Macromitrium larrainii Thouvenot & K.T.Yong

Thouvenot, Louis, 2019, A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia, Cryptogamie, Bryologie 20 (16), pp. 167-217 : 190-191

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

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.

Figures

FIG. 2. — Dry branch habits of Macromitrium (II) A, M. sarasinii Thér.; B, M.humboldtense Thouvenot & Franck Müll.; C, F, M. panduraefolium Thouvenot; D, M. larrainii Thouvenot & K.T.Yong; E, M. tongense Sull.; G, M. subvillosum Broth. & Paris; H, M. rufipilum Cardot; I, M. aurescens var. caledonicum (Thér.) Thouvenot. From type specimens (A-D, F, H, I), from specimens Müller NC755 (E), NC764 (G). Scale bars: 1 mm.

FIG. 12. — Macromitrium larrainii Thouvenot & K.T.Yong: A, upper part of dry branch; B-E, branch leaves; F, upper cells; G-H, branch leaf apices; I, capsule; J, calyptra; K, basal cells; L, transverse section in basal part of branch leaf; M, transverse section in top quarter of lamina; N, transitional cells. All drawn from the holotype, except I, J from the specimen Müller NC98. Scale bars: A, I, J, 1 mm; B-E, 500 µm; F, K, N, 10 µm; G, L, M, 50 µm; H, 100 µm.