Verbesina dissita
Encyclopedia
Verbesina dissita is a rare species of flowering plant in the aster family
known by the common name bigleaf crownbeard. It is native to northern Baja California
in Mexico, where it is known from about 23 occurrences, although some of these may have been extirpated
or are vulnerable to destruction. It is also known from a 3.2-kilometer section of the coastline near Laguna Beach
in southern California
, where it is susceptible to extirpation in a highly developed section of valuable oceanfront land. Other threats include erosion
and competitive introduced species
of plants. This is a federally listed threatened species of the United States.
This is a subshrub
growing 50 centimeters to over a meter in height. The green leaves are oppositely arranged and have oval blades up to 12 centimeters long by 6 wide. They are hairless to roughly hairy and have smooth or slightly toothed edges. The inflorescence
is a cyme of up to 16 sunflower-like flower heads
with deep yellow ray florets each up to 2.5 centimeters long. At the center are up to 100 disc florets with long yellow corollas and dark brown anthers. The fruit is a brown, winged achene
over a centimeter in length including the pappus
at the tip.
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 bigleaf crownbeard. It is native to northern Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
in Mexico, where it is known from about 23 occurrences, although some of these may have been extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
or are vulnerable to destruction. It is also known from a 3.2-kilometer section of the coastline near Laguna Beach
Laguna Beach, California
Laguna Beach is a seaside resort city and artist community located in southern Orange County, California, United States, approximately southwest of the county seat of Santa Ana...
in 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 susceptible to extirpation in a highly developed section of valuable oceanfront land. Other threats include erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
and competitive introduced species
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...
of plants. This is a federally listed threatened species of the United States.
This is a subshrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
growing 50 centimeters to over a meter in height. The green leaves are oppositely arranged and have oval blades up to 12 centimeters long by 6 wide. They are hairless to roughly hairy and have smooth or slightly toothed edges. 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 cyme of up to 16 sunflower-like flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
with deep yellow ray florets each up to 2.5 centimeters long. At the center are up to 100 disc florets with long yellow corollas and dark brown anthers. The fruit is a brown, winged achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
over a centimeter in length including the 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...
at the tip.