Leavenworthia crassa

Leavenworthia crassa
Conservation status
	; Imperiled (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Brassicales
Family:	Brassicaceae
Genus:	Leavenworthia
Species:	L. crassa
Binomial name
	Leavenworthia crassa; Rollins

Last updated August 21, 2024

Leavenworthia crassa is a species of flowering plant in the mustard family, Brassicaceae, known commonly as the fleshy-fruit gladecress. It is endemic to Alabama in the United States, where it occurs in only two counties. It is "likely one of the most imperiled plant species in the Southeast,"^[1] and the United States Fish and Wildlife Service issued a final rule listing it as an endangered species in 2014.^[2]^[3]

Description

This plant is variable in appearance. Its morphology is determined by its genes rather than environmental conditions, and it reflects the variable breeding system of the species.^[4] Some individuals are self-incompatible and must receive pollen from other plants in order to reproduce, while others can fertilize themselves. Populations of the species have both self-incompatible and self-fertilizing individuals, but some populations are almost entirely selfing.^[5] Self-incompatible plants have a morphology that encourages pollen transfer: the flowers are large and aromatic and have anthers that are extrorse, facing outward. These plants also have two flower color morphs. Self-compatible plants have smaller, barely scented flowers with introrse, or inward-facing anthers.^[4]

This annual herb forms a rosette of leaves but usually has no stem. Flowers are borne on long pedicels that emerge from bracts hidden in the leaf rosette. In favorable conditions the plant may later grow a stem with an inflorescence.^[6]

The leaves have blades up to 8 centimeters long which have one to eight lobes on each edge, with the largest one at the tip. The margins are smooth or toothed. The pedicels holding the flowers are 4 to 8 centimeters long. The flower has 4 petals, each 1 to 1.4 centimeters long with a notch in the tip. The two petal color morphs are white and yellow, but all the petals have yellow or orange bases. The fruit is a smooth, oblong or somewhat rounded silicle up to about 1.4 centimeters long. The winged seeds are roughly 2 or 3 millimeters long.^[7]

Ecology

Cedar glade Cedar-glade-col-tn2.jpg — Cedar glade

Like other species in the small genus Leavenworthia , this plant is adapted to cedar glade habitat. These glades are sunny openings in woods dominated by eastern red cedar (Juniperus virginiana). They have thin soils over sheets of limestone, with many bare rock and gravel outcroppings. The soils are very wet during the winter and spring and very dry in the summer. The species requires the full sun of this open habitat type and cannot survive in shady areas. Other plants in the habitat include Tennessee milkvetch (Astragalus tennesseensis), Alabama gladecress (Leavenworthia alabamica), Michaux's gladecress (Leavenworthia uniflora), dwarf larkspur (Delphinium tricorne), smooth rockcress (Boechera laevigata), yellow sunnybell (Schoenolirion croceum), and small skullcap (Scutellaria parvula).^[8]

Pollinators of the outcrossing plants probably include halictid bees such as Halictus ligatus .^[2]

Conservation

This plant grows at six small sites within a 13-mile radius in Lawrence and Morgan Counties in northern Alabama. Some populations are very small, but in some areas the plant is locally abundant. The total population size was approximately 12,000 individuals in 2009.^[1] Most of the occurrences are on privately owned land. One site is in a protected area in William B. Bankhead National Forest.^[2]

A main threat to the species is the loss and disturbance of its cedar glade habitat. About 50% of the region's cedar glades have been lost since European settlement, and remaining glades are fragmented and altered by grazing, cultivation, and residential development. Many are affected by activity related to roadways, such as herbicides, road construction, grading, trash dumping, and off-road vehicles. Modified glades no longer maintain themselves through the natural processes of drought, wildfire, and erosion, and the openings shrink as woody vegetation closes in. The sunny open spots required by the plant are reduced. The process is hastened by invasive species of plants, especially common privet (Ligustrum vulgare) and bush honeysuckle (Lonicera maackii).^[2]

The proposal to list the plant as an endangered species was made because it "is in danger of extinction throughout all or a significant portion of its range."^[2]

Related Research Articles

Leavenworthia stylosa is a species of flowering plant in the family Brassicaceae known by the common names cedar gladecress or long-styled gladecress. It is found only in the Central Basin of Tennessee, where it grows in cedar glades, ditches, and low-lying fields. It is an annual herb growing up to 3 in (7.6 cm) tall.

