''Howellia aquatilis'', the water howellia, is a small plant in the family
Campanulaceae and was considered a threatened species between 1994 and 2019.
It is the only species in the monotypic genus ''Howellia''.
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
California,
Idaho,
Montana, and
Washington, and it is known historically from
Oregon.
[USFWS Species Profile.]
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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
''Fraxinus latifolia'', the Oregon ash, is a member of the ash genus '' Fraxinus'', native to western North America.
Description
''Fraxinus latifolia'' is a medium-sized deciduous tree that can grow to heights of in height, with a trunk diame ...
'' (Oregon ash).[ The water bodies are located in glacial potholes, river oxbows, ephemeral ponds, ]flood plain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
s and other areas that fill with water periodically as snow melts and spring rain falls.[
]
Biology
The plant produces two types of flowers. Submerged cleistogamous 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 is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is dis ...
.[ Seeds are produced in the water but they require open air for ]germination
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
, so they sprout when the wetland has dried in the fall.[
]
Conservation
Threats to this species include loss of habitat to logging
Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars.
Logging is the beginning of a supply chain ...
and draining and conversion to urban use, alteration of the local hydrology by placement of dams and dikes, deposition of silt, livestock activity, introduced species of plants, low genetic diversity, and climate change.[USFS Wildflowers.]
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References
External links
USDA Plants Profile
{{Taxonbar, from1=Q9005061, from2=Q5921821
Lobelioideae
Monotypic Campanulaceae genera