Erigeron maniopotamicus
Encyclopedia
Erigeron maniopotamicus is a rare species of flowering plant in the aster family
known by the common name Mad River fleabane. It is endemic to northern California
, where it is known from six occurrences in three disjunct
locations in Humboldt
and Trinity Counties
. It grows in open areas in forest, woodland, and meadow habitat along the path of the Mad River
, generally in barren areas without much plant cover. The soils are rocky and tan in color and occur near areas of serpentine soil
s, but the plant does not occur on the serpentine. The species was described to science in 2004 from a type specimen collected on Board Camp Mountain in Humboldt County. The authors named the plant after the Mad River, purposely choosing a Latin name
that interprets the word "mad" as "crazy", rather than "angry", because they liked the sound of it.
This is a perennial herb growing from a taproot
and caudex
unit. The stem is up to 27 centimeters tall and has a coating of rough hairs. The leaves are hairy, lance-shaped, and up to 10 centimeters long by 1.4 wide. The stem and leaves are green or purple-tinged. The inflorescence
is a single flower head
or a cluster of up to 4 heads. Each head has a lining of pointed phyllaries
which are green with orange midnerves. It contains up to 33 white, pinkish, or purple ray florets each about a centimeter long.
Potential threats to the species include grazing
of cattle
, logging
, and activity related to the logging industry including construction and maintenance of roads and dumping.
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 Mad River fleabane. It is endemic to 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...
, where it is known from six occurrences in three disjunct
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
locations in Humboldt
Humboldt County, California
Humboldt County is a county in the U.S. state of California, located on the far North Coast 200 miles north of San Francisco. According to 2010 Census Data, the county’s population was 134,623...
and Trinity Counties
Trinity County, California
Trinity County is a large, rugged and mountainous, heavily forested county located in the northwestern portion of the U.S. state of California, along the Trinity River and within the Salmon/Klamath Mountains. It covers an area of over two million acres , and as of the 2010 census its population...
. It grows in open areas in forest, woodland, and meadow habitat along the path of the Mad River
Mad River (California)
The Mad River is a river in upper Northern California. It flows for in a roughly northwest direction through Trinity County and then Humboldt County, draining a watershed into the Pacific Ocean north of the college town of Arcata near Arcata-Eureka Airport in McKinleyville...
, generally in barren areas without much plant cover. The soils are rocky and tan in color and occur near areas of 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, but the plant does not occur on the serpentine. The species was described to science in 2004 from a type specimen collected on Board Camp Mountain in Humboldt County. The authors named the plant after the Mad River, purposely choosing a Latin name
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
that interprets the word "mad" as "crazy", rather than "angry", because they liked the sound of it.
This is a perennial herb growing from a taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
and 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...
unit. The stem is up to 27 centimeters tall and has a coating of rough hairs. The leaves are hairy, lance-shaped, and up to 10 centimeters long by 1.4 wide. The stem and leaves are green or purple-tinged. 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 single flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
or a cluster of up to 4 heads. Each head has a lining of pointed 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...
which are green with orange midnerves. It contains up to 33 white, pinkish, or purple ray florets each about a centimeter long.
Potential threats to the species include grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
of cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
, logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
, and activity related to the logging industry including construction and maintenance of roads and dumping.