Polypodiophyta. The Polypodiaceae are mostly epiphytic or sometimes terrestrial ferns comprising about 50 genera and 550 mostly tropical species. The sporophyte consists of creeping rhizomes that give rise to simple, or less commonly, pinnate leaves. The rhizomes are covered with scales that are often peltate. The leaf axis and rhizome have several vascular bundles arranged in a circular pattern. The small, lens-shaped sporangia are usually long-stalked, and are borne in naked circular or continuous sori.
Each "thumbnail" image below is linked to a larger photograph.
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Phymatosorus scolopendrium, laua'e. This photo shows the lower frond surface: the naked sori are in depressions that give the upper leaf surface an embossed appearance. |
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Polypodium pellucidum. This view of the lower frond surface illustrates the naked, circular sori that are characteristic of this family. |
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Lepisorus thunbergiana. |