Lopholejeunea eulopha (Taylor) Steph.

  • Authority

    Gradstein, S. Robbert. 1994. Lejeuneaceae: Ptychantheae, Brachiolejeuneae. Fl. Neotrop. Monogr. 62: 216. (Published by NYBG Press)

  • Family

    Lejeuneaceae

  • Scientific Name

    Lopholejeunea eulopha (Taylor) Steph.

  • Type

    Type. "Pacific Islands," Nightingale s.n. (holotype, FH; isotype, NY).

  • Synonyms

    Lopholejeunea cocosensis L.Clark, Lejeunea eulopha Taylor, Phragmicoma eulopha (Taylor) Mitt.

  • Description

    Species Description - Autoicous. Plants ca. 2 cm long × 1.0-1.8 mm wide, glossy, blackish brown when dry. Branching sparse, Lejeunea-type, flagelliform branches lacking. Stems in cross section 6-7 cells across, composed of 13-15 epidermal cells surrounding a similar number of smaller medullary cells, epidermis subsymmetric, dorsal epidermal as large as or slightly larger than ventral epidermal cells, walls of epidermal cells thin or slightly thickened, inner walls more strongly thickened, all cell walls brownish pigmented. Leaves imbricate, dorsal lobe asymmetrically ovate-suborbicular, ca. 0.6-0.9 × 0.7-0.75 mm, somewhat falcate, apex rounded, usually recurved, margins entire, dorsal base rounded, ventral margin forming an angle of 100-150° with the keel; leaf cells in mid-leaf 20-45 µm, trigones large, radiate, intermediate thickenings frequent, conspicuous; oil bodies not observed. Lobules ovoid, not reduced, ca. 0.3 mm long, l/3× lobe length, strongly inflated-gibbous, abruptly flattened and folded at apex, free margin without distinct teeth. Under-leaves imbricate, reniform, ca. 0.3-0.45 mm long × 0.6-1.0 mm wide, 6-9× stem width, apex recurved or plane, bases rounded, insertion line curved. Androecia intercalary on long shoots, bracts in 3-4 series. Gynoecia on long branches, pseudo-innovations not observed, bract lobes asymmetrically ovate, acute, margins dentate-laciniate above, lobule lanceolate, distinctly extended beyond the keel, 1/2-2/3 × lobe length, margins toothed to laciniate; bracteoles suborbicular, ca. 1.2 mm long, apex rounded, usually recurved, rarely plane, margins dentate-laciniate above. Perianths immersed to emergent, obpyriform, in upper half with 4-5 sharp, unwinged, laciniate keels: 2 lateral keels, 2 ventral keels and usually a low dorsal keel; beak ca. 4 cells long, not recessed. Sporophyte not observed. Terpenoids: 5-hydroxycalamene is the major component of this species (Gradstein et al., 1985).

  • Discussion

    In Guyana and in the Amazon basin Lopholejeunea eulopha occurs on bark in virgin, dry evergreen forest on white sand. In Guyana it was found in walaba forest on the trunks and lower canopy branches of Eperua grandiflora trees. The Amazonian specimen came from tree trunks in Campina forest.

    Lopholejeunea eulopha is readily recognized by the recurved leaf apices, the broad, reniform underleaves and the large, rounded, dentate-laciniate female bracteole with undivided and usually recurved apex. Although known from only few neotropical collections, considerable variation is seen in the diagnostic features of this species. The degree of recurving of the apex of leaves and underleaves, for instance, varies and in some specimens they are barely recurved (e.g., type of L. cocosensis). The lobules of the female bracts are laciniate in the collections from Guyana but in other specimens they are subentire. The margins of the female bracteoles may be plane or strongly recurved.

    Lopholejeunea eulopha is most closely related to L. quelchii. Differences are discussed under the latter.

    Illustration: Mizutani, J. Hattori Bot. Lab. 45: 376, Fig. 1. 1979; VandenBerghen, Bull. Jard. Bot. Belg. 54: 428-432, Figs. 15-17. 1984; Thiers & Gradstein, Mem. New York Bot. Garden 53: 26, Fig. 8.1989.

  • Objects

    Specimen - 1049383, T. Nightingale s.n., Lejeunea eulopha Taylor, Lejeuneaceae (45.0), Marchantiophyta, isotype; Asia, Indonesia

  • Distribution

    Pantropical but rare in the neotropics (Northern South America, Cocos I.), at low elevations, up to 100 m. Lopholejeunea eulopha was first recorded from Cocos I. by Clark (1953), as L. cocosensis Clark, and subsequently from Guyana by Gradstein (1990).

    Costa Rica South America| Trinidad and Tobago South America| Guyana South America| Brazil South America| Amazonas Brazil South America|