walking fern

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An eastern North American evergreen fern (Asplenium rhizophyllum) having undivided fronds that often take root at the tip.

from The Century Dictionary.

• noun A small tufted evergreen fern, Camptosorus rhizophyllus, native of eastern North America, having the fronds heart-shaped or hastate at the base, and tapering above into a slender prolongation, which frequently takes root at the apex (whence the name;). Also walking-leaf.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Either of two species of fern in the genus Asplenium (Asplenium rhizophyllum or Asplenium sibiricum) that produces new plantlets from the tips of its leaves.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun ferns having lanceolate fronds that root at the tip