Thysananthus convolutus Lindenberg

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

6. Thysananthus convolutus Lindenberg in Gottsche et al. (1845: 288). Jungermannia spathulistipa γ Nees (1830: 38) , nom. inval. Lejeunea (subg. Thysanolejeunea) convoluta (Lindenb.) Spruce (1884: 106) . Thysanolejeunea convoluta (Lindenb.) Stephani (1890: 142) , nom. inval. Lectotype (here designated): INDONESIA. Java: “Habitat in Javae montosis, v.c. in monte Leback Provinciae Bantam, frequens,” Blume s.n. (lectotype STR!; isolectotypes BM!).

Thysananthus subreversus Stephani (1912a: 791) . Type: PAPUA NEW GUINEA. Morobe: “Kaiser Wilhelmsland: Sattelberg”, “1899”, Nyman s.n. (isotype S!); Icon. Steph. nr. 10218.

Plants dioicous, with projecting growth, turning upwards and becoming ascending to erect, pale green, becoming dark brown to blackish in the older portion in the field, reddish brown in the older portions in herbarium specimens, up to 7 cm long × 1.4–2.2 mm wide. Stems rather rigid; ventral merophyte 7–10 cell rows wide; stem in cross section orbicular, 125–297 µm high × 120–262 µm wide, 8–16 cell layers high, composed of 23–49 epidermal cells surrounding 41–156 medullary cells, epidermal cells as large as medullary cells. Leaves strongly imbricate, when dry suberect and strongly convolute, when moist strongly convex, apical part turn to ventral side, recurved; dorsal lobe asymmetrically broadly ovate to ovate, 0.9–1.3 × 0.8–1.4 mm, apex mucronate-apiculate, dorsal base auriculate, auricle 130–215 × 75–150 µm, dorsal margin with 4–16 triangular teeth, the teeth consisting of 3–8 cells, being 2–3 cells wide at base and ending in a row of 1–3 cells, ventral margin incurved 2/3 × leaf length with 4–6 triangular teeth, the teeth consisting of 3–5 cells, being 2–3 cells wide at base and ending in a row of 1–3 cells; cells elongate-hexagonal with acute ends, vitta absent, marginal cells 7–15 × 5–12.5 µm, median cells 20–42.5 × 5–12.5 µm, basal cells 25–67.5 × 12–25 µm, trigones cordate, often coalesced, intermediate thickenings 0–2 per cell; oil bodies 2–4 per cell. Lobules oblong-rectangular to rectangular, 0.3–0.4 × 0.1–0.3 mm, 1/4–1/3 × lobe length; appendage on surface of lobule base not developed; keel without appendage or with appendages on one side where leaves and underleaves are free and opposite to adnate ones, appendage always curved towards the stems; lobule apex oblique, free margin continuing into the ventral lobe margin, apex with 1–2 triangular teeth, the first tooth consisting of 4–6 cells, being 2–3 cells wide at base and ending in a row of 1–2 cells, the second tooth of one cell only, often absent. Underleaves imbricate, slightly squarrose, broadly obovate-spathulate to spathulate, 0.5–1 × 0.4–0.7 mm, 1–5 × stem width, apex truncate to rounded, plane, incurved, or strongly recurved, margin with 12–20 triangular teeth, the teeth consisting of 3–4 cells, being 2 cells wide at base and ending in a row of 1–2 cells, bases cuneate, underleaf bases adnate with leaves on one side, on left-hand side for right branches and right-hand side for left branches; cells 12–27 × 5–10 µm. Androecia terminal-intercalary on lateral branches, bracts and bracteoles in 3–4 pairs, bracts hypostatic, 0.9–1 × 0.7–0.8 mm, apex acute, margins entire; antheridia 2 per bract. Gynoecia with one lejeuneoid innovation forming a monochasial pattern; lobe broadly ovate, 1.5–1.9 × 9– 1.4 mm, apex apiculate, margin in upper 1/3 with 8–19 triangular teeth, the teeth consisting of 3–7 cells, being 2–3 cells wide at base and ending in a row of 1–3 cells; lobules broadly ovate, 1/2 × lobe length, apex apiculate to obscurely bifid, margins with triangular teeth, the teeth consisting of 3–10 cells, being 2–4 cells wide at base and ending in a row of 1–3 cells; bracteoles spathulate, 1.3–1.8 × 0.7–1.2 mm, apex slightly emarginate, 1/3–2/3 × bracteole length with triangular teeth, the teeth consisting of 3–9 cells, being 2–3 cells wide at base and ending in a row of 1–3 cells, margins recurved. Perianths oblong-cylindrical or obovate, 1.5–2.5 × 0.7–1 mm long, keels in upper 1/3 with triangular or laciniate teeth, the teeth consisting of 4–8 cells, being 2–3 cells wide at base and ending in a row of 1–6 cells; beak 38–87 µm (3–5 cells) in length or absent.

28 • Phytotaxa 193 (1) © 2015 Magnolia Press

SUKKHARAK