Erigeron petrophilus
Encyclopedia
Erigeron petrophilus is a species of flowering plant in the daisy family
known by the common names rockloving erigeron. It is native to the mountain ranges of northern California
and far southern Oregon
, where it grows in forest and woodland, often, as its name suggests, in rocky habitat. It is sometimes a member of the serpentine soil
s flora. This is a perennial herb growing many hairy, glandular, spreading stems from a tough, woody caudex
. The narrow, oblong leaves are equal in size and spaced evenly along each stem. The inflorescence
is a cluster of several flower heads
, each just over a centimeter wide and lined with layers of fuzzy, glandular phyllaries
. The heads are discoid, containing many yellow disc florets and no ray florets. The fruit is a small achene
with a pappus
of bristles.
There are three varieties of this species. One, var. sierrensis, the Sierra erigeron or northern Sierra daisy, is limited to the foothills of the northern Sierra Nevada of California. Another, var. viscidulus, the Klamath rock daisy, is found only in the Klamath Mountains
.
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 rockloving erigeron. It is native to the mountain ranges of northern 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...
and far southern Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, where it grows in forest and woodland, often, as its name suggests, in rocky habitat. It is sometimes a member of the serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s flora. This is a perennial herb growing many hairy, glandular, spreading stems from a tough, woody caudex
Caudex
A caudex is a form of stem morphology appearing as a thickened, short, perennial stem that is either underground or near ground level . It may be swollen for the purpose of water storage, especially in xerophytes...
. The narrow, oblong leaves are equal in size and spaced evenly along each 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...
is a cluster of several flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
, each just over a centimeter wide and lined with layers of fuzzy, glandular 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 heads are discoid, containing many yellow disc florets and no ray florets. The fruit is a small 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 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.
There are three varieties of this species. One, var. sierrensis, the Sierra erigeron or northern Sierra daisy, is limited to the foothills of the northern Sierra Nevada of California. Another, var. viscidulus, the Klamath rock daisy, is found only in the Klamath Mountains
Klamath Mountains
The Klamath Mountains, which include the Siskiyou, Marble, Scott, Trinity, Trinity Alps, Salmon, and northern Yolla-Bolly Mountains, are a rugged lightly populated mountain range in northwest California and southwest Oregon in the United States...
.