Gleichenella pectinata (Willd.) Ching

Dicranopteris pectinata (Wilid.) Underw. Bull. Torrey
Club 34: 260. 1907.
Meriensia pectinata Willd. Sv. Vet.-Akad. Handl. II. 25 : 168. 1804. Mertensia brasiliana Desv. Ges. Nat. Freunde Berlin Mag. 5: 329. 1811. Meriensia canescens Kaulf. :Enum. Fil. 38. 1824. Mertensia emarginaia Raddi, PI. Bras. 1 : 72. 1825. Gleichenia niiida Presl, Rel. Haenk. 1 : 70. 1825. Gleichenia brasiliana Spreng. Syst. Nat. 4 : 27. 1827. Mertensia elata Desv. M^m. Soc. Linn. Paris 6 : 201. 1827.
Gleichenia Hermanni Hook. & Grev. Ic. Fil. 1: pi. 14 (excl. syn.). 1827. Not G. Hermafini R. Br. 1810.
Mertensia nitida Presl, Tent. Pterid. 51. 1836.
Gleichenia Hookeri J. Smith, I^ond. Jour. Bot. 2 : 381. 1843.
A laxly ascending diffuse plant, forming extensive thickets ; rhizome wide-creeping, 3-5 mm. in diameter, light brownish-castaneous, conspicuously scabrous from the persistent bases of numerous deciduous castaneous articulate hairs ; primary leaf-axis at first erect, stout, 3-6 mm. in diameter, stramineous to light-brown, terete, elongate, eventually declining ; primary lateral branches several pairs, opposite, stipulate, repeatedly and unequally pseudodichotomous, a falsely S3rmpodial naked flexuous secondary axis formed by the alternate production of the unequal secondary branches, the shorter ones bearing a pair of pinnae or again unequally forked and bearing two pairs of pinnae ; lower nodes of the lateral branches inconspicuously stipulate ; included terminal bud of each dichotomy invariably abortive; pinnae variable, 10-25 cm. long, 1.5-6 cm. broad, sessile, fully pectinate (the outer basal segments often somewhat prolonged), subfalcate, unequally lanceolate or oblong-lanceolate to linear, attenuate, glaucous below (sometimes conspicuously so), glabrous to glabrate or (especially in narrow forms) having the costae and veins sparsely clothed with deciduous stellate or substellate slender ferruginous scales ; segments variable in size, oblong to linear-oblong, connected by a narrow wing ; veins 3-5-forked, slightly elevated below ; sori numerous (or frequently altogether lacking), multisporangiate, nearly medial, invariablj'borne upon the distal veinlet of each group.
Type locality : Near Caracas, Venezuela.
Distribution : Of wide distribution in tropical America ; general in the West Indies ; on the continent extending from Mexico to Rcuador and Brazil. Polymorphic.