Monographs Details: Ceratolejeunea ceratantha (Nees & Mont.) Steph.
Authority: Dauphin L, G. 2003. . Fl. Neotrop. Monogr. 90: 1-86. (Published by NYBG Press)
Family:Lejeuneaceae
Synonyms:Ceratolejeunea poeppigiana Steph. ex Steph., Lejeunea ceratantha Nees & Mont.
Description:Species Description - Plants autoicous, dark-green to brown, leafy shoot 0.6-1.4 mm wide, sparsely branched. Stems in cross section 60-80 µm in diameter, medullary cells 9-18, ventral cells rectangular, 20-45 × 20-75 µm, dorsal rectangular, 25-40 × 25-55 µm. Branches sometimes attenuate towards the tips, appearing flagelliferous. Leaves imbricate, to shortly distant, leaf lobe ovate, 200-450 × 340-600 µm, margins entire, irregularly crenulate or with 1-7 teeth at the apex, teeth 1-2 cells long on a 1-2-celled base, 10-30 µm long, apex rounded to acute, plane; median leaf lobe cells isodiametrical, 10-30 × 15-40 µm, intermediate thickenings frequent, marginal leaf lobe cells quadrate to rectangular, 10-15 × 15-30 µm; oil bodies not seen; ocelli 25-35 × 20-60 µm, seriate, 1-3 per lobe, row 115-155 µm long; lobules ovoid and inflated or reduced, 0.2-0.4 the leaf lobe length, free margin plane. Utriculi absent, single or in pairs at the base of lateral branches. Underleaves ovate, slightly longer than broad, 110-280 × 140-300 µm, bifid to 1/2, lobes acute, uniseriate tip 1-2 cells long, margins entire, plane or rarely recurved. Androecia on main branches or intecalary on secondary branches, in spikes of 57 pairs of bracts, 830-950 µm long; bracteole obovate, 90 × 105 µm, bifid. Gynoecia on lateral branches with one sterile or repeatedly fertile innovation, bracts obovate, entire, dentate distally; bracteole ovate, 275-650 × 400-900, bifid to 1/2, dentate distally, teeth to 25 µm long, connate at the base with the bracts. Perianth emergent to 1/2, obconic, 340-500 × 570-750 µm, with four inflated horns, 70-110 µm long. Spores irregularly shaped, mostly rectangular, 17.5-25 × 45-75 µm, greenish brown, papillose-tuberculate, rosettes apparently absent.

Discussion:Ceratolejeunea ceratantha is recognized by the seriate ocelli in most of the leaves or single ocelli in some of them. Typically, the underleaves do not exceed twice the width of the stem and their lobes are acute. According to the original description (Montagne, 1840), the perianths of Ceratolejeunea ceratantha can rarely bear five horns, but I have not been able to confirm this observation.

The description of this species by Stephani (1913) is erroneous and refers to C. cornuta (Lindenb.) Steph. (e.g., "Amphigastria caulina magna, caule quadruplo latiora"), being apparently based on a specimen of the latter species mixed in with the isotype in G.

This species may be confused with the common Ceratolejeunea cubensis, from which it can be distinguished by the seriate ocelli in most of its leaves, the former usually having 1-2 basal or up to seven geminate ocelli. C. ceratantha can also be confused with C. rubiginosa Steph., which has moniliate ocelli. The presence of small teeth throughout the antical leaf margin in C. rubiginosa definitely separates it from C. ceratantha, which has the teeth restricted to the leaf apex.
Distribution:United States of America North America| Florida United States of America North America| Cuba South America| HolguĂ­n Cuba South America| Santiago de Cuba Cuba South America| French Guiana South America| Brazil South America| Rio de Janeiro Brazil South America|