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 rufipilum Cardot , ( Fig. 2H , 20 ) Bulletin de l’Herbier Boissier , sér. 2, 8: 169 f. 4 (1908). TYPE . — Balade, Vieillard s.n. (“typus in herb. Boissier et herb. Cardot”). Vieillard 1735 p.p. ( lecto- , designated here PC [ PC 0096531]!; isolecto- , PC [ PC 0096534]!). DISTRIBUTION IN NEW CALEDONIA . — Hitherto only collected in two localities of North Province . TOTAL RANGE . — Endemic to New Caledonia . SELECTED SPECIMEN . — New Caledonia . Province Nord, Canala, Mt Bogota, altitude 500 m , X.1911 , Sarasin 391 , PC[PC0737584 (PC)]. DESCRIPTION Pseudautoicous Dwarf male plants on leaf axis of female branches. Plant Medium sized, red brown in herbarium, stems creeping. Branches Thick, medium sized, 5-13 mm long, when dry loosely spiralled, spiky, leaves erect to oblique, flexuous, carinate, the incurved apex unevenly directed, when moist erect to patent, straight. Branch leaves Large, 3-4.5 mm long, 0.5-0.8 mm wide, ligulate, widening slightly downwards, the apices usually obtuse to truncate, some of them shortly acute on the same branch, long aristate, the aristae thin, flexuous, red with hyaline tip, 0.4-1.5 mm long, basal parts of leaves 1/4-1/5 leaf length, costae thin, red, long excurrent, margins papillose crenulate. Upper cells Single-layered, of varying size ranging 10-20 µm long, 10-12 µm wide, thick walled, rounded, ovate to oblong, strongly bulging, the external walls strongly protruding, rounded to high conical with small papillae simple to furcate, the cells roughly aligned, marginal cells smaller in one row, transitional part usually short, transitional cells rectangular, thick walled, walls irregular, porous nodulous, with rounded to high single papillae, lower cells rectangular, elongate to linear, 35-85 µm long, 7-10(-15) µm wide, very thick walled, lumina straight, irregularly narrow 1/3-1/4 cell width, papillae null in basal parts to numerous near transitional parts. Perichaetia Indistinct, perichaetial leaf size and cell ornamentation like the vegetative ones,shape lanceolate,acuminate or acute,long aristate. Calyptrae Naked. Setae Long, 20-25 mm long, thin, flexuous, vaginulae hairless but with a few short paraphyses. FIG . 20. — Macromitrium rufipilum Cardot. : A , capsule; B , upper cells; C , basal cells; D , E , branch leaves; F , half transverse section in transitional part of branch leaf; G , transverse section in top quarter of branch leaf (fragment). All drawn from the lectotype except for E from the specimen Sarasin 391 . Scale bars: A, D, E, 1 mm; B, C, 10 µm; F, G, 20 µm. Capsules 2-2.5 mm long, narrowly oblong, sub-cylindric, smooth, rims plicate, brown, erect. Peristome Absent or reduced to a white ridge. REMARKS Macromitrium rufipilum is the most distinctive taxon in the Pulchrum group, essentially by the long reddish aristae and the conspicuous spiky and spiralled shape of the branches in dry condition. Other characters such as very long leaves, smooth basal cells, longer capsules allow to separate it from most of the specimens in the Pulchrum group, but they can also be observed in some M. pulchrum var. pulchrum specimens with short aristate and obtuse leaves. Compared to other species with long aristae, M. larrainii , M. humboldtense and M. panduraefolium , M. rufipilum differs from by many significant features (see under these species). The lectotype selected here is included in a pocket coming from the Cardot’s herbarium kept in PC. Ecological conditions are unknown.