Carex L. (Cyperaceae)

Carex (Cyperaceae) is represented by over 150 species in North Carolina. A number of species are of conservation concern, state listed or proposed for listing, but only Carex lutea is currently federally listed (Fed E, S2 G2). Those listed or proposed for listing as endangered at the state level include: C. aryrantha (State E, S1 G5), C. cherokeensis (State E, S1 G4G5), C. exilis (State E, S2 G5), C. oligosperma (State E, S1 G5?), C. tenax (State E, S1 G5?), and C. trisperma (State E, S1 G5).

Federally listed taxon—
Carex lutea (Fed E, State E | S2 G2)

Habitat. Ecotone between pine savanna and adjacent wet hardwood (often with Taxodium ascendens and Thalictrum cooleyi) in mildly acidic to circumneutral, wet to periodically inundated, sandy soils, frequently over coquina limestone.

Range. Endemic to the southeastern North Carolina Coastal Plain.

Additional resources. NHP | USFWS | Recovery plan

Key to Carex lutea

Key adapted from LeBlond et al. (1994 [protologue, Sida]), Ball and Reznicek (2002 [FNA]), Crins (2002 [FNA]), and Weakley (2008). Photos by Krings, unless otherwise indicated. Line drawings from LeBlond et al. (1994). Maps courtesy of USDA PLANTS and the North Carolina Natural Heritage Program.

1. Perigynium beak teeth ≥ 0.5 mm long...[various spp.]

1’. Periynium beak teeth typically < 0.5 mm long...2.

2. Perigynia minutely papillose...[various spp.]

2’. Perigynia smooth...3.

3. Terminal spike gynecandrous (i.e., pistillate flowers borne above the staminate in the same spike)...[various spp.]

3’. Terminal spike staminate or androgynous (i.e., staminate flowers borne above the pistillate in the same spike)...4.

4. Sheaths and blades pubescent...[various spp.]

4’. Sheaths and blades glabrous...5.

5. Bracts without blades...[various spp.]

5’. Bracts with blades...6.

6. Style persistent...[various spp.]

6’. Style deciduous...7.

7. Young leaf blades (at least the widest) M-shaped in cross-section, adaxial surface with two marginal veins more prominent than the midvein...[various spp.]

7’. Young leaf blades V-shaped in cross-section; adaxial surface lacking two marginal veins more prominent than the midvein...8.

8. Proximal perigynia (lowermost on spike) ascending or spreading-ascending at maturity...[various spp.]

8’. Proximal perigynia in each spike reflexed at maturity...C. lutea*