Rough maidenhair fern Latin hispidus, hairy, + ulus, a diminutive suffix, alluding to the fine hairiness of the fern.
Plants stiff, erect, terrestrial. Rhizomes erect to decumbent. Fronds clustered at apex of rhizome, 6-40(-52) cm long, young fronds rosy pink. Stipes dark brown, rough, clothed with short dark fibrils and hairs. Blades 2-to 8-pinnate, deltate to ovate, dichotomously branched at 45o angle, each branch in turn repeatedly forking again; rachises hairy and fibrillose. Ultimate segments nearly sessile or with asymmetrically attached short stalks, often overlapping, dirnidiate, segments oblong-rectangular to diamond-shaped, firm, lower margin entire, upper margin dentate when sterile, both surfaces with fine, short, light hairs. Veins mostly ending in marginal teeth. Sori 6-14 per segment, U-shaped in marginal sinuses. Indusial flap with brown hairs.
Native to Asia (India to Africa), Australia, and Pacific islands, Adiantum hispidulum is now common in dry to wet forests, 90-1,250 (-1,825) m, on all the major islands and Kaho'olawe. It is widely cultivated and was first collected in the wild in Hawai 'i on O'ahu in 1928. It is now a common weed in many mesic, open-canopy forest locations, where it sometimes is an invasive groundcover.
Adiantum hispidulum may be easily recognized by fronds that repeatedly fork at 45° angles; stalks clothed with short, dark fibrils and hairs; and pinnules with short, light hairs.
Development of the Consortium of Pacific Herbaria and several of the specimen databases have been
supported by National Science Foundation Grants (BRC 1057303,
ADBC 1304924
and ADBC1115116).
Data Usage Policy. Continued support provided by the Symbiota Support Hub, a domain of iDigBio (NSF Award #2027654).
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