Icarus 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 : 209-211

Icarus Gasper & Salino , gen. nov. — Type: Icarus filiformis (A.Cunn.) Gasper & Salino. Figs. 4A , 6G .

Diagnosis: Rhizomes long-creeping, climbing trees; fronds di- or trimorphic; larger pinnae short-stalked; veins free, furcate.

Plants terrestrial, climbing by rhizomes; rhizomes long-creeping, climbing, non-stoloniferous, slender (2–4 mm diam.), densely clothed with bicolorous, dark brown, linear-lanceolate, squarrose scales; fronds di- or trimorphic, with different sterile fronds when climbing; stipes slender, relatively short, but longer in ones borne on climbing rhizomes, stramineous to tan, with a few scales similar to those of rhizomes proximally, with scattered scales to glabrescent distally; blades concolorous, lanceolate to narrow-oblong, with sterile terrestrial blades smaller than epiphytic ones, 2–6 pinna pairs somewhat reduced proximally, apices pinnatifid; rachises bearing scattered brownish scales and moderately dense, hyaline, flexuous, septate hairs 0.2–0.5 mm long; buds absent; aerophores absent; pinnae narrowly triangular, truncate at bases, sessile or short-petiolate, dentate-serrulate or minutely crenulate along margins; veins free, simple or furcate, each ending in a submarginal hydathode; sori linear, indusia brown, continuous, erose at margins, reflexed at maturity; x = 33.

Species number, comments, etymology, and distribution:— One species, endemic to New Zealand. This is a unique genus in the Blechnaceae , having trimorphic leaves. When in contact with soil, this species has small sterile leaves, and when climbing, much larger sterile leaves; the third leaf type, of fertile fronds, has greatly contracted pinnae ( Allan 1961). The dentate-serrulate or minutely crenulate pinna margins and the presence of adaxial hydathodes are other distinguishing characters. This is closely related to Austroblechnum , Blechnum , and Cranfillia (Gasper et al. in press). This name was coined by Raymond Cranfill in his unpublished notes, and we have decided to adopt it.

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.