Water howellia
Encyclopedia
Howellia aquatilis is a small plant in the family Campanulaceae
and is considered to a threatened species since 1994. It is the only species in the monotypic genus Howellia. Thomas Jefferson Howell and Joseph Howell discovered the species in 1878.
, Idaho
, Montana
, and Washington, and it is known historically from Oregon
.
The plant grows in wetland
habitat surrounded by forests, which provide organic material. Associated tree species include Populus trichocarpa
(California poplar), P. tremuloides
(quaking aspen), and Fraxinus latifolia (Oregon ash). The water bodies are located in glacial potholes, river oxbows
, ephemeral ponds, flood plains and other areas that fill with water periodically as snow melts and spring rain falls.
flowers remain closed and self-pollinate, and flowers that bloom above the surface of the water open into white blossoms and may cross with other individuals. Because it often pollinates itself, the species has a low genetic diversity
. Seeds are produced in the water but they require open air for germination
, so they sprout when the wetland has dried in the fall.
and draining and conversion to urban use, alteration of the local hydrology
by placement of dam
s and dikes, deposition of silt
, livestock
activity, introduced species
of plants, low genetic diversity, and climate change.
Campanulaceae
The family Campanulaceae , of the order Asterales, contains about 2000 species in 70 genera of herbaceous plants, shrubs, and rarely small trees, often with milky non-toxic sap...
and is considered to a threatened species since 1994. It is the only species in the monotypic genus Howellia. Thomas Jefferson Howell and Joseph Howell discovered the species in 1878.
Distribution
The Water Howellia is found in large area of the Pacific Northwest region of the United States. It can be found in CaliforniaCalifornia
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...
, Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, and Washington, and it is known historically from Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
.
The plant grows in wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
habitat surrounded by forests, which provide organic material. Associated tree species include Populus trichocarpa
Populus trichocarpa
Populus trichocarpa is a deciduous broadleaf tree species native to western North America. It is used for timber, and is notable as a model organism in plant biology. Its full genome sequence was published in 2006...
(California poplar), P. tremuloides
Populus tremuloides
Populus tremuloides is a deciduous tree native to cooler areas of North America, commonly called quaking aspen, trembling aspen, American aspen, and Quakies,. The trees have tall trunks, up to 25 metres, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden...
(quaking aspen), and Fraxinus latifolia (Oregon ash). The water bodies are located in glacial potholes, river oxbows
Meander
A meander in general is a bend in a sinuous watercourse. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the...
, ephemeral ponds, flood plains and other areas that fill with water periodically as snow melts and spring rain falls.
Biology
The plant produces two types of flowers. Submerged cleistogamousCleistogamy
Cleistogamy or automatic self-pollination describes the trait of certain plants to propagate by using non-opening, self-pollinating flowers...
flowers remain closed and self-pollinate, and flowers that bloom above the surface of the water open into white blossoms and may cross with other individuals. Because it often pollinates itself, the species has a low genetic diversity
Genetic diversity
Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
. Seeds are produced in the water but they require open air for germination
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
, so they sprout when the wetland has dried in the fall.
Conservation
Threats to this species include loss of habitat to loggingLogging
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 draining and conversion to urban use, alteration of the local hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
by placement of dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s and dikes, deposition of silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...
, livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
activity, 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, low genetic diversity, and climate change.