Ceratolejeunea guianensis (Nees & Mont.) Steph.

  • Authority

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

  • Family

    Lejeuneaceae

  • Scientific Name

    Ceratolejeunea guianensis (Nees & Mont.) Steph.

  • Type

    Type. French Guiana. Without Province: "ad cortices arborum in sylvis humidis montis vulgo Serpent dicti" Leprieur 291 (lectotypus nov., PC; isolectotype G). (In the protologue, Leprieur 281 & 291 were cited (Montagne, 1840). Collection 281 was not found in PC, and the chosen lectotype has abundant material.)

  • Synonyms

    Lejeunea guianensis Nees & Mont., Colura guianensis (Nees & Mont.) Trevis.

  • Description

    Species Description - Plants monoicous or dioicous, dull green to light brown, leafy shoot 0.4-1.2 mm wide; sparsely branched. Stems 80-100 µm in diameter, medullary cells 14-19 in cross section, ventral cells in surface view rectangular, 15-45 × 15-60 µm, dorsal quadrate to rectangular, 40-55 × 40-50 µm. Microphyllous lateral branches frequent, leaflets with lobules ca. 0.5 the leaflet lobe length. Leaves imbricate, lobe ovate, 200-450 × 340-600 µm, apex rounded, rarely broadly acute, incurved, margins entire; median leaf lobe cells isodiametrical, 15-25 × 20-40 µm, intermediate thickenings frequent, marginal cells 12.5-20 × 12.5-20 µm; oil bodies not seen; ocelli 30-35 × 45-55 µm, basal, 1-2 per leaf, contiguous or isolate; lobules inflated or reduced, 0.3-0.4 the leaf lobe length, free margin plane or slightly involute, apical tooth slightly curved. Utriculi single or in pairs at the base of lateral branches. Underleaves orbicular to ovate, 160-250 × 160-240 µm, bifid to 1/2, lobes acute, ending in a uniseriate tip 1-2 cells long, sometimes connivent, margins entire, plane or rarely recurved. Androecia lateral on main branches or intercalary on secondary branches; spikes of 4-9 pairs of bracts, 730-1175 µm long; bracteole obovate, 105-140 × 125-175 µm, bifid to 1/4. Gynoecia on lateral branches with one sterile innovation, bracts ligulate to obovate, 500-520 × 780-860 µm, margins entire; bracteole orbicular to ovate, 375 × 590 µm, bifid to 1/4, lobes acuminate, margins entire, to crenulate distally or with a single distal tooth on both sides. Perianth not seen. Sporophyte not seen.

  • Discussion

    Ceratolejeunea guianensis is very closely related to Ceratolejeunea cubensis, from which it can be distinguished by its consistently entire leaf lobes with incurved leaves, the frequent microphyllous lateral branches bearing leaflets with very well developed lobules, and the smaller number of ocelli. The underleaves are usually scarcely broader than the stem, exceptionally up to twice the stem width. The perianth of the species has not been seen by the author. Fulford (1945) described the perianth in this species as having a four lows keels. The latter author and Schuster (1956) discuss the affinities of the species with C. laetefusca (Aust.) Schust., and even though both say they have seen the type, it is not clear from their specimen citations what material they saw. However, other vegetative characters, such as the more robust stems with incurved leaves and the presence of lateral microphyllous branches, serve to separate the two taxa. C. laetefusca is a more common species found throughout Neotropics, whereas few collections of C. guianensis are known. Fulford’s (1944b) report of vegetative regeneration for this taxon is based on specimens of C. laetefusca (Small et al. 6148, NY).

  • Distribution

    Known from southern United States and the Amazonian basin. A corticolous species, usually growing mixed with other Lejeuneaceae

    United States of America North America| Florida United States of America North America| Cuba South America| Oriente Cuba South America| Colombia South America| Guaviare Colombia South America| Venezuela South America| Carabobo Venezuela South America| Guyana South America| French Guiana South America|