Woodwardia areolata (Linnaeus) T. Moore

Netted chain fern

Etymology Areolata means pitted.
Description Rhizome: long-creeping, blackish, scales brown, dense.
Frond: 70 cm high by 20 cm wide, deciduous, dimorphic, sterile fronds 10 cm shorter, emerging first, fertile midsummer,, blade/stipe ratio: 1:1.
Stipe: sterile: reddish brown below, straw-colored above; fertile: darker, to purple-black, sparsely set brown scales, vascular bundles: 2 elongate or peanut-shaped at stipe base, merging above to a tripartite structure.
Blade: 1-pinnate fertile, sterile less divided above where it is winged along the rachis, lanceolate, thin-textured, bright green later, reddish on emergence, scaly-glandular upon emergence but soon glabrous.
Pinnae: 7 to 12 pair, sterile alternate, lanceolate, fertile subopposite, contracted; margins minutely serrate to crenate; veins netted near the costa, free near the margin.
Sori: in chainlike rows, sunken into the lamina, but distinct, along the costae, indusium: flap-like, tucked under sporangia, disintegrating with age, opening towards the costa, sporangia: reddish-brown, maturity: late summer to early fall.
Culture Habitat: acidic bogs, seeps, and wet woods, rarely on rock of siliceous cliffs and ledges on northern edge of range. Distribution: coastal eastern North America and throughout southeastern North America. Hardy to -35°C, USDA Zone 3.
Distinctive Characteristics Superficial resemblance to Onoclea sensibilis, but distinguished by very different fertile fronds (linear sori vs. beads), sterile pinnae simple with serrate margins here while O. sensibilis has pinnatifid pinnae with entire margins on the lower frond.
Synonyms
Acrostichum areolatum Linnaeus
Lorinseria areolata (Linnaeus) C. Presl
Woodwardia angustifolia J.E. Smith, invalid
Woodwardia areolata
Woodwardia areolata. Habitat: sphagnum.  Photo © Shirley Denton, from her web site, with permission.
Notes
Dimorphism is sometimes incomplete, yielding a frond fertile at the top, sterile below.
Taxonomy Lorinseria areolata is still in play as a preferred name.
Woodwardia areolata
Woodwardia areolata. a) sterile and fertile fronds; b) chains of indusia; c) net venation.  Illustration by V. Fulford from Ferns and Fern Allies of Canada, William J. Cody and Donald M. Britton, 1989, © Agriculture Canada, used with permission.
Woodwardia areolata
Woodwardia areolata. Two peanut-shaped vascular bundles at the base (below) merging into a tripartite structure at the top of the stipe.  Drawing from Ferns of Northeastern United States, Farida A. Wiley, 1936.
Woodwardia areolata
Woodwardia areolata.  Illustration by Edgar Paulton, from How to Know the Ferns and Fern Allies, John T. Mickel, © 1979 Wm. C. Brown Co.
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