Pellaea

Link, 1841

cliffbrakes

Pellaea is a of ferns in the Cheilanthoideae of the Pteridaceae, commonly known as cliffbrakes. The genus name derives from Greek 'pellos' meaning 'dark,' referring to the bluishgray stems characteristic of many . These ferns are primarily adapted to rocky , including cliff , rocky slopes, and bluffs. Molecular phylogenetic studies using chloroplast restriction site variation have clarified relationships within the genus, particularly resolving the P. glabella complex and establishing that P. atropurpurea is sister to this complex rather than the previously hypothesized P. breweri.

Pellaea by (c) Alan Rockefeller, some rights reserved (CC BY), uploaded by Alan Rockefeller. Used under a CC-BY license.

Pellaea by (c) redrovertracy, some rights reserved (CC BY), uploaded by redrovertracy. Used under a CC-BY license.

Pellaea by (c) Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger. Used under a CC-BY license.

Pronunciation

How to pronounce Pellaea: /pɛˈliːə/

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Identification

Members of Pellaea can be distinguished from other cheilanthoid ferns by their typically dark (bluishgray to purplish-) stems and rachises. within the show considerable morphological variation, with some exhibiting fertile and sterile fronds. P. atropurpurea is distinguished by its distinctly , purplish-brown rachis and dimorphic leaves with narrowly elongate fertile leaflets bearing sporangia along curled margins and broader, T-shaped sterile leaflets. P. glabella has a smooth (glabrous) rachis and is less commonly found growing in soil, typically restricted to exposed rock surfaces.

Images

Habitat

Primarily rocky including moist rocky canyons, slopes, bluffs, and cliff . While the is generally considered xericadapted, individual show habitat variation—P. glabella has been documented from atypical moist, shaded, north-facing limestone cliffs. P. atropurpurea and P. glabella frequently co-occur on north-facing dolomite bluffs in dry-mesic deciduous upland forest.

Distribution

North America, with documented occurrences in the United States (including the Ozarks, Oklahoma, Ohio) and Canada (Alberta and broader Canadian distribution). P. glabella occurs scattered throughout the Ozarks and a few northern counties. The represents a primarily North group within the cheilanthoid ferns.

Ecological Role

Cliffbrake ferns contribute to diversity on rocky substrates and cliff , often forming part of diverse fern on northfacing bluffs. They serve as plants for specialized including the fern-feeding Phytoliriomyza felti, whose leaf mines have been documented on P. atropurpurea.

Human Relevance

Collected by botanists and naturalists; subject of phylogenetic and taxonomic research. Some cultivated despite sporadic natural occurrence.

Similar Taxa

AspleniumBoth include found on rocky substrates and northfacing bluffs; Asplenium rhizophyllum ( fern) and A. platyneuron (ebony spleenwort) frequently co-occur with Pellaea species. Distinguished by spleenworts typically having green rather than dark stems and different leaflet arrangements.
CystopterisCystopteris bulbifera (bulblet fern) shares rocky cliff and can cooccur on dolomite bluffs; distinguished by winter foliage, bulblets on leaf undersides for , and greenish rather than dark stems.
WoodsiaAnother cliffdwelling fern in similar ; molecular studies indicate Woodsia is more distantly related within cheilanthoids, and lack the characteristic dark stems of Pellaea.