Lecanopteris

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Lecanopteris

Description

Epiphytic, very rarely epilithic, ant-inhabited ferns.

Distribution

Asia-Tropical:
Southern Indochina; throughout Malesia.

Taxonomy

Two subgenera are distinguished (Hennipman in Gay et al. 1994): Subgenus Lecanopteris: rhizome with inconspicuous, deciduous, deltoid scales, oth-erwise often with dense short glandular hairs, conspicuous spines or other large outgrowths; sori immersed on the lamina or in marginal lobes. All species have very con-spicuously thickened, hollow rhizomes, often forming large clumps or balls around the branches of the host tree. The presence of sori on the lamina in two species (L. spinosa and L. balgooyi) indicates affinity with the previous subgenus, otherwise this is a very distinct group. The rhizome is usually green or glaucous when young, and blackening with age. In several species it is covered with strong spines. Sometimes these clearly represent modified fronds, set in two rows on the dorsal side of the rhizome; in other species they are much more densely set. The coralloid outgrowths present in L. carnosa are clearly derived from frond primordia.

Subgenus Myrmecopteris: rhizome with conspicuous, persistent, orbicular, peltate scales, otherwise glabrous; sori immersed on the lamina; L. mirabilis, L. lomarioides, L. crustacea and L. sinuosa. Lecanopteris mirabilis has flattened rhizomes, the other species have more or less strongly thickened and hollow rhizomes. This subgenus has been given generic rank by Pichi Sermolli (1977). It is included in Phymatodes (= Microsorum) by Holttum (1954), to which it obviously is closely allied, with L. sinuosa, possessing relatively thin rhizomes, most nearly occupying an intermediate position.

Notes

1 Habitat and distributional data for all species are mainly compiled from Gay et al. (1994). 2. All species are myrmecophytes. The ecological aspects of the fern-ant association are described in Gay et al. (1994, and references therein). The association is mutualistic, the plants providing shelter for the ants, the ants providing nutrients for the plants. It is not an evolutionary, historical constrained association: the species of ants inhabiting a particular species of Lecanopteris are replaced by other species whenever the distribution of a fern species is wider than that of an inhabiting ant. The surprisingly high number of endemic species in Sulawesi is so far not explained.

Citation

Holttum - in Rev. Fl. Malaya. 1954: 208
Hennipman - in Kew Bull. 1986: 783
H.E. Gay et al. - in Gard. Bull. Sing. '1993’, 1994: 295
Hennipman et al. - in Kramer & Green, Fam. & Genera Vasc. Pl. 1. 1990: 217
Copel., Gen. Fil. 1947: 205
Hennipman & Verduyn - in Blumea. 1987: 313