Cheilolejeunea cuspidifera C.J. Bastos, A.M. Sierra & C.E. Zartman, 2016

Bastos, Cid José Passos, Sierra, Adriel M. & Zartman, Charles E., 2016, Three new species of Cheilolejeunea (Spruce) Steph. (Marchantiophyta, Lejeuneaceae) from northern Brazil, Phytotaxa 277 (1), pp. 36-46 : 39-40

Cheilolejeunea cuspidifera C.J. Bastos, A.M. Sierra & C.E. Zartman , sp. nov. ( Figs. 19‒34 , 46, 48, 50 )

The new species is characterized by its irregularly dentate leaf lobes, its acuminate apex, papillose cells, second lobule tooth elongated, underleaves with cuspidate lobes, and pycnolejeuneoid innovations.

Type:— BRAZIL: Roraima, Caracaraí, Serra da Mocidade , elev. 600 m, epiphyte, in forest, 31 Jan. 2016, Mário H. T. Araújo 1245 (holotype ALCB; isotype INPA) .

Plant robust, 0.8–1.0 mm wide, vegetative branch Lejeunea - type. Stem with 70 μm in diameter, in cross section with 7 cortical and 10 medullary cells, thick-walled. Ventral merophyte two cells wide. Leaves widely spreading to slightly suberect, imbricate; lobe ovate, convex, 410–460 μm long × 300–310 μm wide, margin entire to dentate with 1−3 prominent teeth on the dorsal margin near the apex, and 1−2 prominent teeth on the ventral margin, tooth 1−3 cells long and 1−4 cells wide at base, apex acute-acuminate, recurved, ending in a row of 1−2 cells, and 4−5 cells at base; basal cells large, oblong, 40 μm long × 20 μm wide, median cells 20‒28 μm long × 13‒15 μm wide, with a large, high rounded papilla projecting from the dorsal surface, trigones conspicuous, intermediate thickenings absent; oil bodies 2–3 per cell, coarsely segmented; ocelli absent; lobule ovate, inflated, 110–130 μm long × 90–110 μm wide, free margin involute, second tooth elongated, hyaline, oblong, hyaline papilla at distal base of second tooth, apical margin curved to semicircular, keel arched, strongly papillose, papillae 8–10 μm long × 13 μm wide at the base, rounded. Underleaves ovate, distant to contiguous, 280–440 μm long × 220–330 μm wide, bifid to 1/2, sinus U-shaped, lobes cuspidate, occasionally conivente, ending in 2–3 uniseriate cells, base rounded, insertion line curved. Androecia not found. Gynoecia terminal or on long lateral branches, pycnolejeuneoid innovations, bracts with obovate lobes, 540 μm long × 340 μm wide, toothed near acute-acuminate apex, lobules oblong-obovate, 430 μm long × 110 μm wide, bracteoles obovate, margins toothed near the apex, bifid, sinus widely acute to lunulate; perianth ellipsoid to obovate, 4-keeled, 850 μm long × 525 μm wide, rostrum short, 50 μm long × 40 μm wide, keels crenulate.

Additional material examined:― BRASIL. Roraima, Caracaraí, Serra da Mocidade , 600 m, growing on tree trunk, 30 Jan. 2016, Mário H. T. Araújo 1231 (paratype ALCB; isoparatype INPA) .

Etymology: The specific epithet refers to the distinct characteristic of the cuspidate form of the apices of the lobes of the underleaves.

Ecology and distribution: Cheilolejeunea cuspidifera thus far is only known from the type locality in Serra da Mocidade, Brazil, an isolated mountain in the Guyana highlands, in northern Amazonia. The species was collected growing as an epiphyte along a fast flowing creek together with Bazzania sp. , Ceratolejeunea cubensis ( Montagne 1842: 481) Schiffner (1893: 125) , C. spinosa (Gottsche in Gottsche et al. 1845: 402) Schiffner (1897: 595) and Syrrhopodon prolifer Schwägrichen (1827: 99) .

Figures

FIGURES 19‒34. Cheilolejeunea cuspidifera. 19. Gametophyte, ventral view. 20‒24. Leaf lobe apices. 25‒27. Underleaves. 28‒29. Lobules.30. Lobule apex showing second and first teeth.31. Marginal cells of the leaf lobules.32. Laminal cells. 33. Stem in cross section. 34. Gynoecial branch with innovation (from holotype, Mário H.T. Araújo 1245).

FIGURES 46‒51. Comparison between C. cuspidifera with C. lacerata. 46. Part of gametophyte of C. cuspidifera with perianth, ventral view. 47. Part of gametophyte of C. lacerata with gynoecia, ventral view. 48. Part of gametophyte with underleaves of C. cuspidifera. 49. Part of gametophyte of C. lacerata with underleaves. 50. Part of gametophyte of C. cuspidifera, ventral view. 51. Part of gametophyte of C. lacerata, ventral view (C. lacerata: from holotype - ALCB).