio Hills are a mountain range in Riverside County, California.The Indio Hills are along the San Andreas Fault, with natural springs supporting a native California Fan Palm - Washingtonia filifera oasis. The Indio Hills Palms State Reserve and Coachella Valley National Wildlife Refuge are...
of the Sonoran Desert
Sonoran Desert
The Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur. It is one of the largest and hottest...
. It grows in scrubby habitat in dry desert canyons. It is a shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
with branching stems that may approach 1.5 meters in length. They are hairy and glandular when new and lose their hairs with age. The leaves are lance-shaped to oval with smooth, toothed, or spiny edges. 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...
is a solitary flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
with up to 30 or more lavender or pale blue ray florets, each of which may measure over 2 centimeters in length. Flowering begins in January. 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...
which may be over a centimeter long, including its 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...
of bristles.
Threats to this species include vehicles in its habitat.