Cheilolejeunea jackii (Prantl) Ye et al. (2015: 325)

Gil-Novoa, Jorge Enrique & Costa, Denise Pinheiro, 2023, Synopsis of the species of Cheilolejeunea (Marchantiophyta, Lejeuneaceae) in the Pacific dominion and Páramo province of tropical America, Phytotaxa 587 (2), pp. 73-120 : 97

16. Cheilolejeunea jackii (Prantl) Ye et al. (2015: 325) .—

Lejeunea jackii Prantl (1892: 17) .

Type:— ECUADOR. Manabí, Wallis s.n. (G, lectotype designated by Gradstein 2021).— Fig. 10Y –EE.

Plants light brown, 0.8–1.2 mm wide. Stems in cross section 90–100 µm in diameter, 14–15 epidermal cells, 13–19 × 10–12 µm; 32–34 medullary cells, 11–14 × 7–10 µm. Ventral merophytes 6 cells wide. Leaves distant, lanceolate with extended ventral base, flat to recurved in the ventral margin, 820–900 × 220–280 µm, margin entire, apex acute, dorsal margin curved; cells rectangular to long-hexagonal, smooth, conspicuous trigones; basal cells 14–30 × 7–8 µm, median cells 15–25 × 8–10 µm, marginal cells 18–28 × 9–12 µm. Lobules small, 1/7–1/4 of leaf length, triangular, free margin flat. Underleaves distant to contiguous, oblong to ovate, 580–600 × 300–310 µm, 3.5–4 × stem width, short bifid (1/10), margin entire, base strongly cuneate. Dioicous.Androecia not seen. Gynoecia on the main axis, lejeuneoid innovation; bracts obovate, 750 × 250 µm, apex acute, lobule 400 × 200 µm, bracteole ovate, 550 × 280 µm, bifid to 1/10. Perianth 5-keeled beak short. Vegetative reproduction unknown.

Distribution and habitat:—Neotropical, occurring in Nicaragua, Ecuador, and Bolivia ( Bastos & Gradstein 2020). This species was found growing in the study area on tree branches and shrubs, in lower montane rainforests, between 200–1200 m (Gradstein 2021), in the Galápagos Islands and western Ecuador provinces of the Pacific dominion. The record of C. jackii occurring in the Páramo ( Fig. 11 ), actually belongs to the Cauca province.

Notes:—This species can be easily recognized by its pendent growth habit, leaves distant, lanceolate with an extended ventral base, margins entire, apex acute, lobule reduced, and underleaves large, ovate, and short-bifid at the apex.

Specimens examined:— ECUADOR. Galápagos Islands: I. Pinta , 400–500 m, July 1976, Gradstein H508 ( COL, HUA, PMA); Pinzón, 400–460, 2 July 1976, Gradstein H481 ( COL, HUA) .

Figures

FIGURE 10. Cheilolejeunea holostipa A, B. Cladographs of fertile plants (solid ellipse = androecia, open ellipse = gynoecia with perianth); C. Shoot section in ventral view; D. Perianth with bracts and bracteole; E. Ventral merophyte with lobule; F. Leaf and lobule; G. Leaf lobe cells. Cheilolejeunea inflexa H-I. Cladograph of fertile plants (solid ellipse = androecia, open ellipse = gynoecia with perianth); J. Shoot section in ventral view; K. Portion of stem with perianth, L. Leaf and lobule, M. Apex of the lobule; N. Ventral merophyte with underleaf; O. Leaf lobe cells with trigones. Cheilolejeunea intertexta P. Cladograph of fertile plants (solid ellipse = androecia, open ellipse = gynoecia with perianth); Q-R. ventral view of apex of the stem, S. Perianth with bracts and bracteole, T. Ventral merophyte with underleaf; U. Leaf and lobule, V. Lobule, W. Underleaves, X. Leaf lobe cells. Cheilolejeunea jackii Y. Cladograph of fertile plants (solid ellipse = androecia, open ellipse = gynoecia with perianth), Z-AA. Shoots section in ventral view, BB. Ventral merophyte, CC. Leaves and lobules, DD. Underleaf, EE. Leaf lobe cells with trigones.

FIGURE 11. Distribution of Cheilolejeunea holostipa, C. inflexa, C. intertexta, and C. jackii in Pacific dominion and Páramo province.