Diplazium expansum Willd.
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Authority
Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.
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Family
Athyriaceae
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Scientific Name
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Description
Species Description - Rhizome stout, erect, 15-20 mm thick (excluding stipe bases), clothed at apex with thick, dark brown, lanceolate scales up to 12 mm long and 2.5 mm wide near base, acuminate-attenuate at apex, the margins entire, the cell structure dense and fibrous. Fronds arching, 1.2-3 m long; stipes much shorter than the blades, brown, clothed near base with scales like those of rhizome, otherwise glabrescent to minutely appressed-pubemlous. Blades narrowly ovate to ovate, longacuminate at apex, up to 80 cm broad or more, 2-pinnate-pinnatifid; rhachis straw-colored, glabrate, at most bearing a few scattered pluricellular hairs, otherwise naked. Pinnae 10-15 pairs, subopposite or altemate, stalked, lanceolate or lance-oblong, long-acuminate, 7-17 cm broad; free pinnules up to 12 pairs on larger pinnae, sessile or short-stalked, narrowly deltate-oblong to oblong, 1.2-2.3 cm broad, truncate and nearly equilateral at base, obtuse to long-acuminate at apex, margins crenate to deeply lobed or pinnatifid; costae and other parts rather densely puberulous with reddish-septate hairs abaxially, the costules also with a few pale brown, narrowly linear, appressed scales; ultimate veins simple or forked, slightly prominulous. Sori nearly basal to inframedial on veins, 2-4(-6) mm long; indusium light brown, the basal part dense, the marginal part delicately subclathrate near the slightly erose edge.
Distribution and Ecology - General Distribution. Greater Antilles, St. Vincent, Mexico, Guatemala, and from northern South America to Brazil and Peru. Consists of several local races, some of which have been known by different names, and whose relationships are not understood. Distribution in Puerto Rico. Confined to the Cordillera Central, where it has been found in rather few localities; recorded from Adjuntas, Jayuya, Orocovis, and San German. Habitat. Sheltered rocky ravines, glades, and stream-banks at high elevations (850-1050 m), rare.
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Discussion
Type. Bredemeyer, from Caracas, Venezuela (Herb. Willd. 19948, B).
Syn. Asplenium radicans Schkuhr, Krypt. Gew. 1: 70, 1809, in part, not Linnaeus, 1759; not Biplazium radicans Desvaux, 1827.
Asplenium expansum (Willdenow) K. Presl, Reliq. haenk. 1:46. 1825.
Athyrium expansum (Willdenow) Milde, Bot. Zeitung (Berlin) 1870:353. 1870, not Moore, I860.
Asplenium hartianum Jenman, J, Bot, 24: 268, 1886, (Type. Sherring, 1874-79, from Jamaica, isotype US.)