Sidalcea nelsoniana
Encyclopedia
Sidalcea nelsoniana is a rare species of flowering plant in the mallow family
known by the common names Nelson's checkerbloom and Nelson's checkermallow. It is native to the Willamette Valley
and Coast Range of Oregon
and the southwestern corner of Washington in the United States. It is threatened by the destruction and degradation of its habitat, and it is a federally listed threatened species of the United States.
This plant is a perennial herb producing several erect stems up to a meter tall from a thick taproot
. The blades of the leaves are variable in shape. In general, the basal leaves are palmate
in shape and the upper leaves are more deeply divided. Each stem can bear up to 100 pink flowers in a spikelike raceme
. The species is gynodioecious
, producing bisexual flowers and female flowers that lack the ability to produce pollen
. Each flower has a purple-tinged calyx of sepal
s and five petals up to 1.5 centimeters in length. The fruit is a schizocarp
with one seed in each of its seven to nine segments. Blooming occurs in late May through mid-July. The plants reproduce sexually
via seed and vegetatively
by sprouting from broken-off pieces of the root.
This plant can be found in a number of wetland
habitat types and is not limited to a specific kind.
It grows in wet open habitat such as sedge
and grass meadows and the transition zone from prairie
to woodland
. It can grow on sunny forest edges and in riparian
habitat and it is tolerant of disturbance, occurring even near campgrounds.
There are six main population centers, four in the Willamette Valley and one each in the Coast Range and southwestern Washington State. The latter is made up of two populations. A large population is present in William L. Finley National Wildlife Refuge
. The largest population in the Oregon Coast Range is located at Walker Flat in Yamhill County
. Most populations are small. About 48% of them contain fewer than 100 plants and 31% contain under 25.
This plant faces a number of threats. Fire suppression is a main threat because the habitat becomes overgrown with thick vegetation in the absence of the normal fire regime
that maintains open clearings. Wildfire
s are beneficial for this plant, because they clear the large and woody vegetation that prevent sunlight from reaching it.
Despite the plant's tolerance of disturbance, populations occurring near roads and cultivated fields are vulnerable. Many populations in the Willamette Valley are threatened or already extirpated
by agricultural and urban development. Over the last 150 years 99% of the wetland habitat in the Willamette Valley has been altered or destroyed. The possible future construction of a dam
threatens a large population. Even in protected areas the plant is threatened by the invasion
of non-native plant species
. Such weeds include reed canary grass
(Phalaris arundinacea).
Other threats include herbicide
s and predation by the weevil
Macrohoptus sidalceae. This checkerbloom is known to hybridize with its Sidalcea
relatives, such as Sidalcea cusickii, a process that can lead to genetic pollution
of the rare plant.
Malvaceae
Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...
known by the common names Nelson's checkerbloom and Nelson's checkermallow. It is native to the Willamette Valley
Willamette Valley
The Willamette Valley is the most populated region in the state of Oregon of the United States. Located in the state's northwest, the region is surrounded by tall mountain ranges to the east, west and south and the valley's floor is broad, flat and fertile because of Ice Age conditions...
and Coast Range of Oregon
Oregon Coast Range
The Oregon Coast Range, often called simply the Coast Range and sometimes the Pacific Coast Range, is a mountain range, in the Pacific Coast Ranges physiographic region, in the U.S. state of Oregon along the Pacific Ocean...
and the southwestern corner of Washington in the United States. It is threatened by the destruction and degradation of its habitat, and it is a federally listed threatened species of the United States.
This plant is a perennial herb producing several erect stems up to a meter tall from a thick taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
. The blades of the leaves are variable in shape. In general, the basal leaves are palmate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
in shape and the upper leaves are more deeply divided. Each stem can bear up to 100 pink flowers in a spikelike raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
. The species is gynodioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, producing bisexual flowers and female flowers that lack the ability to produce pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
. Each flower has a purple-tinged calyx of sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s and five petals up to 1.5 centimeters in length. The fruit is a schizocarp
Schizocarp
A schizocarp is a dry fruit that develops from multiple carpels. When mature it splits up into mericarps. Mericarps are often 1-seeded as in, for example, Malva, Malvastrum, and Sida...
with one seed in each of its seven to nine segments. Blooming occurs in late May through mid-July. The plants reproduce sexually
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
via seed and vegetatively
Vegetative reproduction
Vegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores...
by sprouting from broken-off pieces of the root.
This plant can be found in a number of 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 types and is not limited to a specific kind.
It grows in wet open habitat such as sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
and grass meadows and the transition zone from prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...
to woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
. It can grow on sunny forest edges and in riparian
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
habitat and it is tolerant of disturbance, occurring even near campgrounds.
There are six main population centers, four in the Willamette Valley and one each in the Coast Range and southwestern Washington State. The latter is made up of two populations. A large population is present in William L. Finley National Wildlife Refuge
William L. Finley National Wildlife Refuge
William L. Finley National Wildlife Refuge is a natural area in the Willamette Valley in Oregon, United States. It was created to provide wintering habitat for Dusky Canada Geese. Unlike other Canada Geese, Dusky Canada Geese have limited summer and winter ranges. They nest on Alaska's Copper River...
. The largest population in the Oregon Coast Range is located at Walker Flat in Yamhill County
Yamhill County, Oregon
-National protected areas:*Siuslaw National Forest *Tualatin River National Wildlife Refuge -Demographics:As of the census of 2000, there were 84,992 people, 28,732 households, and 21,376 families residing in the county. The population density was 119 people per square mile . There were 30,270...
. Most populations are small. About 48% of them contain fewer than 100 plants and 31% contain under 25.
This plant faces a number of threats. Fire suppression is a main threat because the habitat becomes overgrown with thick vegetation in the absence of the normal fire regime
Fire regime
A fire regime is the pattern, frequency and intensity of the bushfires and wildfires that prevails in an area. It is an integral part of fire ecology, and renewal for certain types of ecosystems. If fires are too frequent, plants may be killed before they have matured, or before they have set...
that maintains open clearings. Wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
s are beneficial for this plant, because they clear the large and woody vegetation that prevent sunlight from reaching it.
Despite the plant's tolerance of disturbance, populations occurring near roads and cultivated fields are vulnerable. Many populations in the Willamette Valley are threatened or already 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...
by agricultural and urban development. Over the last 150 years 99% of the wetland habitat in the Willamette Valley has been altered or destroyed. The possible future construction of a 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...
threatens a large population. Even in protected areas the plant is threatened by the invasion
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....
of non-native plant 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 weeds include reed canary grass
Reed canary grass
Reed canarygrass, Phalaris arundinacea, is a tall, perennial bunchgrass that commonly forms extensive single-species stands along the margins of lakes and streams and in wet open areas, with a wide distribution in Europe, Asia, northern Africa and North America.-Description:The stems can reach 2.5...
(Phalaris arundinacea).
Other threats include herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
s and predation by the weevil
Weevil
A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...
Macrohoptus sidalceae. This checkerbloom is known to hybridize with its Sidalcea
Sidalcea
Sidalcea is a genus of the botanical family Malvaceae. It contains several species of flower known generally as checkerblooms or checkermallows.Selected species:*Sidalcea calycosa - annual checkerbloom...
relatives, such as Sidalcea cusickii, a process that can lead to genetic pollution
Genetic pollution
Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. This gene flow is undesirable according to some environmentalists and conservationists, including groups such as Greenpeace, TRAFFIC, and GeneWatch UK.-Usage:...
of the rare plant.