Macromitrium ligulaefolium Broth.

Thouvenot, Louis, 2019, A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia, Cryptogamie, Bryologie 20 (16), pp. 167-217 : 194-196

Macromitrium ligulaefolium Broth.

( Fig. 14 )

Öfversigt af Finska Vetenskaps-Societetens Förhandlingar 40: 170

(1898).

M. brevipilosum Thér. , Bulletin de l’Académie internationale de Géographie botanique 18: 253 (1908). — Type: New Caledonia, “versant ouest du Mont Koghis, 300 m ”, Franc s.n. (lecto-, designated here PC[PC0137607]!; isolecto-, PC[PC0137608-10, PC0096495]!).

M. cucullatum Thér. , Bulletin de l’Académie internationale de Géographie botanique 19: 307 (1907). — Type: New Caledonia, “environs de Nouméa, 1906”, Franc s.n. (lecto-, designated here fide Guo in Sched. [2007] PC[PC0083639]!).

Macromitrium perminutum Broth. & Paris, Öfversigt af Finska Vetenskaps-Societetens Förhandlingar 51A (17): 15 (1909). — Type: New Caledonia, “L’Hermitage prope Nouméa, ad cortices arborum”, Le Rat s.n. (holo-, H fide Vitt in Sched. [1983] H.BR[H. BR2563014]!; iso-, PC[PC0083637]!).

ILLUSTRATIONS AND DESCRIPTION. — Vitt (1983). Here we provide a description of the type of M. brevipilosum .

DISTRIBUTION IN NEW CALEDONIA. — M. ligulaefolium is very frequent anywhere below 700 m, rarely up to 1150 m.

TOTAL RANGE. — Australasia. Eastern Australia, Tasmania, New Zealand ( Vitt & Ramsay 2006). Common in Australia and New Zealand, it was considered as endemic of these countries but, as stressed by Vitt (1983), this species was expected to “have a more extensive range in the Pacific Islands”.

SELECTED SPECIMEN. — New Caledonia. Province Nord, Touho, Tipiléi valley, 100-400 m, 12.X.2012, Thouvenot NC1015 (PC); Pombéi, 249 m, 12.X.2016, Thouvenot NC2275; Hienghène, La Guen (Panié massif), 550 m, 8.X.2012, Thouvenot NC1024 (PC); Poindimié, Povila, 350 m, 11.X.2012, Thouvenot NC916; Poindimié, Nessapoué, 40 m, 4.IX.2012, Thouvenot NC907; Province Sud, Païta, Nodwé, 40-80 m, 24.X.2012, Thouvenot NC1004; Thio, Mt Ningua, 1120 m, 29.IX.2012, Thouvenot NC864; Dumbéa, Montagne des Sources Strict Nature Reserve, 950 m, 21.IX.2016, Thouvenot NC2061; Yaté, Rivière Bleue Nature Park, 175 m, 5.X.2016, Thouvenot NC2225; Plaine des Lacs, on Retrophyllum minor , 245 m, 6.X.2016, Thouvenot NC2369 (PC); Mont Dore, Prony village, 10 m, 21.IX.2012, Thouvenot NC875 (PC); Farino, Grandes Fougères Nature Park, creek Houé, 425 m, on Araucaria sp. , 22.IX.2016, Thouvenot NC2338; Nouméa, Jean-Marie Tjibaou Cultural Centre, 1 m, mangrove, 24.IX.2012, Thouvenot NC899 (PC); Koghis, c. 700 m, 9.IX.2001, F. Müller NC198 (DR).

DESCRIPTION

Pseudautoicous

Dwarf male plants on leaf axis of female branches.

Plant

Small, creeping stems densely branched.

Branches

Short, thin, 3-4(-5) mm long, 0.6-1 mm wide, when dry curly, not funiculate, with leaves erect, individually twisted, carinate, the apex incurved to circinate, exposed by the margins, when moist erect to patent, the apices usually little incurved.

Branch leaves

Medium, 1.2-1.8 mm long, 0.28-0.35 mm wide, ligulate obtuse with apiculate apices, upper parts obscure to translucent, transitional parts long, basal parts short, costae strong,

protruding on the back, ending in the apiculi, margins papillose crenulate.

Upper cells

Single-layered, small, quadrate-hexagonal with rounded lumina, c. 10 mm wide, thin walled, bulging, with 3-5 small papillae per cell, the cells roughly aligned, transitional cells quadrate to short rectangular, thick walled, bulging, with single rounded papillae, lower cells few, rectangular elongate, 15-40 µm long, 10 µm wide, thick walled, lumina relatively wide, straight, cells with single rounded papillae scarce but present on most of the leaves.

Perichaetia

Inconspicuous, perichaetial leaves lanceolate, progressively acuminate, shorter and wider than the vegetative ones.

Calyptrae

Naked at base, with a few short hairs on the top.

Setae

Short, 2-5(-6) mm long, erect, vaginulae with inconspicuous hairs.

Capsules

Short exserted, 1-1.2 mm long, elliptic, smooth, rim plicate, red brown, small, incurved.

Peristome

Absent.

Spores

Not seen.

REMARKS

In New Caledonia, Macromitrium ligulaefolium is characterized by: 1) very short branches tightly curly when dry; 2) short setae; 3) ligulate branch leaves medium length; 4) a few basal cells long rectangular; 5) calyptrae with short hairs confined to the top; 6) vaginula hairs inconspicuous; and 7) peristome absent. As stressed by Thériot (1908), the plants here brought together under this name may be separated from the other New Caledonian Macromitrium with short branches, short setae and plicate capsule rims by the short and scarce hairs of the calyptrae.

In the superficially similar Macromitrium brachypodium , M.francii and M. pilosum the vaginulae are conspicuously long hairy, the branches longer and the setae shorter.

M. hemitrichodes var. sarasinii has numerous long basal cells with narrow lumina.

Vitt & Ramsay (1985a: 448) considered M. brevipilosum as a synonym of M. ligulaefolium , without examination of the type. We could find type specimens in PC so that we agree with these authors, on the basis of most straits, but these New Caledonian plants have smaller leaves, less narrowly ligulate in most cases. Furthermore, the peristome is absent while, in M. ligulaefolium , it may be present, reduced or absent. Two more names synonymized by Vitt & Ramsay (op. cit.), M. cucullatum and M.perminutum are plants singularized by nearly smooth cells and upper half of branch leaves strongly carinate, difficult to flatten between slide and slip cover, so that the apex seems cucullate. Their branch length, 2-3 mm long, are the smallest in the range.

Macromitrium ligulaefolium was frequently collected from seaside to medium elevation, rarely above 700 m, often in half-light, relatively dry condition such as mangroves, anthropized environments, secondary forests, forest edges, shrublands, dry forests, wet forest with higher Araucarias, ect. Always epiphytes, on usually various kind of trunks, even on the usually moss free Melaleuca quinquenervia , on branches and twigs, rarely on thatched roof, ect.

Figures

FIG. 14. — Macromitrium ligulaefolium Broth.: A-E, branch leaves; F, branch leaf with dwarf male plant; G, basal cells; H, upper cells; I, dwarf male plant. Drawn from M. brevipilosum Thér. lectotype (F-I) and isotype PC0096495 (A-D) and M. cucullatum Thér. lectotype (E). Scale bars: A-F, 500 µm G, H, 10 µm; I, 100 µm.