Lessingia germanorum
Encyclopedia
Lessingia germanorum is a rare species of flowering plant in the daisy family
known by the common name San Francisco lessingia. It is endemic to California
, where it is known from four populations in the Presidio of San Francisco
and one occurrence on San Bruno Mountain
south of San Francisco
. It is a state and federally listed endangered species
. The already rare plant is endangered by many processes, including invasive species
, development, sand mining
, off-road vehicles and bulldozer
s, habitat fragmentation
, trampling, and pollution
, as well as stochastic events
.
This is an annual herb producing a decumbent to erect, reddish stem no more than 30 centimeters long. The deeply lobed leaves are up to 3 or 4 centimeters long. Some leaves and new stem parts are coated in woolly fibers. The inflorescence
is a solitary flower head
or cluster of heads at the tip of the stem. The bell-shaped involucre is lined with pointed phyllaries
that curl back as the head matures. The head is discoid, with no ray florets but several tubular golden disc florets with raylike lobes. The plant blooms in July through November. The fruit is an achene
with a whitish pappus
.
This plant grows in beach sand dunes
and scrub and similar sandy habitat. It is native to the tip of the San Francisco Peninsula
, a land mass which is intensely developed and urbanized
. The single population known on San Bruno Mountain near Daly City
was discovered in 1989 and is threatened by the construction of houses in the immediate vicinity. The largest population of the plants is in the dunes at the mouth of Lobos Creek
in the San Francisco Presidio. Habitat in the area is infested with non-native species
such as ice plant (Carpobrotus
sp.), which produces mats of herbage over the sand dunes, stabilizing the sand; the lessingia requires shifting, windblown sand habitat. Introduced tree
s have also altered the habitat of the lessingia. Old Monterey cypress (Cupressus macrocarpa
) and Monterey pine (Pinus radiata) planted many decades ago remain in the Presidio dunes; these native California trees are not native to this particular ecosystem
, and have become 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 name San Francisco lessingia. 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 four populations in the Presidio of San Francisco
Presidio of San Francisco
The Presidio of San Francisco is a park on the northern tip of the San Francisco Peninsula in San Francisco, California, within the Golden Gate National Recreation Area...
and one occurrence on San Bruno Mountain
San Bruno Mountain
San Bruno Mountain in northern San Mateo County, California is the northernmost part of the Santa Cruz Mountains. Most of the mountain lies within the San Bruno Mountain State Park, a unique open-space island in the midst of the San Francisco Peninsula's urbanization. Next to the state park is the...
south of San Francisco
San Francisco, California
San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...
. It is a state and federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. The already rare plant is endangered by many processes, including invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
, development, sand mining
Sand mining
Sand mining is a practice that is becoming an environmental issue as the demand for sand increases in industry and construction. Sand is mined from beaches and inland dunes and dredged from ocean beds and river beds. It is often used in manufacturing as an abrasive, for example, and it is used to...
, off-road vehicles and bulldozer
Bulldozer
A bulldozer is a crawler equipped with a substantial metal plate used to push large quantities of soil, sand, rubble, etc., during construction work and typically equipped at the rear with a claw-like device to loosen densely-compacted materials.Bulldozers can be found on a wide range of sites,...
s, habitat fragmentation
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...
, trampling, and pollution
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
, as well as stochastic events
Stochastic process
In probability theory, a stochastic process , or sometimes random process, is the counterpart to a deterministic process...
.
This is an annual herb producing a decumbent to erect, reddish stem no more than 30 centimeters long. The deeply lobed leaves are up to 3 or 4 centimeters long. Some leaves and new stem parts are coated in woolly fibers. 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....
or cluster of heads at the tip of the stem. The bell-shaped involucre is lined with 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...
that curl back as the head matures. The head is discoid, with no ray florets but several tubular golden disc florets with raylike lobes. The plant blooms in July through November. The fruit is an 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 whitish 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...
.
This plant grows in beach sand dunes
Dune
In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...
and scrub and similar sandy habitat. It is native to the tip of the San Francisco Peninsula
San Francisco Peninsula
The San Francisco Peninsula is a peninsula in the San Francisco Bay Area that separates the San Francisco Bay from the Pacific Ocean. On its northern tip is the City and County of San Francisco. Its southern base is in Santa Clara County, including the cities of Palo Alto, Los Altos, and Mountain...
, a land mass which is intensely developed and urbanized
Urbanization
Urbanization, urbanisation or urban drift is the physical growth of urban areas as a result of global change. The United Nations projected that half of the world's population would live in urban areas at the end of 2008....
. The single population known on San Bruno Mountain near Daly City
Daly City, California
Daly City is the largest city in San Mateo County, California, United States, with a 2010 population of 101,123. Located immediately south of San Francisco, it is named in honor of businessman and landowner John Daly.-History:...
was discovered in 1989 and is threatened by the construction of houses in the immediate vicinity. The largest population of the plants is in the dunes at the mouth of Lobos Creek
Lobos Creek
Lobos Creek is a stream in Presidio of San Francisco in San Francisco, California.-Overview:It runs from runoff in the Presidio and Seacliff areas and underground seepage from springs that form Mountain Lake to the Pacific Ocean marking the division between Baker Beach and China Beach...
in the San Francisco Presidio. Habitat in the area is infested with non-native 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...
such as ice plant (Carpobrotus
Carpobrotus
Carpobrotus is a genus of ground-creeping plants, with succulent leaves and large daisy-like flowers. The name refers to the edible fruits. It comes from the Greek "karpos" and "brota" .There are about 25 species in this genus, having a disperse distribution worldwide...
sp.), which produces mats of herbage over the sand dunes, stabilizing the sand; the lessingia requires shifting, windblown sand habitat. Introduced tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s have also altered the habitat of the lessingia. Old Monterey cypress (Cupressus macrocarpa
Cupressus macrocarpa
Cupressus macrocarpa, commonly known as Monterey Cypress or Macrocarpa, is a species of cypress that is endemic to the Central Coast of California. In the wild, the species is confined to two small populations, near Monterey and Carmel, California. These two small populations represent what was...
) and Monterey pine (Pinus radiata) planted many decades ago remain in the Presidio dunes; these native California trees are not native to this particular ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
, and have become detrimental.