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Dennstaedtiaceae

Incl. Hypolepidaceae

Small to large terrestrial ferns (very rarely with a climbing rhizome), the rhizome wide-creeping underground, branching dichotomously or sympodially with fronds arising from the branches, less often erect and radial, solenostelic or dictyostelic, tips with simple hairs, less often pluricellular hairs, rarely with dark, non-clathrate, non-peltate scales. Fronds long-stipitate, sometimes scrambling, the stipes not articulate to the rhizome, vascular tissue mostly U-shaped, lamina mostly pinnately decompound and finely divided, less often 1 - 2-pinnate, veins free simple or 1 - several times forked, less often anastomosing without free included veinlets; little, if any, sterile/fertile dimorphism. Sori terminal on the veins, small and round or elongate and spreading along a vascular commisure uniting the vein endings, often indusiate, the indusium opening towards the margin, sometimes cup-shaped, or 2-valved with the reflexed leaf margin (sometimes scariose) forming a false indusium, sometimes the true and/or false indusium absent, annulus longitudinal, interrupted, stalk slender and 2-seriate, paraphyses present or absent; spores trilete, tetrahedral, sometimes monolete, lacking a perispore.

Distribution

A family of 13 genera and about 200 species, widespread but more common in the old world and in the southern hemisphere. In Papuasia there are 8 genera with about 40 species.

Literature

Copeland, E.B. 1949. Pteridaceae of New Guinea. Philip. J. Sci. 78: 5 - 40.

Genera

1a.

Sori in cup-like indusia at the ends of veins, marginal in the sinuses

2

Sori infra-marginal at the ends of veins, indusia not fully cup-like, or lacking, or sori protected by reflexed lobes of lamina

3

2a.

Rhizome slender, creeping, hairy

Dennstaedtia (c. 12)

Rhizome stout, erect, scaly

Orthiopteris (c. 5)

3a.

Sori continuous or +/- elongate along edges of lamina

4

Sori singly at the ends of the veins

6

4a.

Veins anastomosing; sori protected by the reflexed margin of the lamina only, inner indusium lacking; rhizome with scales and hairs

Histiopteris (c. 4)

Veins free, except in the sorus; sori protected by an inner indusium and the reflexed margin; rhizome with hairs only

5

5a.

Rachis usually zig-zag; fertile pinnules often wider and less dissected than sterile; spores monolete

Paesia (1)

Rachis straight; fertile pinnules not different from sterile; spores trilete

Pteridium (2)

6a.

Indusium pocket-shaped, attached at the base and part of the sides

Microlepia (c 6)

Indusium free at the sides or lacking

7

7a.

Indusium lacking, sorus mostly protected by a reflexed tooth of the lamina

Hypolepis (c. 6)

Indusium present, attached by one point to the vein beneath the sorus

8

8a.

Frond hairy; rhizome short-creeping

Oenotrichia (? 1)

Frond glabrous; rhizome long-creeping

Leptolepia (1)

Note

Leptolepia has been only once reported from Papuasia and the record may be based on a misidentification.

In some treatments Dennstaedtiaceae is considered in a very broad sense to include several other families, such as the Lindsaeaceae, and sometimes it is included within an equally broad Pteridaceae.

Often the rare genus Monachosorum (Monachosoraceae) is included in this family, but the glandular sori and mucilage-secreting rhizomes are anomalous.

Some authors feel that those genera with marginal +/- elongate sori +/- protected by a reflexed edge of the lamina (Pteridium, Paesia, Histiopteris, Hypolepis etc.) should be allocated their own segregate family, the Hypolepidaceae.


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