Macromitrium involutifolium subsp. ptychomitrioides (Besch.) Vitt & H. P. Ramsay

Thouvenot, Louis, 2019, A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia, Cryptogamie, Bryologie 20 (16), pp. 167-217 : 188-190

Macromitrium involutifolium subsp. ptychomitrioides (Besch.) Vitt & H. P. Ramsay

( Figs 1G , 10)

Journal Hattori Botanical Laboratory 59: 378 (1985).

M. ptychomitrioides Besch., Annales des Sciences naturelles,Botanique sér. 5, 18: 208 (1873). — Type: New Caledonia, Canala, Balansa 2540 (lecto-, BM [ Vitt & Ramsay 1985a]; isolecto-, PC[PC0096507]!).

M. plicatum Thér. , Bulletin de l’Académie internationale de Géographie botanique 17: 307 (1907). — Type: New Caledonia, “environs de Nouméa”, 1906, Franc s.n. (lecto-, designated here fide Guo in Sched. [2007] PC[PC0083710]!) syn. nov.

M. plicatum var. aristatum Thér. , Bulletin de l’Académie internationale de Géographie botanique 20: 99 (1910). — Type: New Caledonia, “environs de Nouméa”, Le Rat s.n. (lecto-, designated here: PC[PC0083716]!) syn. nov.

M. plicatum var. obtusifolium Thér., Diagnoses d’Espèces et de Variétés nouvelles de Mousses 8: 4 (1910). — Type: New Caledonia, “Monts Koghis, forêt, troncs d’arbre, alt. 300 m ”, Franc s.n. (lecto-, designated here fide Guo in Sched. [2007]: PC[PC0083719]!) syn. nov.

ILLUSTRATIONS AND DESCRIPTION. — Vitt & Ramsay (1985a).

DISTRIBUTION IN NEW CALEDONIA. — Species found in central (type specimen) and southern parts of the main island, from lowland up to 1100 m a.s.l. apparently avoiding seaside and highest mountains. It grows as an epiphyte in dry or wet forests preferably in edges, river or road sides, clearings, ect.

TOTAL RANGE. — New Caledonia, eastern Australia, Norfolk Island and Tubai Island in French Polynesia (Vitt & Ramsay 1985).

SELECTED SPECIMENS. — New Caledonia. Province Sud, Mont-Dore, Demazures forest, 330-420 m, 28.IX.2016, Thouvenot NC2364; Yaté, Rivière Bleue Natural Park, Pont Germain, 175 m, 5.X.2016, Thouvenot NC2372; Thio, Mt Ningua, 1100 m, 29.IX.2012, Larraín 35487; Farino, Grandes Fougères Natural Park, 370 m, 22.IX.2016, Thouvenot NC2339; Païta, Nodwé, 40-80 m, 24.X.2012, Thouvenot NC768.

DESCRIPTION

Here we provide the description of the type of M. plicatum and other specimens from New Caledonia.

Pseudautoicous

Dwarf male plants on leaf axis of female branches.

Plant

Medium to large young upper parts light green, main parts bronze-green to brown, creeping stems densely branched.

Branches

Medium to long (3-)5-25(-35) mm long, 1.5(-2) mm wide, straight to slightly curved, simple or fastigiate, when dry curly, with leaves erect to patent, individually twisted, strongly carinate, the apices circinate to enrolled, exposed by the margin, when moist erect to patent, sinuous with basal and middle parts recurved and apices incurved.

Branch leaves

Large 2.3-3.5(-4.2) mm long, 0.3-0.8 mm wide, narrowly lanceolate, apices acuminate, acute, sometimes narrowly obtuse apiculate, upper parts clear, transitional parts medium to long, basal parts differentiated, relatively short, (1/8-)1/4 the whole leaf length, costae strong prominent on back, ending in apices or short excurrent in mucrones, margins entire, recurved to one side near base.

Upper cells

Medium to large (8-)10-15 µm wide, single-layered, roughly aligned, rounded-quadrate, walls thickened at angles, bulging, smooth to low papillose, marginal cells smaller in one row or undifferentiated, transitional cells progressively becoming longer, short rectangular, unipapillose, papillae rounded scarce to numerous, concentrated near the base, lower cells elongated to linear (20-)25-45(-100) µm long, (6-)7-8 µm wide, walls porous, thick to very thick (2.5 µm), lumina narrow, straight, single rounded papillae null or scarce and localized.

Sporophytes

Numerous on each fertile branch.

Perichaetia

Inconspicuous.

Calyptrae

Plicate, hairy.

Setae

Short, 1.5-3.5 mm long, vaginulae with more or less conspicuous hairs.

Capsules

1-2 mm long, 0.5 mm wide, elliptic to narrowly oblong, smooth, rim slightly plicate, brown, erect.

Peristome

Absent.

REMARKS

This species is easily separated from other New Caledonian species by: 1) usually robust plants, profusely fertile, with fastigiated branches; 2) branch leaves erect-twisted with incurved to circinate apices giving the branches a curly habit; 3) leaves narrow, long lanceolate, sometimes ligulate, smooth in upper part; 4) lower cells elongate linear with straight lumina; 5) short setae; 6) perichaetia inconspicuous, not sheathing the seta base; 7) vaginulae and calyptrae hairy; and 8) capsules narrowly oblong to cylindrical, without peristome, with collapse rim. So, it differs from the other robust species in New Caledonia by many characters as straight lumina of basal cells, abundant sporophytes, smooth upper cells and inconspicuous perichaetia.The main difference in the varieties of M. plicatum described by Thériot is the apex shapes which are obtuse and mucronate in var. obtusifolius , aristate in var. aristatum whose type shows the highest values of leaf and branch sizes, respectively 4.2 mm long and 35 mm long. All these morphological features can be included in the variability of M. involutifolium subsp. ptychomitrioides as described by Bescherelle (1873) and Vitt & Ramsay (1985). In Vitt & Ramsay’s description and drawnings (1985) as well as in the specimens observed, the costa endings are variable, from below the apices to excurrent in short arista. In M. plicatum var. aristatum , the costa excurrence reaches 0.1 mm, in accordance with the character of

A B D C E H F G

“gigant” form of this specimen among the others (see above in the chapter “morphological characters”).

Figures

FIG. 1. — Dry branch habits of Macromitrium Brid. (I) A, M. microstomum Hook. & Grev.; B, M. cardotii Thér.; C, M. francii Thér.; D, M. laevigatumThér.; E, M. leratii Broth. & Paris.; F, M. taoense Thér.; G, M. plicatum Thér.; H, M. pilosum Thér.; I, M. pulchrum Besch. From type specimens (B, D, F-I), from specimens Thouvenot NC881 (A), NC2379 (E), from specimen Coulerie COU85 (C). Scale bars: 1 mm.