Machaeranthera juncea
Encyclopedia
Machaeranthera juncea is a species of flowering plant in the aster family
known by the common name rushlike bristleweed. It is native to northern Mexico and it occurs in the United States only as far north as San Diego County, California
. It grows in coastal and inland slopes and canyons. It is a perennial herb growing erect to a meter in height. The linear leaves are mostly located at the base of the plant, each 1 or 2 centimeters long and toothed or cut into bristle-tipped lobes. The inflorescence
bears one or more flower heads
lined with glandular, bristle-tipped phyllaries
. The head has a center of many yellow disc florets and a fringe of 15 to 25 yellow ray florets each about half centimeter long. The fruit is a hairy achene
2 to 3 millimeters long tipped with a 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 rushlike bristleweed. It is native to northern Mexico and it occurs in the United States only as far north as San Diego County, California
San Diego County, California
San Diego County is a large county located in the southwestern corner of the US state of California. Hence, San Diego County is also located in the southwestern corner of the 48 contiguous United States. Its county seat and largest city is San Diego. Its population was about 2,813,835 in the 2000...
. It grows in coastal and inland slopes and canyons. It is a perennial herb growing erect to a meter in height. The linear leaves are mostly located at the base of the plant, each 1 or 2 centimeters long and toothed or cut into bristle-tipped lobes. 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...
bears one or more flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
lined with glandular, bristle-tipped phyllaries
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
. The head has a center of many yellow disc florets and a fringe of 15 to 25 yellow ray florets each about half centimeter long. The fruit is a hairy achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
2 to 3 millimeters long tipped with a 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...
.