Thysananthus retusus (Reinwardt, Blume & Nees) B.M. Thiers & Gradstein (1989: 67)

Sukkharak, Phiangphak, 2015, A systematic monograph of the genus Thysananthus (Lejeuneaceae, Marchantiophyta), Phytotaxa 193 (1), pp. 448-450 : 448-450

15. Thysananthus retusus (Reinwardt, Blume & Nees) B.M. Thiers & Gradstein (1989: 67) . Jungermannia retusa Reinwardt, Blume & Nees (1824: 214) . Type: INDONESIA. Java [“inter muscos Javae insulae, rarior”]: without date, Blume s.n. (holotype STR; isotypes S!, W 3 packets!).

Thysananthus planus Sande Lacoste (1855: 419) , syn. fide Thiers & Gradstein (1989): 67. Type: INDONESIA. Java: Junghuhn s.n. (holotype L!).

Thysananthus subplanus Stephani (1912a: 790) . Type: PHILIPPINES. Bataan: Mt. Mariveles , E.D. Merrill 3984 (holotype G!); Icon. Steph. nr. 10217.

Brachiolejeunea grossivitta Stephani in Stephani & Watts (1914: 10). Type : VANUATU [New Hebrides]. “Aneityum”, 1911, Gunn s.n. (isotype JE!).

Mastigolejeunea acutifolia Stephani in Stephani & Watts (1914: 125). Lectotype (here designed): VANUATU, ''Insulae Novae Hebridae (Santo: Bowie leg.; Aneityum: Gunn leg.)", Watts 33 (lectotype G!), Icon. Steph. nr. 7409, syn. nov.

Thysananthus furcatus Herzog (1931: 87) . Type: PHILIPPINES. Benguet: “ Baguio, 20.V.15, C. J. Baker (n. 7004) n. 7053 ” (syntype JE!).

Thysananthus flavescens (S.Hatt.) Gradstein (1991: 13) . Archilejeunea flavescens Hattori (1944: 95) . Leucolejeunea flavescens (S.Hatt.) Hattori (1952: 33) . Mastigolejeunea flavescens (S.Hatt.) Mizutani (1961: 159) . Type: JAPAN. Osumi: Sata-mura, Hetka, on bark, 18 April 1939, S. Hattori 2399 (isotype NICH!), syn. nov.

Thysananthus australis (Steph.) Thiers & Gradstein (1989: 66) . Archilejeunea australis Stephani (1912a: 734) . Type: AUSTRALIA. New South Wales: Back of Wickham’s farm near Ballina, on tree, 3 June 1902, W. W. Watts 415 (holotype G!), syn. nov.

Plants autoicous, with projecting growth, turning upwards and becoming ascending to erect, dull green in the field, yellowish to reddish brown in herbarium specimens, up to 2 cm long × 1–2.5 mm wide. Stems rather fragile, ventral merophyte 6–9 cell rows wide; stem in cross section orbicular, 80–125 µm high × 85–98 µm wide, 7–10 cell layers high, composed of 16–21 epidermal cells surrounding 24–34 medullary cells, epidermal cells as large as medullary cells. Leaves contiguous to slightly imbricate; when dry wide spreading and flat, dorsal lobe symmetrically ovate to ligulate, 0.7–1.5 × 0.3–0.6 mm, apex acute-shortly apiculate, margins entire, dorsal base cordate, ventral margin plane; non-vittate cells subisodiametric to isodiametric, vitta present in midportion of lobe, extending to base, 2/3 × lobe length, 4–6 cell rows wide, 12–18 cells long, marginal cells 3–7 × 3–7 µm, median cells 10–15 × 7–12 µm, vitta 30–52 × 10–15 µm, vitta trigones coalesced, intermediate thickening 1–2(–3) per cell, non-vittate cells trigones and intermediate thickening faint; oil bodies 3–5 per non-vittate cell and 4–8 per vitta. Lobules oblong, 0.2–0.4 × 0.1–0.2 mm, 1/4–1/2 × lobe length; appendage on surface of lobule base on both sides of stem; keel without appendage; lobule apex oblique, free margin continuing into the ventral lobe margin, apex with one linear tooth, the tooth consisting of 4–5 cells, being 2–3 cells wide at base and ending in a row of 1–6 cells. Underleaves slightly imbricate, slightly squarrose, obovate, 0.3–0.6 × 0.2–0.5 mm, 2–5 × stem width, apex truncate to emarginate, recurved, margin entire, base cuneate, underleaf bases free or adnate with leaves on one side, on left-hand side for right branches and right-hand side for left branches; cells 10–15 × 3–7 µm. Androecia terminal-intercalary on lateral branches, bracts, and bracteoles in 3–10 pairs, bracts hypostatic, 0.9–1 × 0.3–0.4 mm, apex acute to apiculate, margins entire, antheridia 2 per bract. Gynoecia with 1–2 lejeuneoid innovations forming a monochasial or dichasial pattern or both; lobe ligulate, 1.6–1.7 × 0.6–0.7 mm, apex apiculate, margins entire or in upper 1/3 with triangular teeth, the teeth consisting of 3–5 cells, being 2–3 cells wide at base, apex of one cell; lobules broadly ovate, 1/3–1/2 × lobe length, apex apiculate to obscurely bifid, with triangular teeth, the teeth consisting of 3–5 cells, 2–3 cells wide at base and ending in a row of 1–2 cells; bracteoles ligulate, 0.9–1.4 × 0.3–0.6 mm, apex bifid, entire or toothed along margins, the teeth consisting of 3–7 cells, being 2–3 cells wide at base, apex of one cell, slightly recurved at base, margins plane. Perianths obovate, 0.8–1× 0.4–0.6 mm, keels in upper 1/3 with triangular teeth, the teeth consisting of 3–5 cells, being 2 cells wide at base, apex of one cell; beak 30–45 µm (3–5 cells) in length. Figs. 27–28A, C–E .

Figures

FIGURE 27. Thysananthus montanus Gradst., X.-L. He & Piippo. A. Portion of shoot, ventral view. B. Leaves, ventral view. C. Underleaves, ventral view. D. Female bracts, ventral view. E. Female bracteole. F. Perianth, dorsal view. G. Perianth, ventral view. H. Leaf apices. I. Margin cells of leaf lobe. J. Median cells of leaf lobe. K. Basal cells of leaf lobe. L. Leaf lobule apex. M. Cross section of stem. (All from the holotype).

FIGURE 28. Thysananthus retusus (Reinw., Blume & Nees) B.M.Thiers & Gradst. A–C. Portions of shoot, ventral view. D. Leaves, ventral view. E. Underleaves, ventral view. F. Female bracts, ventral view. G. Female bracteole, ventral view. H. Perianth, dorsal view. I. Perianth, ventral view. J–L. Leaf apices. M. Margin cells of leaf lobe. N. Median cells of leaf lobe. O. Basal cells of leaf lobe, showing the vitta. P–Q. Leaf lobule apices. R. Cross section of stem. S. Oil bodies, non-vittate cells. T. Oil bodies, vittate cells. (A–R from the holotype; S–T from Sukkharak 733 (BKF, GOET)).