Odontosoria quadripinnata Lehtonen, 2011

Lehtonen, S., 2011, A new species of Odontosoria (Lindsaeaceae) from New Guinea, Blumea 56 (3), pp. 216-217 : 216

Odontosoria quadripinnata Lehtonen , sp. nov. — Fig. 1

Frondes quadripinnatae. Pinnulae ultimae cum basi anguste cuneatae, surrhombeae cum incisuris non profundis.Sori uninervii, sporae monoletae. — Typus: Harrison-Gagné BHG 2141 (holo BISH), Papua New Guinea, Louisiade Archipelago , Misima Island, Mt Oiatau, epiphytic on log, 795 m, 26 March 1979 .

Etymology. The species has a distinctive quadripinnate laminar dissection, hence the name.

Herb. Rhizome probably short creeping, solenostelic, stout, c. 1 cm diam. Rhizome scales medium to pale brown, triangular, to 5 mm long, c. 20 seriate at the base. Petioles dull brown, c. 6 mm diam at the base, c. 60 cm long, all axes abaxially rounded, adaxially grooved. Lamina oblong to triangular, at least to 60 cm long, 50 cm wide, chartaceous to subcoriaceous, quadripinnatepinnatifid, dark green above, much lighter green below. Major pinnae at least 6 to a side, alternate, the lower ones with a stalk up to 3 cm long, the upper ones gradually subsessile, elongatetriangular, to 35 by 20 cm, equal sided. Larger secondary pinnae triangular, shortly petiolulate, acuminate, up to 15 cm long, 7 cm wide, pinnate to bipinnate, 5–12 free pinnae or pinnules to a side, upper pinnules cuneate, confluent. Ultimate pinnules cuneate, subrhombic with shallow incisions, c. 7–10 by 2– 4 mm, about twice as long as wide, sterile pinnules more rounded than fertile ones. Veins elevated, usually 2–3 times forked, 0.5–1 mm apart. Sori occupying just a single vein. Indusium entire, pouch-shaped,

1 Department of Biology, FI-20014 University of Turku, Finland; e-mail: [e-mail].

c. 0.7 mm wide, 1 mm long, reaching the margin. Sporangia c. 200 by 150 µm, annulus with 15– 20 indurated cells. Spores monolete, bean-shaped, pale, smooth, c. 50 by 30 µm.

Distribution & Ecology — New Guinea, wet tropical montane forests at elevations between c. 800 –2000 m. Terrestrial or epiphytic on fallen trunks.

Additional specimen. NEW GUINEA, Morobe Province , Kuper Range,along unpaved track to Biaru,wet montane forest; on muddy banks of gently flowing stream, 2021 m, 7°31'S 146°48'E, 29 Sept. 1988, Takeuchi 4081 (BISH).

Note — Kramer (1971) mentioned that several collections of a quadripinnate form of O. retusa exists from New Guinea and Manus, but that their taxonomical status is uncertain. He believed that at least some of them represented hybrids, possibly between O. retusa and O. chinensis (L.) J.Sm. (1857: 430). Hybrid origin was assumed because of abortive spores. However, the specimens examined here have fully developed spores and are unlikely hybrids. Monolete spores are rare among the Odontosoria species. Besides O. quadripinnata , monolete spores are present in O. chinensis , O. biflora (Kaulf.) C.Chr. (1906: 464) , and O. veitchii (Baker) Parris (1992: 151) . These species also share a short, typically uninerval, sori. Odontosoria chinensis and O. biflora were resolved as sister species pair in the cladistic analysis, but the phylogenetic relationships of O. quadripinnata and O. veitchii remain uncertain, due to the lack of molecular data ( Lehtonen et al. 2010). However, it is probable that all Odontosoria species with monolete spores are closely related.

Figures

Fig. 1 Odontosoria quadripinnata Lehtonen. a. Fertile segments adaxially;b. fertile segments abaxially; c. terminal segment abaxially; d. rhizome scale; e. part of the rhizome; f. holotype. All drawings (a –e) are based on the holotype (f). — Drawn by S. Lehtonen.