Pseudobahia peirsonii
Encyclopedia
Pseudobahia peirsonii is a rare species of flowering plant in the aster family
known by the common names San Joaquin adobe sunburst and Tulare pseudobahia. It is endemic to California
, where it is known from a few mostly small occurrences along the southeastern side of the San Joaquin Valley where it rises into the Sierra Nevada foothills. It grows in grassland and oak woodland habitat. It prefers heavy adobe
clay
soils. The plant became a federally listed threatened of the United States in 1997.
This species is an annual herb growing 20 to 70 centimeters tall. It has a thin coating of woolly hairs. The leaves are up to 6 centimeters long and are generally divided into a few leaflets which are subdivided into lobed segments. The inflorescence
is a solitary flower head
lined with about eight phyllaries
which are fused at the base, making the involucre a rounded cup with pointed lobes. There are about 8 golden ray florets. At the center of the head are yellow disc florets.
The main threat to its remaining populations is destruction of its habitat for residential development. Other threats include grazing
and agriculture
and maintenance of flood control
structures, transmission line
s, and road
s. The heavy presence of competitive exotic plants
in the habitat, including charlock
(Sinapis arvensis), stork's bill
(Erodium cicutarium), and non-native bromes
, is detrimental.
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 San Joaquin adobe sunburst and Tulare pseudobahia. It is endemic to 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 mostly small occurrences along the southeastern side of the San Joaquin Valley where it rises into the Sierra Nevada foothills. It grows in grassland and oak woodland habitat. It prefers heavy adobe
Adobe
Adobe is a natural building material made from sand, clay, water, and some kind of fibrous or organic material , which the builders shape into bricks using frames and dry in the sun. Adobe buildings are similar to cob and mudbrick buildings. Adobe structures are extremely durable, and account for...
clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
soils. The plant became a federally listed threatened of the United States in 1997.
This species is an annual herb growing 20 to 70 centimeters tall. It has a thin coating of woolly hairs. The leaves are up to 6 centimeters long and are generally divided into a few leaflets which are subdivided into lobed segments. 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....
lined with about eight 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 fused at the base, making the involucre a rounded cup with pointed lobes. There are about 8 golden ray florets. At the center of the head are yellow disc florets.
The main threat to its remaining populations is destruction of its habitat for residential development. Other threats include grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
and agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
and maintenance of flood control
Flood control
In communications, flood control is a feature of many communication protocols designed to prevent overwhelming of a destination receiver. Such controls can be implemented either in software or in hardware, and will often request that the message be resent after the receiver has finished...
structures, transmission line
Transmission line
In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...
s, and road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
s. The heavy presence of competitive exotic plants
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
in the habitat, including charlock
Sinapis arvensis
Sinapis arvensis is an annual or winter annual plant of the genus Sinapis, belonging to the family Brassicaceae. It is commonly known as Field mustard, Wild mustard or charlock.-Etymology:...
(Sinapis arvensis), stork's bill
Erodium cicutarium
Erodium cicutarium, also known as Redstem filaree, Common Stork's-bill, is an herbaceous annual, and in warm climates a biennial member of the Geranium Family of flowering plants...
(Erodium cicutarium), and non-native bromes
Bromus
Bromus is a large genus of the grass family . Estimates in the scientific literature of the number of species have ranged from 100 to 400, but plant taxonomists currently recognize around 160–170 species...
, is detrimental.