Lygodium flexuosum

Name and classification

Lygodium flexuosum (L.) Sw.
(=Ophioglossum flexuosum L.)
Family Lygodiaceae, Tribe Paniceae

Common names

maidenhair creeper

Disseminule

spores, rhizomes

Description

Rhizomatous perennial fern, with climbing rachis up to 2.5 mm thick, slightly pubescent, subterete, flattened on one side, narrowly winged or tetragonous. Primary rachis branches 2–16 mm long. Secondary pinnae narrowly ovate to oblong or rarely palmate, 7–30 cm long, 4.5–12 cm wide, 1–2-pinnate. Stalks of the leaflets (pinnules) are shorter in length towards pinna apex. Ultimate pinnules are 1.5–10 cm long, 5–16 mm wide; sterile ones sometimes fused basally and palmately-lobed, membranous, glabrous or sparsely pubescent; base truncate; margins serrulate; veins free. Fertile pinnules similar in length or shorter than sterile ones. Sporogenous lobes 1.5–8 mm long. Spores finely verrucose.

Identification considerations

Pinnule leaflet stalks that become shorter in length towards pinna apex distinguish this species from Lygodium microphyllum. Fronds are typically 2-pinnate in L. flexuosum versus 3-pinnate in L. japonicum.

Similar species

Lygodium japonicum (Thunb. ex. Murr.) Sw. (non-FNW)

Lygodium microphyllum (Cav.) R. Br.

Distribution

southeastern Asia southward to Australia; not currently known to occur in the U.S.

Habitat

climbs trees and scrambles in open places in deciduous or mixed forests

General information

Lygodium flexuosum is widespread in eastern Asia, adversely affecting rice crops and natural lowland vegetation. It has confirmed medicinal properties.

sterile leaflets; www.flickr.com/photos/flowerfreak/ CC BY-NC-ND 2.0

sterile leaflets; www.flickr.com/photos/flowerfreak/ CC BY-NC-ND 2.0

fertile leaflets; www.flickr.com/photos/tony_rodd/ CC BY-NC-SA 2.0

fertile leaflets; www.flickr.com/photos/tony_rodd/ CC BY-NC-SA 2.0