Gymnomitrion noguchianum S.Hatt., J. Jap. Bot. 27: 55, 1952

Bakalin, Vadim, Choi, Seung Se & Park, Seung Jin, 2021, Revision of Gymnomitriaceae (Marchantiophyta) in the Korean Peninsula, PhytoKeys 176, pp. 77-110 : 77

Gymnomitrion noguchianum S.Hatt., J. Jap. Bot. 27: 55, 1952 Figure 7A-H

Type.

Japan. Tottori Prefecture, Daisen Mt. , 1400 m, on volcanic rocks, 8 August 1947, A. Noguchi s.n. (holotype: NICH [13067!]) .

Description.

Plants in loose mats, more or less soft, leaved part of shoots distinctly clavate from rhizomatous base, dorsiventrally compressed, whitish to whitish green or almost completely white, immersed to soil and incrusted by soil particles, 250-350 μm wide and 500-700 μm long in leaved part, rhizomatous part ca. 3-5 mm long. Rhizoids common to (in rhizomatous base) dense, erect to obliquely spreading, separated or in unclear fascicles. Stem freely ventrally branched in the base of leaved part and variously and feely branched in rhizome; slightly transversely elliptic in cross section, ca. 100 μm high and 120 μm wide, without evident differentiation into layers, outer cells 12-15 μm along margin, with thick walls (become noticeable thinner to thin in ventral epidermis), with moderate in size, concave trigones, inner cells 7-13 μm in diameter, irregular in shape, with thickened walls and moderate to small in size concave trigones. Leaves densely imbricate, transversely inserted, not sheathing at base, transversely oriented, widely ovate-lingulate to widely triangular, cupped to spoon shaped, lacerate when flattened, 220-330 μm long and 270-500 μm wide, with rounded to emarginate apex and entire to crenulate margin. Cells in the midleaf subisodiametric (mostly quadrate) to oblong (mostly rectangular), 12-25 × 12-20(23) μm, walls thickened, trigones small to moderate in size, concave, cuticle smooth; cells along leaf margin 5-15 μm, mostly elongate perpendicularly to the margin, walls unequally thickened, trigones small to moderate, concave. Dioicous. Androecia intercalary, with cupped and loosely imbricate bracts. Perianth and perigynium absent, perichaetial area of the shoot distinctly wider than below.

Ecology.

Acidophilic meso-xerophyte. The species occupies dry to mesic fine soils in well-exposed places at higher altitudes. It is commonly associated with dwarf xeric forms of Marsupella tubulosa , Gymnomitrion parvitextum , and Cephaloziella divaricata .

Distribution.

Temperate Montane Eastern Asian endemic species with distribution confined to Japanese Honshu and Kushu as well as the southern tip of Korea (Jeju Island).

Specimens examined.

Jeju-do: Mt. Halla , 33°21'51.0"N, 126°31'42.9"E, 1814 m, 7 Sep 2012, S.S. Choi 120809, 120812, 120826 (JNU) .

Comment.

Due to the presence of entire to emarginate leaves, Gymnomitrion noguchianum is unlikely to be mistaken for other members of this genus. However, it may be mistaken for Cryptocoleopsis imbricata , but that species is not yet known from the Korean Peninsula, though it should be expected to occur there. Both taxa are similar in prostrate growth, occurring in well-exposed places, and entire imbricate leaves. However, two taxa may be easily separated by 1) leaf cell walls are thickened and smaller in G. noguchianum , versus larger (more than 20 μm wide) and thin-walled in Cryptocoleopsis imbricata , 2) total absence of brown pigmentation in G. noguchianum versus almost constant presence in Cryptocoleopsis ; and 3) presence of calyptral perigynium in Cryptocoleopsis - the structure does not occur in Gymnomitrion .

Figures

Figure 7. Gymnomitrion noguchianum S. Hatt. A, B, F leaves C plant habit (fragment) D plant habit E lacerate leaf apex G cells along leaf margin H stem cross section (fragment). All from Choi 120826 (JNU); Marsupella vermiformis (R. M. Schust.) Bakalin et Fedosov I, J leaves K plant habit (fragment). All from Choi 120911 (JNU). Scale bars: a 250 µm (A-C, F); a 500 µm (D); b 100 µm (E, G-J); c 100 µm (K).