Lesquerella pallida
Encyclopedia
Lesquerella 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
.
This is an annual herb growing mostly erect to a height of 30 to 60 centimeters. The leaves may be any of a variety of shapes and have smooth, toothed, or lobed edges. The longest near the base of the plant can reach 10 centimeters in length. The inflorescence
is a raceme
of flowers with oval white petals that narrow near the yellowish bases and measure just over a centimeter long. The fruit is a spherical silique
which is variable in size.
This plant was discovered in the 1830s but not seen again until its rediscovery in 1981. It has never been found outside of San Augustine County, Texas. There are six populations. The plant grows on openings in oak, hickory, and pine woods. It is limited to a part of the Piney Woods
region on the Gulf Coastal Plain
where there is alkaline soil derived from the Weches Formation. This geologic formation
contains carbonates above a layer of water-impermeable glauconite
, which keeps the soil above from draining, leaving the area quite moist. Most of the soils in eastern Texas are acidic, but the calcium and magnesium minerals in this formation make it alkaline. Other rare plants that occur on the Weches Formation include Sedum pulchellum, Calylophus drummondianus, Liatris mucronata, Paronychia virginica, Petalostemum pulcherrimum, Heliotropium tenellum, Eleocharis compressa, and Cuphea viscosissima
.
This plant is threatened by the loss and degradation of its habitat, which has largely been converted to agricultural and pasture use and dug up during gravel mining
operations. Glauconite gravel is used for road surfacing. The ecological succession
of brush and woody vegetation into the clearings on which it depends also threatens the plant. It does not tolerate competition with other plants. Habitat conservation
activities include the removal of brush and vegetation buildup by mechanical means or with herbicide
s or fire. Most of the populations occur on private property, so conservation will depend on the cooperation of landowners.
Brassicaceae
Brassicaceae, a medium sized and economically important family of flowering plants , are informally known as the mustards, mustard flowers, the crucifers or the cabbage family....
known by the common name white bladderpod. It is endemic to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
in the United States, where it is known only from San Augustine County
San Augustine County, Texas
As of the census of 2000, there were 8,946 people, 3,575 households, and 2,520 families residing in the county. The population density was 17 people per square mile . There were 5,356 housing units at an average density of 10 per square mile...
. It is federally listed as an 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...
.
This is an annual herb growing mostly erect to a height of 30 to 60 centimeters. The leaves may be any of a variety of shapes and have smooth, toothed, or lobed edges. The longest near the base of the plant can reach 10 centimeters in length. 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 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...
of flowers with oval white petals that narrow near the yellowish bases and measure just over a centimeter long. The fruit is a spherical silique
Silique
A silique or siliqua is a fruit of 2 fused carpels with the length being more than three times the width. The outer walls of the ovary usually separate when ripe, leaving a persistent partition...
which is variable in size.
This plant was discovered in the 1830s but not seen again until its rediscovery in 1981. It has never been found outside of San Augustine County, Texas. There are six populations. The plant grows on openings in oak, hickory, and pine woods. It is limited to a part of the Piney Woods
Piney Woods
The Piney Woods is a temperate coniferous forest terrestrial ecoregion in the Southern United States covering of East Texas, southern Arkansas, western Louisiana, and southeastern Oklahoma. These coniferous forests are dominated by several species of pine as well as hardwoods including hickory and...
region on the Gulf Coastal Plain
Gulf Coastal Plain
The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico.The plain reaches from the western Florida Panhandle, the southwestern two thirds of Alabama, over most of Mississippi, some of western Tennessee and Kentucky, southwest Arkansas, the Florida...
where there is alkaline soil derived from the Weches Formation. This geologic formation
Geologic formation
A formation or geological formation is the fundamental unit of lithostratigraphy. A formation consists of a certain number of rock strata that have a comparable lithology, facies or other similar properties...
contains carbonates above a layer of water-impermeable glauconite
Glauconite
Glauconite is an iron potassium phyllosilicate mineral of characteristic green color with very low weathering resistance and very friable.It crystallizes with a monoclinic geometry...
, which keeps the soil above from draining, leaving the area quite moist. Most of the soils in eastern Texas are acidic, but the calcium and magnesium minerals in this formation make it alkaline. Other rare plants that occur on the Weches Formation include Sedum pulchellum, Calylophus drummondianus, Liatris mucronata, Paronychia virginica, Petalostemum pulcherrimum, Heliotropium tenellum, Eleocharis compressa, and Cuphea viscosissima
Cuphea viscosissima
Cuphea viscosissima, also known as blue waxweed, clammy cuphea or as "tarweed", is a plant native to the United States. It is a potential source of edible oil for humans....
.
This plant is threatened by the loss and degradation of its habitat, which has largely been converted to agricultural and pasture use and dug up during gravel mining
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
operations. Glauconite gravel is used for road surfacing. The ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
of brush and woody vegetation into the clearings on which it depends also threatens the plant. It does not tolerate competition with other plants. Habitat conservation
Habitat conservation
Habitat conservation is a land management practice that seeks to conserve, protect and restore, habitat areas for wild plants and animals, especially conservation reliant species, and prevent their extinction, fragmentation or reduction in range...
activities include the removal of brush and vegetation buildup by mechanical means or with 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 or fire. Most of the populations occur on private property, so conservation will depend on the cooperation of landowners.