Packera ganderi
Encyclopedia
Packera ganderi is a rare species of flowering plant in the aster family
known by the common name Gander's ragwort. It is endemic to southern California
, where it is known from a few occurrences in San Diego
and Riverside Counties
.
There are an estimated 4000 plants in existence, but this number varies year to year because the plant becomes more abundant after its habitat burns in wildfire
s.
It is a native of the fire-prone California chaparral
plant community, where it grows in gabbro
rock outcrops.
It is a perennial herb producing a single erect stem which grows to a maximum height of 50 to 80 centimeters. It is mostly hairy and green, but may have some fuzzy areas and a purple tinge. The leaves have rounded or oval blades with toothed edges or shallow lobes. The blades are often thick and somewhat tough, measuring a few centimeters long and borne on petioles
longer than themselves. Leaves occurring farther up the stem are smaller and most lack petioles. The inflorescence
contains up to 6 or 8 flower heads
, each lined with green-tipped, yellow-edged phyllaries
. The head contains many golden yellow disc florets and several orange ray florets each about a centimeter long.
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 Gander's ragwort. It is endemic to southern 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 is known from a few occurrences in San Diego
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...
and Riverside Counties
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,...
.
There are an estimated 4000 plants in existence, but this number varies year to year because the plant becomes more abundant after its habitat burns in wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
s.
It is a native of the fire-prone California chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
plant community, where it grows in gabbro
Gabbro
Gabbro refers to a large group of dark, coarse-grained, intrusive mafic igneous rocks chemically equivalent to basalt. The rocks are plutonic, formed when molten magma is trapped beneath the Earth's surface and cools into a crystalline mass....
rock outcrops.
It is a perennial herb producing a single erect stem which grows to a maximum height of 50 to 80 centimeters. It is mostly hairy and green, but may have some fuzzy areas and a purple tinge. The leaves have rounded or oval blades with toothed edges or shallow lobes. The blades are often thick and somewhat tough, measuring a few centimeters long and borne on petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
longer than themselves. Leaves occurring farther up the stem are smaller and most lack petioles. 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...
contains up to 6 or 8 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 lined with green-tipped, yellow-edged 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 contains many golden yellow disc florets and several orange ray florets each about a centimeter long.
External links
- Jepson Manual Treatment
- USDA Plants Profile
- Flora of North America
- California Native Plant Society Rare Plant Profile
- Photo gallery
Further reading
- Barkley, T. M. and R. M. Beauchamp. (1974). A new Senecio (Compositae) from California. Brittonia 26:2 106-8.