Aspidium gaudichaudii Mett.; A. apiifolium sensu Hillebr., non Schkuhr; A. apiifolium Schkuhr var. pubescens Hillebr.; A. sinuatum sensu Gaudich., non Labill.; Nephrodium apiifolium sensu Hook. & Am., non Schkuhr; Sagenia apiifolia sensu Brack., non (Schkuhr) J. Sm.; S. hippocrepis sensu Brack., non C. Presl [Tectaria cicutaria (L.) Copel. subsp. gaudichaudii (Melt.) W. H. Wagner in unpublished checklists]

Common names:       'iwa 'iwa lau nui (large-leaved 'iwa'iwa)

Endemic                

Name honors Charles Gaudichaud-Beaupre (1789-1854), French pharmaceutical botanist on Capt. Louis Claude Desaulses de Freycinet's Uranie voyage to Hawai'i in 1819, and again in 1841 on La Bonite under Capt. August-Nicolas Vaillant.

Plants medium-sized to large, terrestrial. Rhizomes decumbent. Fronds 30-140 cm long, clustered. Stipes glossy, mahogany brown or purple, scaly only at bases, scales scattered, lanceolate, brown. Blades 1-pinnate-pinnatifid to bipinnatifid, deltate, dark green; rachises becoming winged distally, tips finally becoming deeply pinnatifid with sinuate, Ianceolate lobes separated by broad angular sinuses, membranous. Pinnae 3-10 pairs below pinnatifid blade tips, nearly opposite, lanceolate, pinnae at bases short-stalked, becoming adnate distally, deeply pinnatifid, adaxial costae and major veins densely covered with stubby, multicellular, usually obtuse-tipped hairs. Ultimate segments deeply crenulate to lobed. Veins prominent, anastomosing freely to form areoles with occasional included veinlets, areoles adjacent to pinna costae long, linear. Sari arranged in lines near veins leading to cren-ulate lobes, mostly on included veinlets. Indusia kidney-shaped.

Found in moist, shady valleys and gulches, 210-1,250 m, all major islands.

Tectaria gaudichaudii may be recognized by its often large, triangular, dark green blades; distally winged rachises; pinnae with large, deeply scalloped lobes; and characteristic semicircular arrangement of the round stipe vascular bundles. Its many veins join to form areoles with included veinlets. It may be distinguished from Tectaria incisa by its greater dissection, blade tips that are pinnatifid (versus similar to lateral pinnae), and more numerous and more deeply lobed pinnae.