Cheilolejeunea caracariensis 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 : 38

Cheilolejeunea caracariensis C.J. Bastos, A.M. Sierra & C.E. Zartman , sp. nov. ( Figs. 11‒18 , 42, 44 )

The new species is characterized by its conically shaped lobule with plane free margin, composed of large, rectangular to subrectangular cells, narrow and semicircular apical margin, papillose laminal cells, enlarged papillae predominantly along the lobule keel, triangular-ovate leaf lobe, with an acute apex.

Type:— BRAZIL: Roraima, Caracaraí, Serra da Mocidade , elev. 600 m, epiphyte at base of tree, 29 Jan. 2016, Mário H. T. Araújo 1217a (holotype ALCB; isotype INPA) .

Plant small, 490–540 μm wide, branching Lejeunea - type. Stem 50 μm in diameter, transverse section with 7 cortical and 7‒10 medullary cells. Ventral merophyte two cells wide. Leaves widely spreading from stem to suberect (60–80°), contiguous to weakly imbricate; lobe triangular-ovate, convex, 190‒280 μm long × 140–190 μm wide, dorsal margin arched, crenulate, ventral margin weakly arched to straight, apex acute, mostly curved; cells oblong, 18–26 μm long × 13–15 μm wide, thin-walled, trigones large, intermediate thickenings absent; oil bodies not seen; ocelli absent; lobule conic, suberect from stem (45°), 150–180 μm long × 110–140 μm wide, inflated along the keel, free margin plane, composed of large, rectangular to subrectangular cells, 18–25 μm long × 10–13 μm wide, involute at the apex lobule, apical margin narrowed, semicircular, second tooth acute, short, first tooth indistinct, hyaline papilla at the distal side of the second tooth, keel arched, strongly papillose, papillae large, 10 μm long × 15 μm wide. Underleaves small, 150–170 μm long × 120–170 μm wide, ovate to suborbicular, distant, bifid to 1/3 its length, sinus acute, lobes obtuse, base cuneate, insertion line straight. Androecia and gynoecia not found. Vegetative propagules not observed.

Etymology: In reference to the type locality.

Ecology and distribution: Cheilolejeunea caracariensis thus far is only known from the type locality from Serra da Mocidade in Brazil, an isolated “tepui” in the Southern portion of the Guyana Plataeu of northern Amazonia. The species was growing as an epiphyte at the base of a tree at the edge of a fast flowing creek together with other Lejeuneaceae such Ceratolejeunea cornuta ( Lindenberg 1829: 23) Stephani (1913: 419) , Harpalejeunea tridens ( Bescherelle & Spruce 1889: 181) Stephani (1913: 263) , Cheilolejeunea lineata (Lehmann & Lindenberg in Lehmann 1832: 53) Stephani (1890: 82), Prionolejeunea aemula (Gottsche in Gottsche et al. 1845: 338) Evans (1904: 219) and Lepidolejeunea involuta (Gottsche in Gottsche et al. 1845: 350) Grolle (1984: 504).

Figures

FIGURES 11‒18. Cheilolejeunea caracariensis. 11. Gametophyte, ventral view. 12. Leaf lobe apex. 13. Underleaf and lobule. 14: Free margin of leaf lobule. 15. Leaf lobule apex. 16. Laminal cells. 17‒18. Stems in cross sections (from holotype, Mário H.T. Araújo 1217a).

FIGURES 42‒45. Comparison between C. caracariensis with C. oncophylla. 42. Part of gametophyte of C. caracariensis, ventral view. 43. Part of gametophyte of C. oncophylla, ventral view. 44: lobule keel of C. caracariensis. 45. Lobule keel of C. oncophylla (C. oncophylla: from Schäfer-Verwimp 12742 - EGR).