Cardamine L. (Brassicaceae)

Cardamine (Brassicaceae) is represented by seventeen species in North Carolina. Only Cardamine micranthera is listed at the federal level (Fed E, S1 G2). Two species are additionally state listed: C. dissecta (State SC-V, S2 G4?) and C. longii (State SC-V, S2 G3?). Cardamine douglassii (State SR-P, S2 G5) and C. rotundifolia (State SR-P, S2 G4) were delisted at the state level in 2021, but remain of conservation concern and are tracked by NHP along with C. clematitis (State SR-T, S2S3 G3).

Federally listed taxon—
Cardamine micranthera (Fed E, State E | S1 G2)

Habitat. Creek and stream banks, seepages, wet rock crevices in the Dan River drainage.

Range. Endemic to North Carolina and Virginia.

Additional resources. NHP | Recovery plan | 5-yr review

Key to Cardamine in North Carolina

Key adapted from Weakley (2008) and Al-Shebaz et al. (2010). Photos by Krings, unless otherwise indicated. Line drawings from Britton & Brown (1913), unless otherwise indicated. Maps courtesy of USDA PLANTS and the North Carolina Natural Heritage Program.

1. Leaves palmately divided...2.

2. Leaflets highly dissected with linear to filiform segments, basal leaves similar to cauline leaves, cauline leaves alternate or subopposite; plants typically entirely glabrous (including leaf margins), rarely with very few and very scattered trichomes...C. dissecta

2’. Leaflets not highly dissected into linear or filiform segments (sometimes narrow in C. concatenata, but then cauline leaves usually oppposite or whorled), basal leaves not similar to cauline leaves (C. angustata) or similar (C. diphylla, C. concatenata), cauline leaves usually alternate (C. angustata), or whorled or opposite (C. diphylla, C. concatenata); plants with at least leaf marginal trichomes, often also pubescent elsewhere...[C. angustata, C. concactenata, C. diphylla]

1’. Leaves simple, pinnately lobed, or pinnately divided...3.

3. Cauline leaves simple, sometimes the lower to middle cauline leaves with 1–2 pairs of very small lateral lobes...4.

4. Plant from a tuberous or bulbous base, erect and generally unbranched, not stoloniferous or rooting from upper nodes after flowering...5.

5. Stems glabrous or if distally pubescent, then trichomes ≤ 0.1 mm long; petals white (rarely pink); cauline leaves 4–12...C. bulbosa

5’. Stems pubescent at least distally (sometimes glabrous proximally), trichomes ≥ 0.3 mm; petals pink or lavender (rarely white); cauline leaves 2–5...C. douglassii

4’. Plant from a fibrous root system, frequently much branched from the base, some of the branches becoming stoloniferous and rooting at the upper nodes after flowering...6.

6. Petals absent or if present, 0.7–2 mm long; silique 5–10 (–15) mm long, plus a 0.5–1.0 mm beak; pedicels thick, 1–3 (–6) mm long; CP...C. longii

6’. Petals present, 2–10 mm long; silique 8–21 mm long, plus a 1–3 mm beak; pedicels slender, 10–20 mm long; Pd and Mt...7.

7. Petals 3–5 mm long, apices ascending or erect; anthers ovate to orbicular, ca. 0.2 mm long; ovules 16–22 per ovary; lower and mid-cauline leaves (or terminal leaflets) cuneate, rounded, or truncate (rarely subcordate)...C. micranthera*

7'. Petals 5–10 mm long, apices spreading or ascending; anthers oblong, 0.8–1.2 mm long; ovules 40–80 per ovary; lower and mid-cauline leaves (or terminal leaflets) often cordate...C. rotundifolia

3’. Cauline leaves 1-ternate or pinnatifid...8.

8. Cauline leaves with 3–5 leaflets; petals 4–10 mm long; plant a perennial...9.

9. Stem glabrous at base; abaxial surface of lower leaves green; petiole auricles 1–5 mm long, acute to acuminate; siliques 22–40 mm long...C. clematitis

9’. Stem pubescent at base; abaxial surface of lower leaves purple; petioles not auriculate at the base; siliques 10–25 mm long...C. flagellifera

8’. Cauline leaves with 7–numerous leaflets; petals 1–4 mm long or absent; plant an annual, biennial, or perennial...[C. debilis, C. flexuosa, C. hirsuta, C. impatiens, C. parviflora, C. pensylvanica]