Macromitrium involutifolium (Hook. et Grev.) Schwägr. subsp. involutifolium

Thouvenot, Louis, 2019, A review of the genus Macromitrium Brid. (Orthotrichaceae, Bryophyta) in New Caledonia, Cryptogamie, Bryologie 20 (16), pp. 167-217 : 186-187

Macromitrium involutifolium (Hook. et Grev.) Schwägr. subsp. involutifolium

Species Muscorum Frondosorum, Suppl. 2,2: 144 (1827).

M. noumeanum Besch. Annales des Sciences naturelles, Botanique sér. 5, 18: 208 (1873). — Type: New Caledonia, “ad truncos in sylvis prope Noumea”, Balansa 2535; “Canala, supra cataractam”, Balansa 2539; “In Nova-Caledonia comm. Schimper”, Krieger s.n. (lecto-, Balansa 2535 BM-Besch; syn-, BM-Besch [ Vitt & Ramsay, 1985a]; isolecto-, PC108006 [BESB1948]!); isosyn-, PC[PC0083697]!).

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

DISTRIBUTION IN NEW CALEDONIA. — We are only aware of a few specimens of this plant from New Caledonia and cannot define the New Caledonian distribution or ecology of this species which is frequent in eastern Australia from sea level to mid elevation, on rocks or trunks Vitt & Ramsay 2006).

TOTAL RANGE. — New Caledonia and eastern Australia ( Vitt & Ramsay 2006).

SELECTED SPECIMEN. — New Caledonia. Province Nord, Pouhembout, Forêt Plate, 300 m, 7.IX.2003, F. Müller NC758 (DR).

DESCRIPTION

Macromitrium involutifolium subsp. involutifolium is characterized by: 1) medium sized plants, much fertile, with branches medium, up to 10 mm long; 2) branch leaves erect-twisted with incurved to circinate apices giving the branches a curly habit; 3) leaves narrow, long lanceolate, sometimes ligulate, 0.5 mm wide, 2.1-2.7 mm long, smooth in upper part; 4) lower cells few, rectangular with straight lumina; 5) short setae, 1.5-5 mm long; 6) perichaetia inconspicuous, not sheathing the seta base; 7) vaginulae and calyptrae hairy; and 8) capsules long elliptical, with single peristome and plicate rim erect and firm.

The latter character distinguishes the type subspecies from M. involutifolium subsp. ptychomitrioides which has cylindrical capsules with collapse rims and lacking peristome as well as a usually more robust habit and leaves with more defined basal parts made of longer cells.

B C D A E F G H J K I

Depauperate specimens could be confused with Macromitrium francii , but the latter has smaller leaves, strongly carinate, different in shape, and densely papillose especially in upper parts. In addition, its setae are very short and the hairs of the vaginulae reach the capsules which are shorter, ovoid to elliptic.