FWS Focus

Overview

Characteristics
Overview

Fleshy-fruit gladecress is a winter annual, spring-flowering member of the mustard family that is only found in Alabama. Threats to fleshy-fruit gladecress from habitat destruction and modification occur throughout the entire range of the species. These threats include agricultural conversion or incompatible practices, maintenance of transportation rights-of-way, residential and industrial development and shading and competition. We expect population-level effects from these activities to continue into the future. While the conservation efforts of the U.S. Forest Service have reduced threats associated with off-road vehicle use and encroachment of invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species
at one site, no existing regulations protect the species on privately owned land, which is where all but one of the remnant fleshy-fruit gladecress populations occur. The small number of populations, compounded by the small size of those populations within the limited range of this species are also substantial threats. Despite its restricted and fragmented geographic range and small population sizes, we consider the recovery potential to be high because threats to the species’ habitat are reasonably well understood and manageable.

Scientific Name

Leavenworthia crassa
Common Name
fleshyfruit gladecress
Fleshy-fruit gladecress
FWS Category
Flowering Plants
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Physical Characteristics

Fleshy-fruit gladecress is a component of glade flora and historically occurs in association with limestone outcroppings with exposed rock and shallow soil. Fleshyfruit gladecress grows in open sections of glades but not in adjacent shaded forests, grows best in full sun, and competes poorly with plants that shade them. As with most cedar glade endemics, fleshy-fruit gladecress exhibits weedy tendencies, and it is not uncommon to find the species growing in altered habitats. Populations are also located in glade-like remnants exhibiting various degrees of disturbance, including pastures, roadside rights-of-way, and cultivated or plowed fields. When winter annuals such as fleshy-fruit gladecress grow in habitats with deep soils that retain moisture in summer, plowing, mowing or some other form of disturbance destroys plant competitors.  

The glade habitats that support Leavenworthia species are extreme environments. Cedar glades fluctuate between very wet (winter and early spring) and very dry (summer) conditions. The frequently hot, dry summers create xeric conditions that regulate competition and shading from encroaching vegetation. Fire likely serves to limit encroachment of competitors as well as invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species
where litter accumulation and soil development occur on the periphery of glades but is less of a factor in habitat maintenance than in limestone glades in the Midwest and Ozarks. 

Size & Shape

Fleshy-fruit gladecress was described by R.C. Rollins in 1963 from material collected in Morgan County, Alabama. He noted that fleshy-fruit gladecress is a glabrous winter annual from 1 to 4 decimeters tall, with leaves that grow as a basal rosette and are lyrately pinnatifid. The terminal leaf lobe is conspicuously larger than lateral lobes. Early season flowers are solitary, with racemes appearing later in the season. In general, flowers are on elongate stems and are approximately 9 to 14 millimeters long. The sepals and petals are widely spreading, the petals with a deeply emarginate apex, or having the margin notched. The petals are either yellow with orange or white with yellow, and usually with both color forms intermixed in a single population. In populations of this species that are capable of self-fertilization, stamens tend to be directed toward the inside of the flower, or introrse. Self-incompatible populations tend to have extrorse stamens, as documented by D.G. Lloyd in 1965 and confirmed later by E. Lyons and J. Antovics in 1991. The fruit is globeshaped, or slightly more elongate, and about 12 millimeters long, with a slender beak at the tip.

Characteristic category

Life Cycle

Characteristics
Reproduction

Fleshy-fruit gladecress exhibits a mixture of two mating systems, self-compatibility and self-incompatibility in fertilization. Populations tend to exhibit one mating system or the other and are easily identifiable by flower characteristics. Self-compatible flowers are small and white, while self-incompatible flowers are large and either yellow or white. Self-compatible plants do not require insect pollinators and can mature seeds earlier than self-incompatible plants, which must have favorable temperatures for insect flight and subsequent pollination. Populations with self-compatible fertilization tend to have larger populations than self-incompatible populations.

Life Cycle

Fleshy-fruit gladecress is a winter annual that completes the main stages of the lifecycle - seed, seedling, juvenile, flowering and fruiting - in a single year, as documented by C.C. Baskin and J.M. Baskin in 1971. The seeds germinate from September to October, with plants overwintering as rosettes. The flowers bloom in March and April, as documented by R.C. Rollins in 1963, which are pollinated by generalist bee species, as observed by D.G. Lloyd in 1969. Fruit maturation takes approximately two to three weeks, as documented by O.T. Solbrig and R.C. Rollins in 1977. The first seeds mature in late April and during most years, the plants have died and dropped their seeds by the end of May, as documented by C.C. Caudle and J.M. Baskin in 1968. Seed dispersal appears to be mostly by water, and partially by wind, as documented by D.G. Lloyd in 1965, though the limited natural dispersal capacity of the species has likely been augmented by cattle, mowing equipment or other vehicle traffic on disturbed sites. The reproductive effort, meaning the weight of seeds when compared to the total weight of plant, in field-grown plants ofthis species in relation to a subset of congeners is: L. crassa, 21.1%; L. alabamica, 26.9%; L. stylosa, 33.2 and %. L. exigua, 36.4%, as documented by O.T. Solbrig and R.C. Rollins in 1977. Annual colonizers may allocate up to 30% of their biomass to reproduction, noted Harper and others in 1970. Studies on plant survival and subsequent reproduction have not been conducted for this species.

Characteristic category

Habitat

Characteristics
Habitat

Fleshy-fruit gladecress is a component of glade flora and historically occurs in association with limestone outcroppings with exposed rock and shallow soil. This species grows in open sections of glades, but not in adjacent shaded forests, and grows best in full sun, as it competes poorly with plants that shade them. As with most cedar glade endemics, fleshy-fruit gladecress exhibits weedy tendencies, and it is not uncommon to find the species growing in altered habitats. Populations are also located in glade-like remnants exhibiting various degrees of disturbance, including pastures, roadside rights-of-way and cultivated or plowed fields. When winter annuals like fleshy-fruit gladecress grow in habitats with deep soils that retain moisture in summer, plowing, mowing or some other form of disturbance destroys plant competitors.  

The glade habitats that support Leavenworthia species are extreme environments. Cedar glades fluctuate between very wet during the winter and early spring, to very dry during summer conditions. The frequently hot, dry summers create xeric conditions that regulate competition and shading from encroaching vegetation. Fire likely serves to limit encroachment of competitors, as well as invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species
, where litter accumulation and soil development occur on the periphery of glades. This is less of a factor in habitat maintenance than in limestone glades in the midwest and Ozarks, as documented by C.C. Baskin and J.M. Baskin in 2000. 

Geography

Characteristics
Range

There are 10 occurrences of fleshy-fruit gladecress in eight populations in the Moulton and Tennessee valleys in Alabama, with one occurrence newly discovered since listing. 

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