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American bittercress, mountain watercress

long's bitter-cress

Habit Perennials; glabrous throughout. Perennials; glabrous throughout.
Rhizomes

slender, to 2 mm diam.

cylindrical, slender, 0.8–1.5 mm diam.

Stems

usually procumbent, sometimes erect, (not flexuous), unbranched or branched, (1–)1.5–3(–5) dm.

prostrate to decumbent or erect, unbranched or branched, 0.5–4(–6) dm.

Basal leaves

(soon withered), not rosulate.

Rhizomal leaves

absent.

absent.

Cauline leaves

simple, petiolate;

petiole (0.3–)0.5–2.5(–4) cm, base not auriculate;

blade oblong, ovate, suborbicular, or cordate, (0.5–)1–4.5(–5.5) cm × (5–)10–40(–54) mm, base cordate, rounded, or truncate, margins entire, repand, or sinuate, (distally with shorter petiole, blade smaller).

3–10, usually simple, rarely 3 or 5-foliolate, petiolate;

petiolulate or sessile;

petiole 0.4–2.5 cm, base not auriculate;

lateral leaflets (when present) sessile or petiolulate (to 0.2 cm), blade similar to terminal, considerably smaller;

terminal leaflet blade orbicular to reniform or ovate to oblong, 0.4–3 cm × 3–20 mm, (somewhat fleshy), base subcordate to rounded or subtruncate, margins entire or repand, rarely undulate, (apex rounded).

Racemes

ebracteate.

ebracteate.

Flowers

sepals oblong, 2–3 × 1–1.7 mm, lateral pair not saccate basally;

petals white, broadly oblanceolate, spreading, 5–7(–8) × 2–3 mm, (not clawed, apex rounded);

filaments: median pairs 3.5–4.5 mm, lateral pair 2.7–3.5 mm;

anthers oblong, 0.8–1.2 mm.

sepals ovate, 0.7–1.2 × 0.5–0.7 mm, lateral pair not saccate basally;

petals absent or rudimentary, to 0.7 mm;

filaments 0.5–0.8 mm;

anthers ovate, 0.1–0.2 mm.

Fruiting pedicels

divaricate to ascending, (6–)10–15(–20) mm.

divaricate-ascending to spreading, 0.5–2(–4) mm.

Fruits

linear, (torulose), 1–1.5(–2) cm × 0.8–1.1 mm;

ovules 40–80 per ovary;

style 1.5–2.5 mm.

narrowly oblong to linear, (3–)5–10(–15) × 0.8–1.2 mm;

ovules 6–22 per ovary;

style 0.2–0.5(–1) mm.

Seeds

brown, oblong to ovoid, 0.9–1.1 × 0.5–0.6 mm.

light or yellowish brown, oblong or ovoid, 1–1.4 × 0.7–1 mm.

Cardamine rotundifolia

Cardamine longii

Phenology Flowering Apr–Jun. Flowering Jun–Sep.
Habitat Stream banks, swamps, low woodland, wet rocky areas, seepage areas Tidal marshes, mud flats, tidal shores of rivers, shallow water, swampy areas, shady rocky crevices covered at high tide
Elevation 150-400 m (500-1300 ft) 0-10 m (0-0 ft)
Distribution
from FNA
DE; GA; KY; MD; NC; NJ; NY; OH; PA; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; MA; MD; ME; NC; NJ; NY; SC; VA
[BONAP county map]
Source FNA vol. 7, p. 483. FNA vol. 7, p. 476.
Parent taxa Brassicaceae > tribe Cardamineae > Cardamine Brassicaceae > tribe Cardamineae > Cardamine
Sibling taxa
C. angulata, C. angustata, C. bellidifolia, C. blaisdellii, C. breweri, C. bulbosa, C. californica, C. clematitis, C. concatenata, C. constancei, C. cordifolia, C. digitata, C. diphylla, C. dissecta, C. douglassii, C. flagellifera, C. flexuosa, C. hirsuta, C. holmgrenii, C. impatiens, C. longii, C. macrocarpa, C. maxima, C. micranthera, C. microphylla, C. nuttallii, C. nymanii, C. occidentalis, C. oligosperma, C. pachystigma, C. parviflora, C. pattersonii, C. penduliflora, C. pensylvanica, C. pratensis, C. purpurea, C. rupicola, C. umbellata
C. angulata, C. angustata, C. bellidifolia, C. blaisdellii, C. breweri, C. bulbosa, C. californica, C. clematitis, C. concatenata, C. constancei, C. cordifolia, C. digitata, C. diphylla, C. dissecta, C. douglassii, C. flagellifera, C. flexuosa, C. hirsuta, C. holmgrenii, C. impatiens, C. macrocarpa, C. maxima, C. micranthera, C. microphylla, C. nuttallii, C. nymanii, C. occidentalis, C. oligosperma, C. pachystigma, C. parviflora, C. pattersonii, C. penduliflora, C. pensylvanica, C. pratensis, C. purpurea, C. rotundifolia, C. rupicola, C. umbellata
Synonyms Dentaria rotundifolia
Name authority Michaux: Fl. Bor.-Amer. 2: 30. (1803) Fernald: Rhodora 19: 91. (1917)
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