Balantiopsis montana (Colenso) J.J.Engel & G.L.Merr.

Thouvenot, Louis & Müller, Frank, 2021, Contribution to the bryophyte flora of New Caledonia IV. Species new to the country, new localities together with taxonomic notes, Cryptogamie, Bryologie 20 (13), pp. 181-196 : 183

* Balantiopsis montana (Colenso) J.J.Engel & G.L.Merr.

SPECIMENS EXAMINED. — New Caledonia. North Province, Pouébo, Diahoué, Tooliwök, 20°29’8”S, 164°41’19”E, on rocks aside a waterfall, mixed with Flatbergium novo-caledoniae , 710 m, 10.XI.2019, Laudereau NC2780 (PC0712105); South Province, La Foa, Koghis, along the path to Mt Moné, on an earthy slope in a clearing, 545 m, 15.IX.2012, Thouvenot NC1477 (PC0779857); Mount Mou near Païta, along the path from the sanatorium over Poudio to the summit, montane rainforest, on forest floor, 1150 m, 10.IX.2001, Müller NC371; Sarraméa, along the path from Sarraméa to Plateau de Dogny, 21°37’S, 165°52’E, earthy slopes, c. 500 m, 05.IX.2003, Müller NC816; Nouméa 12 km NNE, along the path from Auberge de Koghi to Cascade de Koghi, humid rainforest, on rocky slopes, 550 m, 08.IX.2001, Müller NC26.

COMMENTS

Two Balantiopsis species were hitherto known in New Caledonia: Balantiopsis neocaledonica Pearson and B. diplophylla (Hook.f. & Taylor) Mitt. Engel (1968) treated B. diplophylla in a broad sense, but in a more recent publication ( Engel & Smith Merrill 1997) the authors give a description of B. diplophylla in a narrower sense. The species is characterized by cells typically scattered in the distal third of the ventral lobe, not in evident transverse rows, the median cells are polygonal to rather short-rectangular (c. 2.5:1), the ventral lobes are rather broadly elliptic to broadly ovate. Following these authors, the range of B. diplophylla outside New Zealand must be reassessed and we suspect that most of what has been so far given as B. diplophylla from New Caledonian collections actually belong to B. montana . The specimens of B. diplophylla reported from New Caledonia must be checked in order to ensure the presence of this species in the country.

Our material of Balantiopsis collected in New Caledonia does not match the characters of B. diplophylla . Here we add B. montana to the New Caledonian flora. It is separated from B. diplophylla by 1) the shape of the leaf lobes, more elongated, 2× longer than wide; 2) the arrangement of leaf cells which are transversally aligned in the upper half of the leaf lobes; and 3) the median cells elongaterectangular (to 4:1) ( Fig. 1M, N ). Based on the diagnose by Pearson (1922), B. neocaledonica can be distinguished by the underleaves bifid vs deeply bifid to trifid, the leaf lobes with mostly entire margins and apices less ciliate, but this species is only known from the type (not seen) and its taxonomic status needs more investigation. B. montana was hitherto stated to be endemic to New Zealand ( Engel & Smith Merrill 1997), but it also occurs in North and South Provinces of New Caledonia.

Figures

FIG. 1. — A-H: Telaranea parvifolia (Steph.) J.J.Engel & G.L.Merr. A, shoot, dorsal view; B, C, stem transverse sections; D, main stem leaf; E, main stem underleaf; F, branch leaf; G, H, branch underleaves.From Thouvenot NC2617. I-L: Lejeunea leratii (Steph.) Mizut. I, shoot, ventral view; J, lobule ventral view; K, underleaf; L, leaf cell. From Thouvenot NC2741. M, N, Balantiopsis montana (Colenso) J.J.Engel & G.L.Merr. M, leaf, dorsal view (lobule cells omitted); N, underleaf. From Laudereau NC2780. Scale bars: A, M, N, 200 µm; B-H, J, L, 100 µm; I, 500 µm; K, 20 µm.