Marsupella subemarginata Bakalin & Fedosov, 2019

Bakalin, Vadim A., Fedosov, Vladimir E., Fedorova, Alina V. & Nguyen, Van Sinh, 2019, Integrative taxonomic revision of Marsupella (Gymnomitriaceae, Hepaticae) reveals neglected diversity in Pacific Asia, Cryptogamie, Bryologie 20 (7), pp. 59-85 : 63-64

Marsupella subemarginata Bakalin & Fedosov , sp. nov.

( Figs 2 ; 5 A-C)

Plants greenish brownish to rusty, without purple pigmentation. Stem cross section with outer layer cells larger, with thickened cell walls. Leaves transversely inserted, shortly decurrent dorsally, leaf margin plane or revolute, concave-canaliculate, midleaf cells relatively small. Dioicous.

TYPE. — Russia. Kamchatka Territory, Ganalsky Range, Bakening Volcano area, upper course of Pravaya Kamchatka River, 53°56’45”N, 158°01’56”E, 900 m alt., moist boulder near temporary stream in alpine belt, field no. K-44-16-15, 04.VIII.2015, leg. Bakalin V. A. (holo-, VBGI; iso-, MW).

PARATYPES. — Russia. Kamchatka Territory, Ganalsky Range, Bakening Volcano area, upper course of Pravaya Kamchatka River, 53°56’45”N, 158°01’56”E, 900 m alt., moist boulder near temporary stream in alpine belt, field no. K-44-14-15 (virtually the same site as the type), 04.VIII.2015, leg. Bakalin V. A. ( VBGI). — Switzerland. Canton de Valais, Val d’Arpette, near Champex, 46°01’44”N, 07°05’24”E, 1700-2200 m alt., wet stone, field no. Sw-48-2-13, 28.IX.2013, leg. Bakalin V. A. ( VBGI, MW). — Japan. Honshu, Yamanashi Prefecture, eastern slope of Senjo-ga-dake Mt., 35°45’46”N, 138°11’19”E, 2600 m alt., Abies -Tsuga diversifolia mountain forest in the valley, field no. J-89-31-15, 2.X.2015, leg. Bakalin V. A. ( VBGI, MW).

DESCRIPTION

Plants greenish brownish to rusty, without distinct purple pigmentation, 5-20 mm long and 0.8-1.3 mm wide, merely soft. Rhizoids sparse, brownish, present in basal part of perianthous shoots only, obliquely spreading or united into unclear fascicles. Stem yellowish greenish to brownish, branching not seen (probably due to free sporophyte production and distribution by spores within cushions even); cross section transversely elliptic, c. 200 × 250 Μm, hyaloderm distinct due to larger cells, but cell walls are thickened, 15-20 Μm along margin, scleroderma distinct, cell walls thickened, colorless, 11-15 Μm in diameter, gradually becoming thinner to the middle. Leaves transversely inserted, shortly (to ⅓ of stem width) decurrent dorsally, transversely or arcuately inserted ventrally, loosely or not sheathing the stem, leaf margin plane or revolute (large leaves) in lower half of leaf only, concave-canaliculate, obliquely spreading, when flattened in the slide suborbicular to loosely ovate, 0.5- 1.0 × 0.6-1.1 mm, divided by gamma- or widely V-shaped sinus into two subequal or slightly unequal (dorsal smaller) lobes with rounded to obtuse apices. Midleaf cells 12-30 × 12-18 Μm, walls slightly thickened, trigones convex, moderate in size; cells in the base of lobe middle 10-17 × 10-15 Μm, nearly thin-walled, trigones moderate to large in size, convex to triangular; cells along leaf margin 9-14 Μm, slightly thick-walled, trigones moderate in size, concave (adjacent to external side) to slightly convex; cuticle smooth throughout; oil bodies in the midleaf cells relatively small, spherical to oblong, 2-7 × 2-4 Μm, 2-3 per cell, grayish bluish, very finely granulate. Dioicous. Androecia intercalary, with 10-15 and more pairs of bracts, unfrequently becoming to sterile branch or die. Perianth conical, loosely beaked, 0.2-0.3 × 0.6 mm, perigynium robust, 0.8-1.2 mm high, with 2 pairs of bracts; female bracts in lower pair sheathing the perigynium in the base and obliquely to erect spreading above and sometimes loosely reflexed, the axis of the upper pair of bracts subparallel to the stem and cover the perianth. Elaters bispiral, c. 100 × 7 Μm. Spores brown, finely papillose, 10-12 Μm in diameter.

Figures

FIG. 2. — Marsupella subemarginata Bakalin & Fedosov,sp. nov.:A, B, perianthous plants, dorsal view;C, male branch, dorsal view;D, sterile branch, dorsal view; E-H, leaves. Types: A, from holotype K-44-16-15, VBGI; B-H, from paratype K-44-14-15, VBGI. Scale bars: A, 1 mm; B-D, 1 mm; E-H, 1 mm.