Physaria is a genus of flowering plants in the family Brassicaceae. Many species are known generally as twinpods, bladderpods, or lesquerella. They are native to the Americas, with many species endemic to western North America. They are densely hairy annual and perennial herbs often growing prostrate or decumbent, along the ground in patches or clumps. They bear inflorescences of bright yellow flowers. The fruit is often notched deeply, dividing into twin sections, giving the genus its common name.

Physaria chambersii is a species of flowering plant in the family Brassicaceae known by the common name Chambers' twinpod. It is native to the southwestern United States, where it grows in desert woodland and plateau habitat. It is a perennial herb growing from a taproot and producing a clumpy rosette of stems up to 15 centimeters long, growing erect and falling over in fruit. The plant is covered in a silver-white coat of hairs. The leaves in the rosette are rounded to oval, up to 6 centimeters long by 2 wide, and smaller, spoon-shaped leaves are located along the stems. The inflorescence is a raceme of four-petalled golden yellow flowers. The fruit is an inflated pod which may be over a centimeter long. It is notched and divided into two chambers, each containing 4 seeds.

Paysonia lyrata is a rare species of flowering plant in the family Brassicaceae known by the common name lyreleaf bladderpod. It is endemic to Alabama in the United States, where it is known from only three occurrences. It is federally listed as a threatened species.

<i>Physaria filiformis</i> Species of plant

Physaria filiformis is a rare species of flowering plant in the family Brassicaceae known by the common names Missouri bladderpod and limestone glade bladderpod. It is native to Missouri and Arkansas in the United States. It was federally listed as an endangered species in 1987 and it was downlisted to threatened status in 2003. P. filiformis remains listed as an endangered species at the state level in Missouri.

Physaria obcordata is a rare species of flowering plant in the family Brassicaceae known by the common name Dudley Bluffs twinpod. It is similar in appearance to the more common Piceance twinpod, but can be distinguished by looking at the leaves through a hand lens. The Piceance twinpod, Physaria acutifolia has stellate hairs when viewed through a hand lens while Physaria ocordata has markings that look like a satellite dish, or a circle with a dot in the middle. It is endemic to Colorado, where it is found only in the Piceance Basin in Rio Blanco County. It is threatened by the loss and degradation of its habitat. It is a federally listed threatened species of the United States.

Physaria globosa is a rare flowering plant in the mustard family commonly known as globe bladderpod, Short's bladderpod, and Lesquereux's mustard. It is endemic to the United States, where it is limited to Indiana, Kentucky, and Tennessee. It is a rare species throughout its range and in 2014 the U.S. Fish and Wildlife Service issued a final rule protecting it under the Endangered Species Act.

Physaria parviflora is a species of flowering plant in the family Brassicaceae known by the common names Piceance bladderpod and frosty bladderpod. It is endemic to Colorado in the United States, where it occurs in Garfield, Mesa, and Rio Blanco Counties.

Physaria fremontii is a species of flowering plant in the family Brassicaceae known by the common name Fremont's bladderpod. It is endemic to Wyoming in the United States, where it occurs only in and around the Wind River Range in Fremont County.

Leavenworthia is a genus of flowering plants in the family Brassicaceae. It includes about eight species native to the southern and southeastern United States. They are known generally as gladecresses.

Physaria tenella is a species of flowering plant in the family Brassicaceae known by the common names Moapa bladderpod and slender bladderpod. It is native to western North America from Utah to Sonora, where it grows mainly in desert habitat. This is an annual herb producing several hairy multibranched erect to spreading stems sometimes exceeding half a meter long. The basal leaves are up to 6.5 centimeters long and sometimes toothed, and there are smaller leaves higher on the stem. The inflorescence is a raceme of flowers at the tip of the stem. The mustardlike flower has four orange to bright yellow petals each up to a centimeter long. The fruit is a plump, hairy, rounded capsule containing flat orange seeds.

