Baptisia arachnifera is an endangered perennial plant in the pea family that is endemic to only two counties within South Georgia. The isolated habitats lie within Wayne and Brantley Counties, in a ten-square mile area near Jesup. The hairy rattleweed gets its name arachnifera, which means spider-bearing, from the silvery-white, cobwebby hairs that cover the stem, leaves and bean pods; and the seeds that rattle inside the pods when mature and dry.
A reduction in numbers of individual plants has been observed during the past 50 years and since the late 1980s, an increasing number of biologists have attempted to bring this fact to light.
This flowering legume produces multiple branches and stands between 20 and 32 inches tall. It possesses a reddish-brown stem that is densely covered by silvery-white hairs. Its leathery leaves are rounded or heart-shaped and alternate as they grow along both sides of the stem. The leaves measure between 1.2 and 3.2 inches long and 0.8 to 3.8 inches wide. The leaves’ upper surface is green while the underside is yellowish and covered with long, silvery-white hairs like the stem.
In late June to July, the plant produces bright yellow flowers with five petals. The flowers are pea-like and grow in erect clusters at the branch tips above the leaves. In late summer the plant produces fruits in the form of bean pods. As stated earlier, the pods are densely covered with silvery-white hairs and its seeds rattle inside the pod as they mature and dry.
This species thrives in the Coastal Plain of Georgia in open flat woods with seasonally wet, sandy soils. It is found in shallow pools on Piedmont granite outcrops in full sunlight. Pools dry out in Summer and the seeds can lie dormant over several seasons until moisture is available. Shade, drainage, and silting-in of pools will destroy habitat.
Anthropogenic factors rank highest among the causes for this species habitat destruction. Many of the individual plants lie in lands owned by Rayonier, a local paper and pulp-producing plant, and a majority of the destruction occurs as machinery is brought in to harvest timber.
One consensus among researchers states that while habitat destruction plays a key role in the loss of this species, insects and climate conditions are also factors for this species reduction in the wild. Heat causes germination in these hard-seeded legumes. Whenever this germination occurs outside of this Baptisia species ideal window of growth, many of these heavy seeds fail to produce viable young plants. Baptisia lanceolata, which is a heartier relative, produces a seed that remains viable at much higher temperatures thus proving its sustainability as a stronger colonizer over B. arachnifera.
Biologists studying these species noted that while the B. arachnifera populations near Jesup are somewhat close in proximity, they do exist in Hardy-Weinberg equilibrium. Indirect evidence of gene flow was detected; therefore the close proximity of the populations and the recent reduction in population sizes suggest that the populations surveyed may be fragments of a once more continuous gene pool.
Interest from students from both the University of Georgia and Valdosta State University have aided in this plants’ proliferation since the middle of our current decade. In 2004 and 2005, the students studied and mapped the existing populations as well as obtained seeds to maintain an ex situ collection – an off-site conservation facility designed to foster population growth for future studies.
Difficulties arise around this endangered species because there are few available species or gene combinations with fitness enough to sustain themselves without help from ecologists, state and federal conservation groups. The wild species are used to revitalize domesticated species. As more education about these endangered species arises, individuals realize that the loss of B. arachnifera could result in loss of human life. The loss of biodiversity can harm our own lives in ways that are hard to determine. Accelerated extinction rates are a powerful message that ecosystems surrounding us are being severely damaged.
As more information becomes available, the realization of endangered species’ importance also becomes more prevalent. Species preservation provides opportunities for improved crop production through crossbreeding with related wild species. It also provides opportunities for new medicines and industrial chemicals from substances found naturally only in the wild – for these reasons alone, biodiversity is becoming economically valuable. In attempts to preserve Baptisia arachnifera for future generations, this flowering legume has been designated an endangered species by both the United States Fish and Wildlife Service and the Georgia Department of Natural Resources.
