Lophocolea savesiana Steph.

Thouvenot, Louis, 2023, A taxonomic revision of the Lophocoleaceae Vanden Berghen (Marchantiophyta) of New Caledonia, Cryptogamie, Bryologie 20 (1), pp. 1-60 : 48

Lophocolea savesiana Steph.

( Fig. 28 )

Species Hepaticarum 3: 122 ( Stephani 1906). — Chiloscyphus savesianus (Steph.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 422 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. Savès s.n. (lecto-, here designated, fide Kitagawa 1969 in sched. G [Nouméa, 1887, Savès s.n., G00061342 ]!).

DISTRIBUTION IN NEW CALEDONIA. — Only known from the type (“Nouméa”).

TOTAL RANGE. — Endemic.

DESCRIPTION

Dioecious.

Habit

Medium plants with shoots 2.50 mm wide when flattened; leaves imbricate, 1/3 overlapping, horizontally spreading at right angle, slightly convex, alternate but slightly so, seeming subopposite, dorsally free, dorsal insertion separated by four cell rows.

Leaves

Oblong to trapezoid, margins nearly parallel below middle then width progressively decreasing in upper part or ventral margin nearly orthogonal to the stem and dorsal margin oblique, 1.00- 1.20 mm long, 0.60-0.90 mm wide near base, 0.35-0.45 below apex, leaf apices truncate, flat to slightly concave with a single tooth at both angles, acute, (1-)3(-4) cells long, leaf margins entire.

Cells

Hexagonal, (25-)30-40 µm, thin-walled, without trigones.

Underleaves

Small, as wide as stems, narrowly connate to both nearest leaves, connation 1-3 cells wide, insertion in an inverted U, apices deeply bifid with lunate sinus, discs arched, narrow, usually two cells high, nine cells wide, lobes linear lanceolate, each lateral margins with a single short to filiform tooth.

Gametangia

Male and female gametangia set at apices of main shoots or long branches with normal leaves; gynoecia with two pairs of bracts, bract shapes like the normal leaves but larger, 1.8 mm long, ventral margins with one tooth, bracteoles oblong, margins toothed with 3-4 strong teeth in upper part; perianths oblong, cupulate at base, trigone in upper part, not winged, mouth shallowly 3-lobed, the lobes strongly toothed, acute teeth triangular to lanceolate; androecia with up to eight pairs of bracts.

COMMENTS

The type specimen at G is copiously fertile with both kinds of gametangia and the dioecious condition is likely since no connection between the male and female shoots could be noted. Superficial view could lead to assign this species to the genus Heteroscyphus considering the shape and nearly subopposite insertion of the leaves and it may be closer to Heteroscyphus etesseanus which has similar leaves, underleaves and cells, but the gametoecia locations and shapes separate them as well as some vegetative characters, H. etesseanus having smaller size, with shoots 1.50 mm wide when flattened, and leaves contiguous to distant. Lophocolea savesiana has gametangia as in Lophocolea , set at the end of long normal-leaved shoots, oblong perianths that are conspicuously trigonous in upper part, and androecial bracts smaller than normal leaves, in series of 8 pairs. The species may be compared with L. convexula , but the latter is smaller with ovate leaves that are strongly narrowed to the apex, and with bulging leaf cells making the leaf margins crenulate. The species also resembles Heteroscyphus parapilistipulus but the latter species is a larger plant with shoots up to 4.5 mm wide, leaves rather oval and gynoecia and androecia on short leafless lateral branches.

Figures

FIG. 28. — Lophocolea savesiana Steph.: A, shoot portion, ventral view; B, adjacent leaves, dorsal view; C, underleaves; D, top part of a male shoot, dorsal view; E, perianth;F, H, teeth at leaf apex angles;G, median cells.All illustrated from the lectotype (G00061342). Scale bars:A,B, D,E, 500 µm;G,50 µm;C,F,H, 100 µm.