identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
E502D47A633FFFB320B1FB56FA31F879.text	E502D47A633FFFB320B1FB56FA31F879.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Lejeunea tridenticulata A. V. Tourinho. P & D. F. Peralta A 2025	<div><p>Lejeunea tridenticulata A.V. Tourinho P. &amp; D.F. Peralta, sp. nov.</p><p>Figure 1.</p><p>Type:— BRAZIL. Mato Grosso: <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-55.085556&amp;materialsCitation.latitude=-15.407222" title="Search Plazi for locations around (long -55.085556/lat -15.407222)">Chapada dos Guimarães, Chapada dos Guimarães National Park, Vale do Véu da Noiva trail, gallery forest vegetation</a>, 15°24’26” S, 55°05’08” W, 513 meters in elevation, on branches, associated with Meteorium nigrescens (Hedw.) Dozy &amp; Molk. (1848: 160) 15-07-2018, Peralta, DF. 23999; Canestraro, BK; Stech, M. (Holótipo SP [ac. 494663]) .</p><p>Diagnosis:— Lejeunea tridenticulata is characterized by the presence of dimorphic underleaves, bifid to trifid, markedly dentate along the margin, with 2 to 4 teeth. It is morphologically similar to Lejeunea laetevirens Nees &amp; Montagne (1842: 469) and Lejeunea boryana Mont. (1838: 47) due to the presence of marginal teeth on the underleaf, but differs from both in the number of teeth along the margin and in having a trifid underleaf, as well as small triangular trigones, a straight dorsal margin, isodiametric cells, and the absence of oil bodies and a hyaline papilla in the lobule.</p><p>Description. Plants shiny, light green to pale green in herbarium, small gametophyte, 2.5 mm wide, prostrate, with vegetative branching of the Lejeunea - type. Stems with a ventral merophyte 2 cells wide. Leaf lobe horizontally inserted on the stems; lobes orbicular to oval, 0.3 mm wide to 0.5 mm long, slightly imbricated, apex rounded, dorsal and ventral margins straight and entire, median cells isodiametric, 16–30 µm long × 10–20 µm wide, larger at the base, thin-walled, trigones absent or small-triangular. Cuticle smooth and oil bodies, not seen. Leaf lobule inflated, ovaltriangular, 0.2 mm long × 0.1 mm wide, composed by 25–35 cells, apical tooth with one cell present, hyaline papilla not seen, keel weakly arched, slightly crenate due to convex cells. Underleaves large, dimorphic in its shape and in its margins, distanced, 0.3–0.5 mm long × 0.2–0.4 mm wide, 3–4 times greater than the thickness of the stems, cordate base, insertion line arched, bifid to trifid, divided to 1/x of its length, apex acute ending with one cell, sinus when bifid varying from U to a wide opening, when trifid varying from acute (V) to U. insertion of the underleaf sligthly curved. Androecia, gynoecia, and perianth not seen.</p><p>Distribution and ecology</p><p>Lejeunea tridenticulata . is, so far, known only from a single specimen collected in the Central-West region of Brazil, in the state of Mato Grosso, in plateau areas within gallery forest vegetation of the Cerrado phytogeographic domain, at an elevation of 513 meters. It was found associated with eight other bryophyte species, with Meteorium nigrescens (Hedw.) Dozy &amp; Molk. as the most common species, growing as an epiphyte on the branches of a living tree.</p><p>Etymology</p><p>The specific epithet refers to the trifid underleaves with denticulate margins, the main characters that distinguish the species.</p><p>Discussion</p><p>The most comprehensive and recent treatment of Lejeunea for Brazil is that of Bastos &amp; Gradstein (2020), which provides a key to Brazilian species along with descriptions including geographic distribution, habitat, distinguishing characters, and illustrations, as well as information on synonymies, recently described species, lectotypifications, and proposals for new combinations.</p><p>The literature cited in this article and other important works on the genus Lejeunea Lib., such as Reiner-Drehwald (2000), Reiner-Drehwald &amp; Goda (2000), Gradstein &amp; Costa (2003), and Bastos &amp; Yano (2009) describe the structure of the underleaves as varying from entire to bifid, with the entire margin sometimes presenting a small lateral projection or tooth derived from one cell on each side of the margin. This specific characteristic is observed in Lejeunea laetevirens Nees &amp; Mont and Lejeunea boryana Mont (Flora e Funga do Brasil 2025).</p><p>The new species proposed here shows similarity to Lejeunea laetevirens Nees &amp; Mont due to the presence of teeth on the margin of the underleaves and a lateral protuberance derived from the projection of one cell. However, its underleaves are bifid and narrow, bearing only one tooth on each side of the margin. The main characteristic that distinguishes this species from Lejeunea tridenticulata, (Figure 1) is the underleaf dimorphism, appearing as bifid or trifid; additionally, when bifid, the underleaves bear 2–4 teeth on the margin. Other characters also differentiate them: Lejeunea laetevirens exhibits inconspicuous trigones, a slightly arched dorsal margin, hexagonal cells, oil bodies in its cells, and a hyaline papilla at the proximal base of the apical tooth of the lobe. In contrast, the new proposed species, Lejeunea tridenticulata, may present small triangular trigones, a straight dorsal margin, isodiametric cells, and lacks oil bodies and hyaline papillae on the lobe.</p><p>It is worth highlighting another species that exhibits similar characteristics, Lejeunea boryana, also characterized by having bifid leaf lobes with teeth along their margins. However, it differs from L. tridenticulata by being a smaller plant, ranging from 500 to 750 µm in width, bearing underleaves that are only bifid with a sinus ranging from deeply acute to lunate, and with margins bearing only a single tooth (Flora e Funga do Brasil 2025).</p><p>Thus, based on the results obtained, it is worth emphasizing the importance of floristic surveys as a means to enhance the understanding of existing biodiversity. These studies are fundamental not only for recording already known species but also for enabling the discovery of new species, contributing to a more complete mapping of the country's flora.</p><p>The new species can be distinguished from Lejeunea laetevirens and Lejeunea boryana based on the characteristics selected in the following key:</p><p>1. Underleaves as long as wide, bifid, with lobes not ending in 1–2 cells, and often with one tooth on the margin........ L. laetevirens .</p><p>2. Underleaves smaller, bifid to 2/3 of their length, with acute lobes ending in 1–2 cells, and the lateral margin bearing one tooth ..... ........................................................................................................................................................................................... L. boryana .</p><p>3. Underleaves often wider than long, bifid to trifid, triangular apex, frequently ending in a single cell, with 1–4 teeth on the margin ....................................................................................................................................................................... Lejeunea tridenticulata .</p></div>	https://treatment.plazi.org/id/E502D47A633FFFB320B1FB56FA31F879	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Pinheiro, Ana Vera T.;Peralta, Denilson F.	Pinheiro, Ana Vera T., Peralta, Denilson F. (2025): A new species of Lejeunea Lib. (Lejeuneaceae) from Brazilian Savanna. Phytotaxa 721 (2): 196-200, DOI: 10.11646/phytotaxa.721.2.8, URL: https://doi.org/10.11646/phytotaxa.721.2.8
