A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia Author Thouvenot, Louis Saint Léon, 66000 Perpignan (France) thouvenot. louis @ orange. fr louis@orange.fr text Cryptogamie, Bryologie 2019 2019-10-16 20 16 167 217 http://dx.doi.org/10.5252/cryptogamie-bryologie2019v40a16 journal article 10.5252/cryptogamie-bryologie2019v40a16 1776-0992 12215595 Macromitrium larrainii Thouvenot & K.T.Yong , ( Figs 2D , 12 ) Cryptogamie, Bryologie 36: 344-346, fig. 1-15 (2015). TYPE . — New Caledonia . North Province , Hienghène, summit of Mt Panié, c. 1640 m , 9.X.2012 , Larraín 35846 ( holo- , PC [ PC 0167650]!; iso- , NOU ! KLU , F , CONC , NY , S ). ILLUSTRATIONS AND DESCRIPTION . — Thouvenot & Yong (2015) ; Müller et al. (2016) . DISTRIBUTION IN NEW CALEDONIA . — So far only known from Mt Panié, the highest summit in the country. TOTAL RANGE . — Endemic to North Province of New Caledonia . SELECTED SPECIMENS . — New Caledonia , Province Nord, Mt Panié, along the hiking trail from RPN3 to the summit, c . 1200 m , 13.IX.2001 , F. Müller NC98 & NC202 (DR). DESCRIPTION Macromitrium larrainii is well characterised by:1) long branches up to 25 mm long; 2) lanceolate branch leaves distinctively slender, laminae widest near base, very narrow and asymmetrical above; 3) a very shaggy habit due to the long, thin aristae up to 1 mm long and excurrent costae of the branch leaves irregularly arranged; 4) cells smooth throughout the leaves; 5) upper leaf cells irregular in shape and size and basal ones linear and evenly thick-walled, with straight lumina; and 6) setae 8-10 mm long. A B C F E D G H I FIG . 11. — Macromitrium laevigatum Thér. : A , top of branch with perichaetium and sporophyte; B -D , F , branch leaves; E , upper cells; G , basal cells; H , branch leaf apex; I , transverse section in upper third of branch leaf. All drawn from the lectotype. Scale bars: A, 1 mm; B-D, F, 500 µm; E, G, H, 10 µm; I, 20 µm. Epiphyte growing on barks in rain and cloud forests and scrublands, at higher altitudes, this species is candidate to micro-endemic status since it is only known from two collecting places relatively close one from the other, in the northernmost part of the Central Range.