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Euphorbia georgiana Mayfield
Georgia Spurge
Federal Protection: No US federal protection
State Protection: No Georgia state protection
Global Rank: G1?
State Rank: S1?
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: Highest Conservation Concern
Element Occurrences (EOs) in Georgia: 4
Habitat Summary for element in Georgia: Granite outcrops
Annual herb with 1 - 3 erect, hairless stems 4 - 7 inches (10 - 18 cm) tall rising from the base of the plant. Stem leaves are 0.2 - 0.5 inch long and less than 0.2 inch wide (0.5 - 1.2 cm long, 0.3 - 0.5 cm wide at the widest point), alternate, angled upwards, widest above the middle, hairless, with a conspicuous midvein, tapering bases, and rounded tips. Leaves at the base of the branched flower cluster are 3 in number, up to 0.4 inch long and 0.3 inch wide (0.9 - 1.1 cm long, 0.5 - 0.7 cm wide), round or oval. Leaves within the flower cluster are up to 0.24 inch (0.3 – 0.6 cm) long, triangular to kidney-shaped with rounded or blunt tips. The flower cluster consists of 3 slender stalks (“rays”) that branch 2 - 4 times; each ultimate branch is tipped by two rounded, leaf-like bracts and a type of inflorescence called a cyathium. In the cyathium, there are 4 tiny, greenish, crescent-shaped glands; 5 - 10 male flowers, each consisting of only a single stamen; and a single female flower consisting of a drooping, three-lobed ovary with 3 bisected styles. These female and male flowers are so closely arranged that they appear to be one bisexual flower. The ovary develops into a three-segmented, oval capsule about 0.1 inch (0.3 cm) wide, held on a tiny, drooping stalk. Each segment of the capsule contains one gray, oval seed with deep, black, rounded pits scattered over the entire surface. All parts of the plant ooze a milky latex when cut or broken.
There are more than 20 species of Euphorbia in Georgia; Georgia Spurge is the only species known to occur on granitic outcrops. Georgia Spurge most closely resembles Woodland Spurge (Euphorbia commutata), which occurs in moist forests over calcareous bedrock and has never been seen on granite outcrops. Woodland Spurge is a biannual 8 - 16 inches (20 - 40 cm) tall. Flowering Spurge (Euphorbia corollata) and Southeastern Flowering Spurge (E. pubentissima) may occur in dry woodlands surrounding outcrops. They have (relatively) showy, white, petal-like glands surrounding the cyathia.
Florida Spurge (Euphorbia floridana, Georgia Special Concern) occurs in sandhill and xeric scrub in southeast Georgia. For more information, see: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250101650
Flatwoods Spurge (Euphorbia inundata var. inundata, Georgia Special Concern) occurs in pine flatwoods and on streambanks in Georgia’s Coastal Plain. For more information, see: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250101652
Carolina Ipecac (Euphorbia ipecacuanhae, Georgia Special Concern) occurs in xeric sandhills in Georgia’s Coastal Plain. For more information, see: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250101539
Euphorbia purpurea (Glade Spurge, Georgia Special Concern) occurs in wet seeps over amphibolite in Georgia’s Blue Ridge. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=34049
Piedmont granite outcrops
Georgia Spurge is an annual herb that reproduces only by seed. Nothing has been published on the life history of this newly (2013) described species but life history information for related Euphorbia species may apply. As a summer annual, Georgia Spurge seeds germinate in the early spring and flower in April and May. As described above, Georgia Spurge plants are monoecious, i.e. female and male flowers are in separate structures on the same plant – the flowers probably mature at different times to prevent self-pollination. Most Euphorbia species are pollinated by insects that are attracted to nectar produced in glands on or around the cyathium whose flowers mature in the spring. Seed dispersal takes place in early summer, after which the plants begin to senesce. Seeds are dispersed explosively from the capsule: the walls separating the three lobes of the fruit dry out and contract, suddenly splitting open with a loud pop and propelling seeds several feet from the parent plant.
Surveys should be conducted in the spring during flowering and fruiting. The plants likely wither and die soon after seed dispersal.
Euphorbia georgiana is believed to be endemic to Georgia. However, surveys of Piedmont granite outcrops in other southern states may discover new populations.
Georgia’s Piedmont granite outcrops are threatened by quarrying, trash dumping, off-road vehicle traffic, mulching, trampling, and clearing.
| Threat 1 | Threat 2 | Threat 3 | |
|---|---|---|---|
| General Threat | Energy production & mining | Human intrusions & disturbance | Transportation & service corridors |
| Specific Threat | None | None | None |
Euphorbia georgiana is ranked S1? by the Georgia Department of Natural Resources, indicating that it is probably critically imperiled but that additional field surveys are needed to confirm the status. There are 3 known populations, none on conservation land.
Protect granite outcrops from quarrying, trash dumping, and off-road vehicle use. Purchase granite outcrops for conservation. Create buffers and limit development around outcrops. Eradicate exotic pest plants. Map locations of plants and direct foot traffic away from populations.
GADNR. 2019. Element occurrence records for Euphorbia georgiana. Georgia Department of Natural Resources, Wildlife Resources Division. Social Circle, Georgia.
Mayfield, M.H. 2013. Four new annual species of Euphorbia Section Tithymalus (Euphorbiaceae) from North America. Journal of the Botanical Research Institute of Texas 7(2): 633-647.
Ricarda Riina, R., D.V. Geltman, J.A. Peirson, P.E. Berry.2016. Species account for Euphorbia georgiana. Flora of North America North of Mexico, vol. 12. Magnoliophyta: Vitaceae to Garryaceae. Oxford Univ. Press, New York. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250101633
NatureServe. 2019. Species account for Euphorbia georgiana. NatureServe Explorer: an online encyclopedia of life, Version 7.1. NatureServe, Arlington, Virginia. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.1048019/Euphorbia_georgiana
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
Linda G. Chafin
L. Chafin, April 2020: original account.