Metzgeria leptoneura Spruce (1885: 555)

Sukkharak, Phiangphak & Chantanaorrapint, Sahut, 2020, The liverwort genus Metzgeria (Metzgeriaceae, Marchantiophyta) in Thailand, Phytotaxa 441 (3), pp. 251-262 : 257

4. Metzgeria leptoneura Spruce (1885: 555) ( Fig. 4 )

Type: — PERU. “in monte Campana andium, Spruce s.n. ” (holotype MANCH; isotypes F, G, W) ( So 2003).

Thallus dioicous, up to 2.9 cm long, 0.7–1 mm wide, dichotomously branched, appressed to the substrate to convex dorsally, margins strongly recurved, light green. Thallus apex slightly obtuse. Hairs double, strongly curved, numerous; 2 rows on ventral side of midrib. Midrib in cross section orbicular, 141–146 × 98–103 µm, composed of 2 cells wide on both dorsal and ventral sides, 20–25 medullary cells, dorsal epidermal cells 18–20 × 46–50 µm, ventral epidermal cells 61–63 × 38–41 µm, medullary cells 13–33 × 11–21 µm. Wing 14–24 cells wide; marginal cells 50–66 × 23–33 μm, median cells 45–73 × 21–41 μm. Oil bodies not seen. Antheridial branches spherical, 0.2–0.3 × 0.2–0.4 mm, midrib present, without hair. Female involucres obovate, 0.1–0.2 × 0.2–0.3 mm, with hairs along margin, on outer surface. Capsule spherical, valve 0.1–0.3 × 0.5–0.7 mm. Elaters spiral, brown, 250–370 × 5–7 μm, with a single helicoidal band of thickenings. Gemmae at apex and margin of branches.

Additional illustrations: — Kuwahara (1958: Figs. I2 , II5, 12, V10–20 as M. hamata ; 1960: Fig. 5a–f as M. parvipapulosa , Fig. 10k, l as M. hamata ; 1966: Fig. 1a–g as M. hamata ; 1968a: Fig. 2 as M. iwatsukii ; Fig. 7 as M. sharpii ; 1969c: Pl. 94d as M. renauldii ); Piippo (1991: Figs. 9, 11–12, Figs. 5 , 7d–i as M. australis ); Stephani (1985: Icon. n. 7552 as M. allanii , n. 7565 as M. recurva , n. 7566 as M. renauldii , n. 7579 as M. leptoneura , n. 7645 as M. curviseta , n. 7663 as M. longipila , n. 7671 as M. papulosa , n. 7676 as M. sandei , n. 7678 as M. atrichoneura , n. 7679 as M. colensoi ); So (2003: Fig. 3d ).

Ecology: — Metzgeria leptoneura in Thailand is collected from branches, branchlets, twigs, tree trunks, base of trees, fallen trees, logs, moist soil, and mixed soil, roadside bank in hill evergreen forest, evergreen forest along stream, mossy hill evergreen forest rich in Ericaceae , moist area of dense forest with partial shade light, moist area of open forest with partial light at the altitude ranging from 700–2570 m.

