Leptoscyphus incisus Gradst., F. R.
Creators: name: Oliveira-Da-Silva, Fúvio Rubens
name: Gradstein, S. Robbert
name: Viana, Pedro Lage
name: G., Carlos Ernesto
name: Schaefer, R.
name: Ilkiu-Borges, Anna Luiza
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Jungermanniales
Lophocoleaceae
Leptoscyphus
Leptoscyphus incisus

description: Leptoscyphus incisus Gradst., F.R. Oliveira-da-Silva & Ilk.-Borg., sp. nov.   (Fig. 5)  
Autoicous. Plants prostrate with ascending branches, branching usually by innovations, sometimes with stoloniferous ventral branches with rhizoids and rudimentary leaves. Leaves succubous to almost transversally inserted, subopposite, subrectangular, bifid to trifid to ⅓-¼ of leaf length; leaf cells with nodulose and confluent trigones. Underleaves absent or rudimentary. Perianths long-ovoid to subcylindrical, mouth circular to broadly elliptic, entire, marginal cells little diferentiated, isodiametrical to subquadrate, outer cell walls thickened.  
 HOLOTYPE. — Brazil. Roraima state, Uei tepui, Bonnetia woodland, on tree trunk, 5°01’30”N, 60°36’45”W, alt. 2103 m, 8.IV.2019, Viana et al. 6264 (holo-, MG).   
 ETYMOLOGY. — The epithet refers to the incised leaves, an unusual character in neotropical Leptoscyphus.   
 DISTRIBUTION AND HABIT. — Leptoscyphus incisus Gradst., F.R. Oliveira-da-Silva & Ilk.-Borg., sp. nov. is only known from cloudy forest with dominance of Bonnetia sp. on Uei tepui, state of Roraima, northernmost Brazil, growing on the trunks of treelets at about 2100 m.   DESCRIPTION   Sexual system   
Autoicous.   Habit   
Plants prostrate with ascending branches, orange to red-brown, 1.3-2.6 mm wide on leafy ascending branches, considerably smaller in prostrate branches (to 0.5 mm wide), branched usually by innovations, innovations intercalary, originating ventro-laterally at the perianth base in the ventral axil of a bract, sometimes with intercalary, stoloniferous ventral branches with rhizoids and rudimentary leaves.   Stem   
 In cross section with epidermis weakly differentiated, one layer of c. 26 thick-walled epidermal cells surrounding c. 45 somewhat thin-walled medullary cells, the medullary cells little larger than epidermal cells.    Leaves   
Succubous to almost transversally inserted, widely to obliquely spreading, contiguous to imbricate, subopposite, subrectangular, 1.5-2× longer than wide, (0.5-) 0.7-1.3 mm long, 0.35- 0.5 mm wide, apex bifid to trifid, incised ⅓-¼ of leaf length, uniseriate tips 2-4 cells long, margins entire, dorsal margin ± straight, ventral margin arched; leaf cells (sub)isodiametric in prostrate branches, 20-40 µm, elongate in ascending branches, 25-60 µm long, 15-25 mm wide, trigones nodulose, sometimes confluent, intermediate thickenings rare in elongate cells only, cuticle smooth.   Underleaves   
Absent or rudimentary.   Rhizoids   
Colorless, little ramified at the tip forming an adhesive patch.   Androecia   
On innovations from axil of bracts or intercalary on the stem, with 4-5 pairs of bracts; bracts imbricate, subopposite, 0.5- 0.7 mm long, 0.3-0.5 mm wide, apex bifid to trifid, incised ⅓ of bract length, uniseriate tips 2-4 cells long, margins entire; bracteoles rudimentary (inconspicuous).   Gynoecia   
Terminal on ascending branches and on innovations, usually repeatedly innovated, with one pair of bracts; bract subopposite, 0.7-1.3 mm long, 0.35-0.5 mm wide, apex bifid; bracteoles absent or rudimentary.   Perianths   
Long-ovoid to subcylindrical, (1.0-) 1.6-2.2 mm long, 0.5- 1.1 mm wide, terete, narrowed to the mouth, the apex in profile truncate, mouth circular to broadly elliptic, entire, marginal cells little differentiated, isodiametrical to subquadrate, outer cell walls thickened.  REMARKS  
 The new species shares several features with Leptoscyphus autoicus (J.J. Engel & Gradst.) Vanderp. & Gradst. (basionym Physotheca autoica J.J.Engel & Gradst.) from Ecuador, such as the autoicous sexuality, branching via innovations and perianths terete, inflated, bladder-like, with a narrow, fully entire mouth (Engel & Gradstein 2003). The two species also have rather similar habitats, occurring as epiphytes in low woody vegetation on very mineralpoor soil. Leptoscyphus incisus sp. nov. clearly differs from L. autoicus, however, in the bifid to trifid leaves and reduced underleaves. In L. autoicus the leaves are undivided, suborbicular to oblate, and underleaves not reduced. Very small underleaves are otherwise also seen in Leptoscyphus subg. Anomylia (R.M.Schust.) R.M.Schust., and 2-3-fid leaves occur in the African L. infuscatus (Mitt.) E.W.Jones (L. sect. Physoscyphus Grolle). The latter species, however, has dioicous sexuality, much larger underleaves and a flattened perianth with a wide, toothed mouth, similar as in most Leptoscyphus species.
description: Published as part of Oliveira-Da-Silva, Fúvio Rubens, Gradstein, S. Robbert, Viana, Pedro Lage, G., Carlos Ernesto, Schaefer, R. & Ilkiu-Borges, Anna Luiza, 2022, Bryophytes from Uei tepui (Serra do Sol), with liverworts new to Brazil and the description of Leptoscyphus incisus sp. nov., pp. 51-64 in Cryptogamie, Bryologie 20 (4) on pages 60-62, DOI: 10.5252/cryptogamie-bryologie2022v43a4, http://zenodo.org/record/12215143