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Carex acidicola Naczi
Acid-loving Sedge
Federal Protection: No US federal protection
State Protection: No Georgia state protection
Global Rank: G2G3
State Rank: S2?
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: 5
Habitat Summary for element in Georgia: Granite outcrop woodlands
Perennial, grass-like herb forming dense clumps of several plants connected by very short rhizomes. There are no old, fibrous leaf sheaths persisting at the base of the plant. Flowering stems are 4.3 - 16 inches (11 - 41 cm) tall, three-angled in cross-section, and leafy; their bases are purple-red (not brown or green) for 1.25 - 3 inches (3.2 - 7.4 cm) above the ground. Vegetative stems are 10 - 17 inches (26 - 42 cm) tall, a little shorter than, or up to 1.3 times as tall as, the flowering stems. The stem leaves are less than 0.25 inch (3.7-5.5 mm) wide, M-shaped in cross-section, the upper surface with two prominent lateral veins and a less conspicuous midvein; surfaces are smooth and dark green, except that the bases of the lowest stem leaves are whitish between dark green veins. Each flowering stem is topped by an inflorescence consisting of an erect, narrow, staminate (male, pollen-bearing) spike 0.5 - 2 inches (12 - 49 mm) long held at the top of the stem and 2 - 5 erect pistillate (female, fruit-bearing) spikes further down along the stem. Pistillate spikes consist of 2 - 11, heavily veined, yellow-brown to dark brown (when mature), narrowly oval sacs (perigynia), each sac tightly enclosing a tiny (3.2 mm long), 3-sided fruit (an achene). Beneath each perigynium there is a pale, papery, oval scale, a little shorter than the perigynium and with a midvein extending into a bristle at the tip.
Distinguishing among species of Carex usually requires some technical expertise and at least 10x magnification. Acid-loving Sedge can be fairly well distinguished in the field by a combination of these features: moist woodland habitat, reddish-purple stem bases, whitish tissue at the very base of the leaves, perigynia tightly enveloping the achene (i.e. not inflated), and female and male spikes held in separate spikes with the male spike at the top of the stem. Identification should be confirmed with reference to a technical manual or herbarium specimens.
Forty-five species of Carex are rare in Georgia, see: https://georgiabiodiversity.org/portal/element_lists?group=plant
Detailed information about these 10 rare Carex species is provided on this website:
Acid-Loving Sedge (C. acidicola): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=34933
Baltzell's Sedge (C. baltzellii): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=15974
Granite Dome Sedge (C. biltmoreana): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=19146
Lime-fleeing Sedge (C. calcifugens): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=33655
Velvet Sedge (C. dasycarpa): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=15939
Cypress-knee Sedge (C. decomposita): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=21206
Meager Sedge (C. exilis): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=34936
Wretched Sedge (C. misera): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=16740
Radford’s Sedge (C. radfordii): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=15374
Roan Mountain Sedge (C. roanensis): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=21034
Thorne's Sedge (C. thornei): https://georgiabiodiversity.org/portal/profile?group=plants&es_id=34939
Lightly shaded, dry to moist woodlands and bottomland forests with acidic, sandy loam soils.
Carex acidicola is a perennial, winter-deciduous herb that reproduces by seed. It flowers and sets fruit in the spring. Like most sedges, it is wind-pollinated. Its small seeds are likely eaten by birds and other small vertebrates.
Surveys are best conducted during flowering and fruiting (April–May) although the plants may be identifiable later in the season by the reddish-purple stem bases and whitish leaf bases. Associated species include Painted Buckeye (Aesculus sylvatica), hickories (Carya spp.), Redbud (Cercis canadensis), Wild Ginger (Hexastylis arifolia), Eastern Red Cedar (Juniperus virginiana), and Hop Hornbeam (Ostrya virginiana).
Carex acidicola occurs in three widely separated areas: central Alabama, east-central Georgia, and near the Chattahoochee River in eastern Alabama and southwestern Georgia. It has been documented at fewer than a dozen sites range-wide, most of these in private ownership.
Carex acidicola is threatened by commercial and residential development, logging, conversion of habitat to pine plantations, and recreational vehicle traffic. As an inconspicuous sedge, it is likely to be overlooked or misidentified during surveys, leading to unintentional destruction.
| Threat 1 | Threat 2 | Threat 3 | |
|---|---|---|---|
| General Threat | Natural system modifications | Invasive & other problematic species, genes & diseases | Pollution |
| Specific Threat | None | None | None |
Carex acidicola is ranked S2? by the Georgia Department of Natural Resources, indicating that it is imperiled in the state but that there is not sufficient information about the species to assign a definitive rank. It is known from four sites in Georgia: two on conservation land and two on privately owned land.
Protect mature hardwood forests and hammocks from conversion to commercial and residential development and pine plantations. Protect known populations from recreational vehicle traffic. Include species as targets during surveys of mature upland and bottomland forests.
Ball, P.W. and A.A. Reznicek. 2003. Species account for Carex acidicola. Flora of North America North of Mexico, vol. 23. Accessed 1 August 2019. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357018
Naczi, R.F.C., C.T. Bryson, and T.S. Cochrane. 2002. Seven new species and one new combination in Carex (Cyperaceae) from North America. Novon 12: 508-532. https://www.jstor.org/stable/3393132?seq=1#metadata_info_tab_contents
NatureServe. 2019. Species account for Carex acidicola. NatureServe Explorer: an online encyclopedia of life, Version 7.1. NatureServe, Arlington, Virginia. Accessed 31 July 2019. http://explorer.natureserve.org/servlet/NatureServe?searchName=Platanthera+blephariglottis
SERNEC. Carex acidicola specimens. Southeast Regional Network of Expertise and Collections. Accessed 1 August 2019. http://sernecportal.org/portal/collections/index.php
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
Linda G. Chafin, 3 August 2019: original account.
