Ceratolejeunea laetefusca (Austin) R.M.Schust.

  • Authority

    Dauphin L, G. 2003. . Fl. Neotrop. Monogr. 90: 1-86. (Published by NYBG Press)

  • Family

    Lejeuneaceae

  • Scientific Name

    Ceratolejeunea laetefusca (Austin) R.M.Schust.

  • Type

    Type. United States. Florida, Donnell Smith s.n. (lectotype (Schuster, 1956), NY).

  • Synonyms

    Ceratolejeunea caducifolia (Spruce) Steph., Ceratolejeunea patulistipa Steph., Ceratolejeunea integrifolia A.Evans, Ceratolejeunea deficiens Herzog, Lejeunea laete-fusca Austin

  • Description

    Species Description - Plants dioicous or rarely autoicous, light brown, leafy shoots 0.3-1.2 mm wide, sparsely branched. Stems fragile, 35-115 µm in diameter; medullary cells 3-15 in cross section, ventral cells quadrate to rectangular, 10-25(-40) × 20-45(-60) µm, dorsal cells mostly rectangular, 15-40 × 15-0(-55) µm. Branches fragile, often appearing bare because of caducous leaf fall. Leaves slightly imbricate, lobe ovate, 190-260(-390) × 240-360(-500) µm, apex rounded, curved when dry, plane when moist, margins entire or irregularly crenulate, rarely toothed at the apical region, teeth 0-3, to 25 µm long; median leaf lobe cells mostly hexagonal or elliptical, 10-20(-25) × 10-25(-40) µm, walls thin, regularly thickened, intermediate thickenings rare to frequent, weak, marginal cells quadrate to rectangular, 7.5 × 10-30 µm; oil bodies not seen; ocelli elliptical, 15-25 × 25-50 (-60) µm, basal, contiguous or isolate, 2(1-3) per leaf; lobules inflated or reduced, 0.2-0.4 the leaf lobe length, free margin involute or plane, with a single apical tooth, hyaline papilla proximal. Utriculi absent. Underleaves orbicular to ovate, 80-180(-360) × 75-180(-370) µm, bifid to 1/2, lobes acuminate, ending in a uniseriate tip 1-2 cells long, margins entire and plane. Vegetative reproduction by caducous leaf lobes frequent to rare. Androecia lateral on main branches, or intercalary on lateral or main branches, in spikes of 2-8 pairs of bracts, spikes 350-1225 |iim long; bracteole ovate to orbicular, 95-170 × 100-170 µm, bifid to 1/3, lobes acute. Gynoecia on lateral branches with one or two sterile or repeatedly fertile innovation; bracts obovate, 270-460 × 415-680, margins entire or toothed distally, teeth to 25 µm long, bract lobule ligulate, 165 × 425 µm; bracteole ovate, 220-380 × 385-610 µm, bifid to 1/2, lobes acuminate. Perianths more or less globose, 260 × 370 µm, with four low, rounded keels, sometimes with a fifth smaller antical keel. Sporophyte not seen.

  • Discussion

    Specimens of Ceratolejeunea laetefusca from drier environments often appear with bare stems because of caducous leaves, which had led Fulford (1945) to keep them as a separate species, C. caducifolia (Spruce) Steph. These caducous-leaved plants are small in size, may have only three or four medullary cells in transversal stem section, and the leaf lobule is frequently reduced. In some specimens some branches appear to be caducous and might serve as asexual propagules. The number of medullary stems cells varies, and overlaps with those of plants which have few or no caducous leaves. More robust specimens of C. laetefusca have about 10 medullary cells in stem cross section, and can either have or lack caducous leaves.

    Fulford (1945) treated Ceratolejeunea integrifolia as a synonym of C. guianensis, but based on the type of the latter (see under C. guianensis), I cannot agree with that placement.

    This species is closely related to Ceratolejeunea cubensis (Mont.) Schiffn., from which it differs in the lack of utriculi and perianth horns. Plants of C. cubensis are frequently autoicous, the leaf lobe margin can be entire or weakly to strongly toothed at the apex, and in robust specimens the ocelli tend to be also geminate. In contrast, C. laetefusca is usually sterile with only female bracts, with entire leaf lobe margins, and two basal, contiguous or isolated ocelli.

    Some have tried to separate these two species by general plant and cell size (cf. Schuster, 1980), but the plant size and number of medullary cells in Ceratolejeunea laetefusca vary so strongly that robust specimens overlap in size with C. cubensis.

    Most authors have considered Ceratolejeunea laetefusca strictly dioecious, but monoicous plants have been collected too (e.g., Langlois 201, US; Gradstein 9937, Dauphin 2780 (GOET)).

    Illustrations: Fulford (1945, p. 383); Schuster (1980, p. 923).

    Distribution and Ecology: Widely distributed in the Neotropics, from southeastern United States to southern Brazil, not excluded from the Brazilian planalto. This species grows in dry or moist primary and secondary lowland forests up to open submontane habitats, from 500 to 1300 m, in open places on living bark, rotting bark and rocks, frequently mixed with other bryophytes.

  • Distribution

    United States of America North America| Florida United States of America North America| Mexico North America| Oaxaca Mexico North America| Belize Central America| Corozal Belize Central America| Honduras Central America| Atlántida Honduras Central America| Costa Rica South America| Guanacaste Costa Rica Central America| Bahamas South America| Cuba South America| Guantánamo Cuba South America| Las Villas Cuba West Indies| Guadeloupe South America| Trinidad and Tobago South America| Suriname South America| Nickerie Suriname South America| Ecuador South America| Los Ríos Ecuador South America| Peru South America| San Martín Peru South America| Brazil South America| Acre Brazil South America| Amazonas Brazil South America| Minas Gerais Brazil South America| Pernambuco Brazil South America| São Paulo Brazil South America| Bolivia South America| Beni Bolivia South America| Cochabamba Bolivia South America|