Macromitrium rufipilum Cardot

Thouvenot, Louis, 2019, A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia, Cryptogamie, Bryologie 20 (16), pp. 167-217 : 206-207

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.

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.

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. 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.