Australian ferns & fern allies
Australian National Botanic Gardens
Australian National Herbarium

Platyzomataceae

Terrestrial ferns with a short-creeing dorsiventral rhizome, bearing unbranched uniseriate hairs; vasculature a medullated protostele. Fronds clustered or tufted, dimorphic, some filiform and undivided, others long, linear and pinnate with rouned bullate pinnules with strongly revolute margins forming a pouch-like cavity, yellowish waxy powder beneath; stipe dark, glossy, glabrescent. Anisosporus, sporangia borne singly at tips of veins, containing either c. 16 larger or c. c. 32 smaller spores (sometimes intermediates), exindusiate, leaflets fertile in zones in the distal half of the frond. Spores of two not vastly different sizes, one type aproximately twice the size of the other with some intermediates, trilete, globose to tetrahedral, some monolete or bilateral, perispore lacking.

Distribution

A monotypic family restricted to northern Australia in sandy or swampy soils, sometimes subject to periodic flooding.

Literature

Genera

Note

A family for a long time placed with Gleicheniaceae, due to the remarkable similarity of the linear frond segments with close rounded bullate pinnae of Platyzoma with some species of Gleichenia. Modern authors are chosing to place Platyzoma in its own family with affinities to the gymnogrammoid ferns of Adiantaceae sens. lat.

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Updated November 1999 by Jim Croft (jrc@anbg.gov.au)

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