Lejeunea mamilliflora Pocs 2021, sp. nov.
Creators: name: Pócs, Tamás
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Porellales
Lejeuneaceae
Lejeunea
Lejeunea mamilliflora

description: Lejeunea mamilliflora Pócs, sp. nov.   (Figs 5; 7D)  
 DIAGNOSIS. —The species is characterised by the extremely large, blister like mamillae on the two ventral perianth carinae. Mamillae on the perianths occur in some other Lejeunea species too, but never so large, blister like ones arranged in increasing size. The other character is the very frequent, alternating development of male and female gamaetoecia on the main stem.   
 TYPE. — Madagascar, Fianarantsroa Prov., Haute Matsiatra reg., Parc national de l’Andringitra. Montane rainforests on the W side of Korokoro river, around camp II, 750-1000 m, 22°13’S, 47°01- 02’ E. T. Pócs, G. Kis & A. Szabó, 20-23.IX.1994, 9472/ BG (holoon microslide, EGR).   
ETYMOLOGY. — Named after the large mamillae increasing in size downwards on the ventral perianth carinae.  
 OTHER SPECIMEN OBSERVED. — Same locality as the type, T. Pócs et al., 9472/AK (para-, TAN). At the type locality it is very rare, hopefully will turn up from other localities too.   DESCRIPTION  
 Dry specimens in herbarium greenish yellow, shoots 1.2- 1.5 mm wide, up to 12 mm long, sligthly branching. Stem up to 80 µm wide, with hyalodermis and two ventral merophytes. The leaves are slightly imbricate to contiguous, horizontally spreading at an angle of 90° to the stem, 700-900 × 560-650 µm, more or less parallel sides or slightly falcately ovate with rounded apex. Lobe cells isodiametric hexagonal, 25-30 µm in diameter, with thin wall, medium sized, well developed trigones and intermediate thickenings. Marginal cells somewhat smaller, 20-25 µm, forming a slightly crenulate border. Oil bodies not seen. Lobules small, inflated, triangular or ovate, 160 × 120 µm. The only lobule tooth circular with an ental hyaline papilla at its proximal base. It is separated only by one cell from the keel. Underleaf lobes at base 3-5 cells wide and 6-7 cells long, acute lanceolate, stretching to about 6× stem width, with a very wide, U shaped sinus. Rhizoids colorless, forming irregular bundles at unerleaf bases. Autoicous or sometimes paroicous. Male and female gametangia densely and randomly alternating on very short side branches along the main stem. Androecium globose, about of 200 µm diameter, hang at an angle of 40-60° in postical direction and consist of 2-3 pairs of concave male bracts. Only one small bracteole below the first pair of bracts. Gynoecia turn at 60° towards antical direction. Female bracts about half perianth length, ovate with rounded apex. Bracteole equal length of bracts, its apex only to 1-2 cells depth bilobed. Perianth cordate, 400-500 × 325-360 µm, compressed with two side wings and two ventral keels, which are decorated by 2-3 rows of densely arranged, blisterlike, globose mamillae growing in size downwards from 20 to 30 µm diameter. On the side wings these mamillae develop only weakly, in one row. Beak 2-3 cells high, up to 50 µm length. Sporophyte and vegetative reproduction not known.
description: Published as part of Pócs, Tamás, 2021, Notes on the bryophytes of Madagascar 3. Six new Lejeuneaceae species, pp. 129-141 in Cryptogamie, Bryologie 20 (8) on page 136, DOI: 10.5252/cryptogamie-bryologie2021v42a8, http://zenodo.org/record/12215212