Physaria pallida is a rare species of flowering plant in the mustard family known by the common name white bladderpod. It is endemic to Texas in the United States, where it is known only from San Augustine County. It is federally listed as an endangered species.

Physaria congesta is a rare species of flowering plant in the mustard family known by the common name Dudley Bluffs bladderpod. It is endemic to western Colorado in the United States, where it is known only from seven occurrences in Rio Blanco County. It is federally listed as a threatened species.

<i>Physaria kingii</i> Species of flowering plant

Physaria kingii is a species of flowering plant in the family Brassicaceae known by the common name King bladderpod. It is native to western North America from Utah to Baja California, where it grows in dry and rocky habitat, such as deserts and adjacent mountain slopes. This is a perennial herb growing a small, hairy stem from a caudex. The leaves form a patch or rosette around the caudex, each up to 6 centimeters long and round, oval, diamond, or spoonlike in shape. The inflorescence is an erect or mostly upright raceme of bright yellow mustardlike flowers. The fruit is a hairy capsule under a centimeter long suspended on a short, often curvy pedicel.

Physaria parvula is a species of flowering plant in the family Brassicaceae known by the common name pygmy bladderpod. It is native to the Western United States, where it can be found in Colorado, Utah, and Wyoming.

Physaria pruinosa is a species of flowering plant in the family Brassicaceae known by the common names Pagosa Springs bladderpod and frosty bladderpod. It is native to Colorado and New Mexico in the United States.

Physaria thamnophila is a rare species of flowering plant in the mustard family known by the common name Zapata bladderpod. It is native to Texas in the United States, where it is known from Zapata and Starr Counties. The plant is threatened by the loss and degradation of its habitat. It is federally listed as an endangered species.

Physaria tumulosa, known by the common name Kodachrome bladderpod, is a rare species of flowering plant in the family Brassicaceae. It is endemic to Utah in the United States, where it is known only from Kane County. There is only one known population of this plant, made up of scattered occurrences totaling about 20,000 individuals, all within the Kodachrome Basin. The plant is threatened by the loss and degradation of its habitat. It is federally listed as an endangered species. It was previously treated as a subspecies of Physaria hitchcockii.

Physaria ludoviciana is a species of flowering plant in the mustard family Brassicaceae, with the common names of bladder pod, silver bladderpod, louisiana bladderpod, and foothill bladderpod. It used to be Lesquerella ludoviciana which is now a synonym.

Leavenworthia alabamica is a species of flowering plant in the family Brassicaceae. It is commonly known as Alabama gladecress. It is endemic to Alabama.

References

1 2 3 Leavenworthia crassa. NatureServe 2013.
1 2 3 4 5 USFWS. Endangered status for Physaria globosa (Short's bladderpod), Helianthus verticillatus (whorled sunflower), and Leavenworthia crassa (fleshy-fruit gladecress). Federal Register 78(149) 47109-34. August 2, 2013.
↑ Remillard, Ashley (August 4, 2014) "U.S. Fish and Wildlife Service Issues Final Rule Protecting Three Flowers" Archived 2014-08-12 at the Wayback Machine Endangered Species Law and Policy Blog, Nossaman LLP
1 2 Lyons, E. E. and J. Antonovics. (1991). Breeding system evolution in Leavenworthia: breeding system variation and reproductive success in natural populations of Leavenworthia crassa (Cruciferae). American Journal of Botany 78(2), 270-87.
↑ Liu, F., et al. (1999). The effect of mating system differences on nucleotide diversity at the phosphoglucose isomerase locus in the plant genus Leavenworthia. Genetics 151(1), 343-57.
↑ Liu, N., et al. (2011). Possible contributions of TERMINAL FLOWER 1 to the evolution of rosette flowering in Leavenworthia (Brassicaceae). New Phytologist 189(2), 616-28.
↑ Leavenworthia crassa. Flora of North America.
↑ USFWS. Designation of critical habitat for Physaria globosa (Short's bladderpod), Helianthus verticillatus (whorled sunflower), and Leavenworthia crassa (fleshy-fruit gladecress). Federal Register 78(149), 47060-108. August 2, 2013.