Specimens examined: — THAILAND. Chiang Mai: Doi Pui , 18 Novermber 2004, Santanachote 287 ( CMUB) ; 11 December 2005, Santanachote 511 ( CMUB).— Doi, Inthanon , 18°35’ N 98°30’ E, 18 December 1965, Touw 9702, 9707, 9736 ( BKF) ; 18°33’ N 98°29’ E, 20 January 2010, Akiyama, Irie, Printarakul & Kanzai 1322 ( BKF) ; 17 January 2010, Printarakul 2818, 2873 ( CMUB) ; Ang-ka , 31 December 1974, Patanapolpaiboon s.n. ( BCU) ; 14 December 1978, Thaithong 826 (2 packages), 802, 833, 845, 851, 855, 860, 939 ( BCU) ; 9 August 2005, Santanachote 510 ( CMUB) ; 9 March 2011, Printarakul 3601, 3621 (2 packages) ( CMUB) ; 15 April 2012, Printarakul 5255 ( CMUB) ; Doi Hua Suea , 18°29’ N 98°33’ E, 27 October 2018, Kraichak 1754 (hb. Kasetsart Univ.) ; Kew Mae Pan Nature Trail , 18°33’ N 98°28’ E, 28 October 2018, Kanjananuch 20 (hb. Kasetsart Univ.). Trat: Koh Chang, 30 December “1974”, Jintana, Ariya, Suwanna s.n. ( BCU). Nakhon Si Thammarat: Khao Luang, 8°30’ N 99°45’ E, 7 February 1966, Touw 12005 ( BKF).— Khao Nan National Park, Khao Nan Yai, 13 March 2006, Sukkharak 206 ( BCU) .

Distribution: —Worldwide ( Zhu & So 2001; So 2003).

Notes: —The species characterized by 1) strongly decurved thallus margin, 2) marginal hairs of thallus strongly falcate and hooked, usually in pairs, and 3) ventral epidermal cells of midrib very large and protruding, triangular in cross-section.

Figures

FIGURE 1. Metzgeria consanguinea. A. Part of thallus with attenuated apex and gemma, dorsal view; g = gemma. B. Part of thallus with attenuated apex and gemma, ventral view; g = gemma. C. Part of thallus with obtuse apices, dorsal view. D. Part of thallus with obtuse apices, ventral view. E. Part of female thallus with involucres, ventral view. F. Marginal cells of wing and hairs, ventral view. G. Median cells of wing, dorsal view. H. Midrib and median cells of wing, dorsal view. I. Cross section of thallus. [A–E, G–I from Sukkharak 202/1230 (hb. Burapha Univ.); F from Sukkharak 168/1212 (hb. Burapha Univ.)].

FIGURE 2. Metzgeria furcata. A. Part of thallus, dorsal view. B. Part of thallus, ventral view. C. Part of female thallus with involucres and adventitious shoot, ventral view; a = adventitious shoot. D. Marginal cells of wing and hairs, ventral view. E. Median cells of wing, dorsal view. F. Midrib and median cells of wing, dorsal view. G. Cross section of thallus [All from Sukkharak 121/1197 (hb. Burapha Univ.)].

FIGURE 3. Metzgeria kinabaluensis. A. Part of thallus, dorsal view; B. Part of thallus, ventral view. C. Part of male thallus with antheridial branch, ventral view. D. Marginal cells of wing and hairs, ventral view. E. Median cells of wing, dorsal view. F. Midrib and median cells of wing, dorsal view. G. Cross section of thallus [All from Chantanaorrapint & Suwanmala 3890 (PSU)].

FIGURE 4. Metzgeria leptoneura. A. Part of thallus, dorsal view. B. Part of thallus, ventral view. C. Part of male thallus with antheridial branches, ventral view. D. Part of female thallus with involucres and sporophyte, ventral view. E. Part of thallus with gemmae and adventitious shoots, ventral view; g = gemma, a = adventitious shoot. F. Cells of thallus apex with mucilage, ventral view. G. Marginal cells of wing and hairs, ventral view. H. Median cells of wing, dorsal view. I. Midrib and median cells of wing, dorsal view. J. Cross section of thallus. K. Elaters. [All from Akiyama, Irie, Printarakul & Kanzai 1322 (BKF)].

FIGURE 5. Metzgeria lindbergii. A. Part of thallus, dorsal view; B. Part of thallus, ventral view. C. Part of thallus with antheridial branches, involucres, calyptra, and sporophyte, ventral view. D. Marginal cells of wing and hairs, ventral view. E. Median cells of wing, dorsal view. F. Midrib and median cells of wing, dorsal view. G. Cross section of midrib. H. Elaters. [All from Sukkharak 161/1210 (hb. Burapha Univ.)].