Icarus filiformis (A.Cunn.) Gasper & Salino, 2016

Gasper, André Luís De, Dittrich, Viníciusantonio De Oliveira, Smith, Alan R. & Salino, Alexandre, 2016, A classification for Blechnaceae (Polypodiales: Polypodiopsida): New genera, resurrected names, and combinations, Phytotaxa 275 (3), pp. 191-227 : 211

1. Icarus filiformis (A.Cunn.) Gasper & Salino , comb. nov. — Lomaria filiformis A. Cunn., Companion Bot. Mag. 2: 363. 1837. — Blechnum filiforme (A.Cunn.) Ettingsh., Denkschr. Kaiserl. Akad. Wiss., Math. -Naturwiss. Kl. 24: 21, t. 6 f. 5. 1864.

Lomaria Willd., Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 3: 160. 1809. — Lectotype (designated by J. Smith, Hist. Fil. 303. 1875): Lomaria nuda (Labill.) Willd., Sp. Pl. ed. 4, 5(1): 289. 1810. Figs. 4B , 6H .

Stegania R.Br., Prod. Nov. Holl. 152. 1810. — Lomaria sect. Stegania (R.Br.) J.Sm., Hist. Fil. 304. 1875. — Type: Stegania nuda (Labill.) R.Br. , based on Onoclea nuda Labill. [= Blechnum nudum (Labill.) Luerss. ]

Plants terrestrial; rhizomes erect, stout, sometimes forming small trunks, stoloniferous or not, clothed with bicolorous or concolorous, dark brown or blackish, linear-lanceolate to acicular, entire scales, these brown with a blackened mid-stripe; fronds dimorphic; stipes stout, long, brown to blackish, with scales like those of rhizomes, but smaller, scaly, pilose, or glabrous; blades lanceolate or oblong-elliptic, pinnate or pinnatisect, gradually reduced proximally, proximal pinnae auriculate, apices pinnatisect, discolorous (adaxial side dark green, abaxial side brownish in dried state); rachises with a few scales on abaxial surfaces, or glabrous; buds absent; aerophores absent; pinnae adnate to subpetiolulate, oblong, linear to lanceolate, plane to slightly revolute at the entire or minutely crenulate margins; veins free, 1- to 2-furcate, tips ending at pinna margins, sometimes ending in hydathodes adaxially, or slightly enlarged; sori linear, indusia continuous, lacerate or erose at maturity; x = 28.

Species number, comments, and distribution:— This widely dispersed genus comprises six species, and occurs in South America, South Africa, Australia, and New Caledonia. Lomaria has historically been a name applied to species with dimorphic leaves, differing from Blechnum s.s., which has monomorphic leaves. The genus is characterized by having deeply grooved rachises and discolorous blades; two species with green spores have been reported ( Lloyd & Klekowski, 1970, Sundue & Rothfels 2014). Lomaria is closely related to Lomaridium plus a clade formed by Austroblechnum , Blechnum , Icarus , and Cranfillia (Gasper et al. in press).

Figures

FIGURE 4. General appearance of the genera of Blechnaceae subfamily Blechnoideae (G-S). A. Icarus filiformis (WELT P009478); B. Lomaria nuda (P01557820); C. Lomaridium fragile (MEXU 149093); D. Lomariocycas aurata (QCA7004842); E. Neoblechnum brasiliense (FURB06585); F. Oceaniopteris cartilaginea (P01630912). G. Parablechnum cordatum (FURB06639); H. Sadleria pallida (MEXU 956078); I. Struthiopteris spicant (P01658104). Vouchers are indicated by herbarium barcodes.

FIGURE 6. Habitat of Blechnaceae genera. A. Blechnum occidentale; B. Brainea insignis; C. Cleistoblechnum eburneum. D. Cranfillia vulcanica; E. Diploblechnum fraserii; F. Doodia caudata; G. Icarus filiformis; H. Lomaria spannagelii; I. Lomaridium acutum. Photos from: A. Luis Adriano Funez; B. Ralf Knapp; C. Ralf Knap; D. Julie F. Barcelona; E. Michael Sundue; F. Paulo Araújo; G. WELT herbarium; H. Vinícius A.O. Dittrich; I. Tiago João Cadorin. Reproduced with permission from the authors.