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Boston swordfern, sword fern, wild Boston fern

Boston fern, narrow swordfern, sword fern, tuber ladder fern, tuber sword fern, tuberous sword fern


scales spreading, concolored.

scales spreading, concolored.


4–15 × 0.5–1.2 dm.

2.5–10.7 × 0.3–0.7 dm.


0.2–4 dm, sparsely to moderately scaly;

scales spreading, pale brown to reddish brown, concolored.

0.3–2 dm, moderately to densely scaly;

scales spreading, pale brown throughout.


glabrous, sparsely to moderately scaly abaxially near costae and adaxially.

lacking scales, glabrous (rarely with a few branched hairs abaxially).


reniform to horseshoe-shaped, attached at narrow or broad sinus, 1–1.7 mm wide.

reniform to lunate or deltate-rounded, attached along broad sinus, 1.1–1.7 mm wide.



present or absent.


2.4–16.3 dm, points of pinna attachment 7.3–21 mm apart;

scales moderately spaced, pale to dark brown, essentially concolored or margin indistinctly paler;

hairs absent.

2.2–9 dm, points of pinna attachment 5–12 mm apart;

scales moderately spaced to dense, pale to dark brown, point of attachment distinctly darker.


pinnae deltate-oblong, slightly to distinctly falcate, 2.3–7.4 × 0.6–1.8 cm, base truncate to truncate-auriculate or auriculate, occasionally overlapping rachis, acroscopic lobe deltate to acute, margins serrulate, apex acute to deltate;

costae adaxially glabrous.

pinnae oblong to lanceolate-oblong, straight to slightly falcate, 0.9–5 × 0.4–0.9 cm, base auriculate-cordate, acroscopically overlapping rachis, acroscopic lobe deltate, margins entire to serrulate to smoothly crenate, apex acute to bluntly rounded;

costae adaxially glabrous.


= 82.

Nephrolepis exaltata

Nephrolepis cordifolia

Habitat Terrestrial or epiphytic in forested to open habitats, most often as an epiphyte Terrestrial or epiphytic in wet, shady places, limestone ledges, cliffs, rock, roadsides, and often old homesites or waste places, widely escaped from cultivation and only questionably native to any particular region
Elevation 0 m (0 ft) 0 m (0 ft)
from FNA
FL; West Indies; Pacific Islands in scattered locations
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from FNA
FL; HI; Mexico; Central America; South America; West Indies; Africa; se Asia
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Nephrolepis exaltata is occasionally found farther north in the flora, but only as an escape from cultivation. Nephrolepis exaltata is usually confused with N. cordifolia when sterile; the latter species can be distinguished by its distinctly bicolored, adaxial rachis scales. These bicolored scales will distinguish N. cordifolia from all of the other species, even in the absence of other key features.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 2. FNA vol. 2.
Parent taxa Dryopteridaceae > Nephrolepis Dryopteridaceae > Nephrolepis
Sibling taxa
N. biserrata, N. cordifolia, N. multiflora, N. ×averyi
N. biserrata, N. exaltata, N. multiflora, N. ×averyi
Synonyms Polypodium exaltatum Polypodium cordifolium, Aspidium cordifolium
Name authority (Linnaeus) Schott: Gen. Fil. plate 3. (1834) (Linnaeus) C. Presl: Tent. Pterid. 79. (1836)
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