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Baptisia arachnifera Duncan
Hairy Rattleweed
Federal Protection: Listed Endangered
State Protection: Endangered
Global Rank: G1G2
State Rank: S1S2
Element Locations Tracked in Biotics: Yes
SWAP 2015 Species of Greatest Conservation Need (SGCN): Yes
SWAP 2025 Species of Greatest Conservation Need (SGCN): Yes
2025 SGCN Priority Tier: Highest Conservation Concern
Element Occurrences (EOs) in Georgia: 35
Habitat Summary for element in Georgia: Pine flatwoods
Perennial herb, 15 - 32 inches tall (40 - 80 cm), all parts covered with white, cobwebby hairs. Leaves are 0.8 - 2.4 inches (2 - 6 cm) long and 0.5 - 2 inches (1.5 - 5 cm) wide, simple, alternate, oval to broadly heart-shaped. Flower clusters are elongated, held erect at the top of the stems. The flowers are yellow, typical of pea flowers with an upright banner petal and 2 wing petals enclosing a keel petal. Fruit is a leathery pod, 0.3 - 0.5 inch long and 0.2 - 0.4 inch wide (8 - 12 mm long, 6 - 9 mm wide) long, with a curving tip that is nearly as long as the pod.
Most Baptisia species have compound leaves with 3 leaflets. The only other Baptisia in Georgia with simple leaves is Perfoliate Wild Indigo (Baptisia perfoliata), which has hairless stems and hairless, leathery leaves that completely encircle the stem so that the stem appears to pass through the leaf.
There are five rare Baptisia in Georgia:
Hairy Rattleweed (Baptisia arachnifera) occurs in pine flatwoods in southeast Georgia. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=20990
Glade Blue Wild Indigo (Baptisia australis var. aberrans) occurs in limestone glades and barrens in northwest Georgia. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=17790
Streamside Blue Indigo (Baptisia australis var. australis) occurs on gravel bars and rocky creek banks in northwest Georgia. It has smooth, waxy stems, and blue flowers. For more information, see: https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.160900/Baptisia_australis_var_australis
Leconte’s Wild Indigo (Baptisia lecontei) occurs in sandhills in south-central Georgia; it has yellow flowers, a round pod with a short, pointed tip, and leaves with 3 oval, grayish-green leaflets. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.146356/Baptisia_lecontei
Apalachicola Wild Indigo (Baptisia megacarpa) occurs on well drained, sandy ridges in floodplains, stream terraces, and low, hardwood-dominated slopes in the Chattahoochee River drainage. For more information, see: https://georgiabiodiversity.org/portal/profile?group=plants&es_id=20305
Pine flatwoods with a shrubby layer of Saw Palmetto, Gallberry, Rusty Lyonia, and blueberries; also pine plantations, powerlines, and rights-of-way through flatwoods habitats.
Hairy Rattleweed is a perennial herb that reproduces sexually by seed and vegetatively by widely spreading, rhizomatous rootstocks. Its large rootstock suggests that plants are long-lived. It is probably self-incompatible and relies on insect pollinators to effect cross-pollination. Seeds are dispersed when stems break off at ground level and are blown, tumbleweed-style, across the landscape; weevils may also disperse some seeds. Because of the drastic reduction in population size over the last 20 years, research has focused on possible causes of this decline; one study found that Hairy Rattleweed produces many fewer seeds than a common, closely related Baptisia species, and that its seeds are also heavily eaten by weevils. Another study found that plants require a relatively open canopy to flower, a condition difficult to sustain in the populations that occur in pine plantations.
Hairy Rattleweed flowers late June–early August and fruiting August–October, but the hairy stems and leaves are distinctive throughout the growing season.
Found only in 2 counties in southeast Georgia.
Fire suppression, lowering of water table, site drainage, conversion of habitat to pine plantations.
| Threat 1 | Threat 2 | Threat 3 | |
|---|---|---|---|
| General Threat | Agriculture & aquaculture | Natural system modifications | Invasive & other problematic species, genes & diseases |
| Specific Threat | None | None | None |
Baptisia arachnifera is ranked S1 by the Georgia Department of Natural Resources, indicating that it is critically imperiled in the state. It is listed as Endangered by the U.S. Fish and Wildlife Service and by the state of Georgia. Approximately 30 populations have been documented over the last century, but only a few of these have survived and most are on private timber lands. Most have suffered a drastic reduction in population size and plant growth and reproduction.
