Orbexilum virgatum

Orbexilum virgatum (Nutt.) Rydb.
Slender Leather-root

Federal Protection: No US federal protection

State Protection: No Georgia state protection

Global Rank: G1

State Rank: SH

Element Locations Tracked in Biotics: Yes

SWAP 2015 Species of Greatest Conservation Need (SGCN): No

SWAP 2025 Species of Greatest Conservation Need (SGCN): Yes

2025 SGCN Priority Tier: High Conservation Concern

Element Occurrences (EOs) in Georgia: 2

Habitat Summary for element in Georgia: Sandridges

Description

Perennial herb with 1 - 3 slender, hairy, erect stems 1 - 2 feet (30 - 60 cm) tall. The leaves are simple, 1 - 3 inches (3 - 8 cm) long and less than 0.2 inch (5 mm) wide at the base, tapering to a pointed tip, with a conspicuous midvein; upper leaf surfaces have dark gland dots, lower leaf surfaces are hairy. The lower leaves have leaf stalks up to 2 inches (5 cm) long; the upper leaves have very short or no stalks; a pair of pointed stipules about 0.2 inch (4 - 8 mm) long are attached to the base of each leaf stalk. Flower clusters are up to 2 inches (2 - 5 cm) long, compact, on a stalk rising from the angle of leaf and stem. Flowers are less than 0.3 inch (8 mm) long, purple or dark blue, typically pea flower-shaped with an erect banner petal. Fruits are small, one-seeded pods with a bumpy, ridged surface and a short beak.

Similar Species

Lupine Scurf-pea (Orbexilum lupinellum) occurs throughout Georgia’s Coastal Plain; it has similar flowers but its leaves are palmately compound, with 3 - 7 extremely narrow leaflets radiating from a single point.

Related Rare Species

None in Georgia.

Habitat

Dry to moist Longleaf Pine-Wiregrass savannas and flatwoods.

Life History

Nothing is known about the reproductive biology of this extremely rare plant. As with most pea-type flowers, Pineland Scurfpea is probably pollinated by bees and the seeds are probably dispersed by small animals.

Survey Recommendations

Surveys are best conducted during flowering (May–June). These plants are very hard to spot amongst other flatwoods vegetation.

Range

Georgia and northeast Florida.

Threats

Fire suppression and conversion of habitat to pine plantations.

SWAP 2025 Threat Matrix

Threat 1 Threat 2 Threat 3

General Threat Agriculture & aquaculture Transportation & service corridors Residential & commercial development

Specific Threat None None None

	Threat 1	Threat 2	Threat 3
General Threat	Agriculture & aquaculture	Transportation & service corridors	Residential & commercial development
Specific Threat	None	None	None

Georgia Conservation Status

Orbexilum virgatum is ranked SH by the Georgia Department of Natural Resources, indicating that it has not been seen in Georgia in several decades. Two populations were documented in southeast Georgia in the 1930s, but neither have been confirmed since then.

Conservation Management Recommendations

Apply prescribed fire to pine flatwoods every 2 - 3 years during the growing season. Avoid clearcutting, bedding, plowing fire breaks, and other mechanical disturbances. Conduct flowering-season surveys in southeast Georgia to determine current status.

SWAP 2025 Conservation Actions:

Action 1: Complete a distributional survey to assess current range, conservation status or to identify best populations
Action 2: Improve habitat using prescribed fire
Action 3: Develop and implement a plan to reintroduce or augment specific populations
Action 4: Reassess the conservation status of SGCN before the next revision of Georgia's State Wildlife Action Plan

References

Chafin, L.G. 2007. Field guide to the rare plants of Georgia. State Botanical Garden of Georgia and University of Georgia Press, Athens.

GADNR. 2020. Element occurrence records for Orbexilum virgatum. Georgia Department of Natural Resources, Wildlife Resources Division, Social Circle, Georgia.

Godfrey, R.K. and J.W. Wooten. 1981. Aquatic and wetland plants of southeastern United States, Vol. 2, dicotyledons. University of Georgia Press, Athens.

Isely, D. 1990. Vascular flora of the southeastern United States, Vol. 3, Part 2, Leguminosae (Fabaceae). University of North Carolina Press, Chapel Hill.

NatureServe. 2019. Orbexilum virgatum comprehensive report. NatureServe Explorer. Arlington, Virginia. http://explorer.natureserve.org/servlet/NatureServe?searchName= Orbexilum+virgatum

Nelson, G. 2006. Atlantic Coastal Plain wildflowers. Globe Pequot Press, Guilford, Connecticut.

Turner, B.L. 2008. Revision of the Genus Orbexilum (Fabaceae: Psoraleeae). Lundellia, 2008(11): 1-7. https://bioone.org/journals/Lundellia/volume-2008/issue-11/1097-993X-1.11.1/Revision-of-the-Genus-Orbexilum-Fabaceae-Psoraleeae/10.25224/1097-993X-1.11.1.short

Weakley, A.S. 2015. Flora of the southern and mid-Atlantic States. University of North Carolina Herbarium, University of North Carolina, Chapel Hill. http://www.herbarium.unc.edu/flora.htm

Authors of Account

Linda G. Chafin

Date Compiled or Updated

L. Chafin, Jul. 2008: original account

K. Owers, Feb. 2010: added pictures

L. Chafin, Mar. 2020: updated original account

Orbexilum virgatum, illustration by Jean C. Putnam Hancock. Image may be subject to copyright.

Orbexilum virgatum, flowers, fruits (see base of flower cluster), leaf, and stem by Anne Barkdoll, courtesy of Atlas of Florida Plants, http://florida.plantatlas.usf.edu/ Image may be subject to copyright.