Sword fern

Nephrolepis exaltata -- Center for Aquatic and Invasive Plants

Nephrolepis exaltata

Native to Florida

For more information, read this UF/IFAS-EDIS publication
Natural Areas Weeds: Distinguishing Native and Non-Native "Boston Ferns" and "Sword Ferns" (Nephrolepis spp.) by K.A. Langeland.

Nephrolepis exaltata is commonly found in swamps and wet hammocks throughout the central and southern peninsula. Sword fern also grows in Suwannee, Duval and Leon counties (Wunderlin, 2003).

Identification

The fronds of Nephrolepis exaltata grow to 1.5 meters tall. The petiole is sparse to moderate, with pale to reddish-brown scales of a single color or is slightly darkened at the attachment, with an expanded base bearing small marginal hairs. The rachis has hairlike scales of one color that have expanded bases bearing small, marginal hairs. The pinnae are 7.4 cm long, 1.8 cm wide and attached .7 to 2.1 cm apart. Bases usually are not overlapping the rachis. The pinnae are slightly curving to decidedly sickle-shaped near the apex with acute to attenuate tips. The basal lobe on the upward facing edge sometimes overlaps the rachis. It is sparsely to moderately scaly near the midvein and base with pale brown scales. Lastly, the indusia are rounded to horseshoe-shaped.

Tuberous sword fern (Nephrolepis cordifolia) and Asian sword fern (Nephrolepis multiflora) are similar in appearance to the native sword fern and giant sword fern. Tuberous sword fern is sold under various names (e.g. Boston fern, hardy fern, large fern, erect sword fern) and names are often interchanged among the different species. Tuberous sword fern is most often confused with and sold in some stores as the native sword fern (Langeland, 2001).