Purchase or place under conservation management all lands containing Hairy Rattleweed. Burn flatwoods every 2 - 3 years or, where fire is not practical, selectively cut trees to permit more sunlight to reach the plants. Avoid clearcutting and other mechanical disturbances such as bedding and roller drum chopping. Continue yearly monitoring of populations and support research into causes of decline.
Ceska, J.F., J.M. Affolter, and J.L. Hamrick. 1997. Developing a sampling strategy for Baptisia arachnifera based on allozyme diversity. Conservation Biology 11(5): 1133-1139. https://conbio.onlinelibrary.wiley.com/doi/abs/10.1046/j.1523-1739.1997.95527.x
Chafin, L.G. 2007. Field guide to the rare plants of Georgia. State Botanical Garden of Georgia and University of Georgia Press, Athens.
Chapman, D. 2020. Learning to love a hairy rattleweed: strangely named rare plant makes a recovery comeback in Georgia. U.S. Fish and Wildlife Service, Atlanta. https://www.fws.gov/southeast/articles/learning-to-love-a-hairy-rattleweed/
Duncan, W.H. 1944. A new species of Baptisia. Rhodora 46:29-31. https://www.jstor.org/stable/23302295?seq=1#metadata_info_tab_contents
Duncan, W.H. and M.B. Duncan. 1999. Wildflowers of the eastern United States. University of Georgia Press, Athens.
Estep, T.J. 2011. Evaluating restoration potential of an endangered legume, Baptisia arachnifera: shade and litter effects on early life stages. M.S. Thesis, Georgia Southern University. Electronic Theses and Dissertations 760. https://digitalcommons.georgiasouthern.edu/etd/760
Faircloth, W.R. 1987. Doomsday looms in the pine barrens: Baptisia arachnifera is dwindling. Tipularia 1(2): 2-6.
GADNR. 2019. Element occurrence records for Baptisia arachnifera. Georgia Department of Natural Resources, Wildlife Resources Division, Social Circle, Georgia.
Isely, D. 1990. Vascular flora of the southeastern United States, Vol. 3, Part 2, Leguminosae (Fabaceae). University of North Carolina Press, Chapel Hill.
Kral, R. 1983. A report on some rare, threatened, or endangered forest-related vascular plants of the South. Technical Publication R8-TP2. United States Forest Service, Atlanta.
NatureServe. 2019. Baptisia arachnifera comprehensive species report. NatureServe Explorer. Arlington, Virginia. http://explorer.natureserve.org/servlet/NatureServe?searchName=Baptisia%20arachnifera
Patrick, T.S., J.R. Allison, and G.A. Krakow. 1995. Protected plants of Georgia. Georgia Department of Natural Resources, Natural Heritage Program, Social Circle.
USFWS. 2018. Hairy Rattleweed (Baptisia arachnifera) species profile. U.S. Fish and Wildlife Service, Washington, D.C. https://ecos.fws.gov/ecp0/profile/speciesProfile?sId=8029http://endangered.fws.gov.
Weakley, A.S. 2015. Flora of the southern and mid-Atlantic States. University of North Carolina Herbarium, University of North Carolina, Chapel Hill.
Young, A.S., S.-M. Chang, and R.R. Sharitz. 2007. Reproductive ecology of a federally endangered legume, Baptisia arachnifera, and its more widespread congener, B. lanceolata. American Journal of Botany 94: 228-236. https://bsapubs.onlinelibrary.wiley.com/doi/pdf/10.3732/ajb.94.2.228
Linda G. Chafin
L. Chafin, Feb. 2007: original account.
K. Owers, Jan. 2010: updated status and ranks, added pictures.
Z. Abouhamdan, April 2016: removed broken link.
L. Chafin, June 2020: updated original account.
