American Climbing Fern (Lygodium palmatum)
Climbing Fern family (Lygodiaceae)
American climbing fern is a climbing fern, climbing at least to 9 feet. The stem is thin and wiry. The fronds (leaves) can reach 9 feet long and around 5 in wide. Climbs by using the frond’s rachis (stalk). The fronds are divided into leaflets (pinnae), which are each divided into 2 subleaflets (pinnules). The sterile leaflets are broadly ovate and deeply palmately lobed (hand-shaped). Lobes oblong to triangular-elongate. Toward the top of the frond, the fertile leaflets are irregularly lobed or forked, ultimate divisions usually palmately lobed, narrower and smaller than the sterile fronds, and with narrowly triangular to linear-triangular ultimate lobes. The fertile leaflets release spores in the summer to early fall. In dry weather, the leaflet tips curl under. Found in the eastern United States, especially around the Cumberland Plateau and Appalachian, and Piedmont. It occurs on poorly-drained to moist acidic soils, especially after disturbance, and grows best in full sun, not tolerant of shade. The fronds were once gathered for Christmas decorations. Also known as Hartford fern, creeping fern, Thoreau’s climbing fern and Windsor fern. Sometimes placed in the Schizaeaceae family.
Listed as endangered in IN, MI, NY, and VT; threatened in MD; species of special concern in CT, MA, and RI; and rare in PA.
Copyright Brett Miley
