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Ophioglossaceae

Incl. Botrychiaceae, Helminthostachyaceae

Small to moderate-size, fleshy, terrestrial ferns or pendulous epiphytes, rhizome short, fleshy, erect or creeping, siphonostelic, sometimes dictyostelic, lacking scales or hairs, the frond subtended by a pair of fleshy stipule like outgrowths. Fronds stipitate, or the stalk short and decurrent into lamina, the lamina with separate sterile and fertile portions, vernation not circinnate; sterile segment (tropophore) simple, tripartite, pinnate or 2-3 pinnatifid, thin or fleshy, veins free to the margin, 1-3 forked, the ultimate segments costate or ecostate; the fertile segment stipitate, arising from the stipe, at or near the base of the tropophore or from the rachis of the tropophore, erect or pendulous, spike-like with crowded lateral branches or 2 rows of sporangia, or paniculate with up to 3 or more orders of branching. Sporangia large, thick-walled, superficial or imbedded within the sporangiophore, dehiscing by a transeverse slit, the annulus lacking, exindusiate; spores trilete, +/- smooth to densely papillose, punctate or finely reticulate.

Distribution

A family of 4 genera and C. 70 species from most of the moist tropical and temperate regions of the world. Three genera occur in Papuasia with c. 8 species.

Literature

Jermy, A.C. & Walker, T.G. 1977. A note on the cytology of Botrychium lanuginosum and the occurrence of the genus in Malesia. Gard. Bull. Sing. 30: 293 - 298.

Johns, R.J. 1981. The ferns and fern allies of Papua New Guinea. Part six: the Ophioglossaceae. P.N.G. Univ. Tech. Res. Rep. R 48-81: 6.1 - 6.26.

St. John, H. 1943. Distribution of Ophioglossum on the islands of the Pacific Ocean. Occ. Pap. Bish. Mus. 17: 177 - 182.

Weiffering, J.H 1964. A preliminary revision of the Indo-Pacific species of Ophioglossum (Ophioglossaceae). Blumea 12: 321 - 337.

Genera

1a.

Terrestrial or epiphytic; sporangia in 2 rows, imbedded in an almost terete spike; sterile segment simple, sometimes with a few broad lobes

Ophioglossum (c. 4)

Terrestrial; sporangia in branches of the fertile segment of the frond; sterile segment at least tripartite and lobed

2

2a.

Fertile segment of the frond compact with many short branches; sterile segment tripartite, each part with a few lobes or leaflets

Helminthostachys (1)

Fertile segment pinnately branched with many small divisions

Botrychium (3)

Note

Some authors prefer to divide the genus Ophioglossum further:

1a.

Terrestrial; apex of fertile segment with a short sterile tip, not fused to the sterile segment, or only at the base; sterile segment abruptly merging with the stipe

Ophioglossum (c. 3)

Epiphytic, subepiphytic, or less often terrestrial; fertile segment fertile to the tip, fused to the sterile segment; sterile segment gradually tapering into the stipe

Ophioderma (1)

In this treatment, this distinction is recognized, but at the subgeneric level.


Updated November 1999 by Jim Croft (jim.croft@environment.gov.au)