Lethocolea javanica (Schiffn.) Grolle

Gradstein, S. Robbert, Ilkiu-Borges, Anna Luiza, Cargill, D. Christine, Beckmann, Karen & Vanderpoorten, Alain, 2024, An integrative taxonomic study of the genus Lethocolea (Marchantiophyta: Acrobolbaceae), Plant Ecology and Evolution 157 (3), pp. 375-398 : 375-398

2. Lethocolea javanica (Schiffn.) Grolle ( Grolle 1965: 83)

Figs 3 , 4 , 5

Symphyomitra javanica Schiffn. ( Schiffner 1898: 193) – Type: same as for Lethocolea javanica.

Gongylanthus leratae Steph. ( Stephani 1922: 257), syn. nov. – Type: New Caledonia – Ile des Pins • “ De la 3 e à la 4 e commune par la Baie puante ”; May 1909; c. marsup. & andr.; L. Lerat 67; lectotype (designated here): G [ G 00067194 ]; isolectotype: JE • “ Route de Wahehia à la Mission ”; Jun. 1909; L. Lerat 74; syntype: G [ G 00051144 ].

Type.

Indonesia – West Java • “ Pov. Preanger. In Cinchoneto “ Daradjat ” prope Garut ad terram. Regio nubium ”; ± 1730 m; 2 Feb. 1894; c. marsup.; V. Schiffner 499; lectotype (designated here): FH [ FH 01122545 ]; isolectotypes: G [ G 00064407 ], JE .

Description.

Plants dioicous, 1–2 cm long, 0.5–2 mm wide, prostrate, somewhat dull-coloured (due to the densely papillose cuticle), pale green to olive green to light brown (shaded sites) or carmine red (exposed sites), shoots in strongly exposed sites worm-like with densely imbricate leaves, in shaded sites more flattened and with spreading, less densely imbricate leaves, stolons usually absent, when present located near the base of the shoot, leafy branches and innovations not observed. Stems ca 0.2–0.4 mm in diameter, fragile or rigid; dorsal surface green, ventral surface green or purplish-reddish; epidermal and medullary cells similar in size of the epidermal cells slightly smaller ( Schuster 2021, as L. pansa ), all cell walls thin (stems fragile) or walls of the epidermal cell walls slightly thickened (stems rigid). Rhizoids scattered, hyaline to light brown (to reddish or pink; Schuster 2021), with thin walls, sometimes with fungal hyphae. Leaves succubous, imbricate, unpigmented to partially or almost entirely brown to reddish pigmented, obliquely to widely spreading, subvertically arranged and appressed to spreading outwards or obliquely to widely spreading outwards, flat to convex to concave with convex margins, ovate-orbicular to broadly ovate to ovate-oblong (1.0–1.7: 1), apex broadly rounded, margins entire, dorsal and ventral bases not or slightly decurrent. Leaf cells in the upper and dorsal part of leaf rounded-isodiametrical to slightly elongate, ca 20–30 µm in diameter, towards the margin similar in size or smaller, subquadrate, border of thicker-walled cells lacking, cells in the lower central and ventral part of the leaf distinctly enlarged, becoming 2–3 × larger and more hyaline than in the upper part of leaf, isodiametrical to elongate, 1–4 (– 7) × longer than wide, becoming increasingly elongate towards the lower ventral margin; cells with distinct trigones, the trigones 3–8 µm in diameter, fully hyaline, sometimes reddish, with concave to slightly bulging sides, sometimes seemingly vanishing towards the ventral base, in the enlarged cells; cuticle of dorsal and ventral surface of leaf covered by low, hyaline, rounded to elongate papillae, the papillae becoming progressively more elongate towards the leaf base and sometimes rather inconspicuous in older herbarium material, when rounded ca 3–6 µm in diameter, cuticle at leaf margin smooth or with low papillae; oil bodies one per cell, greyish-brown, sometimes persistent in old herbarium material, finely papillose and sometimes with 1–2 pupils (“ eye spots ”), spherical to ellipsoid, 8–20 (– 25) µm long, ca 1 / 3–1 / 2 the length of the cell-lumen in the upper half of the leaf, in the lower half of the leaf cells only ca 1 / 5–1 / 4 the length of the lumen in the enlarged leaf cells. Underleaves not observed ( Schuster 2021: occasionally present on some stems, ovate-elliptical to ligulate). Androecia with 5–6 pairs of bracts, bracts saccate, antheridia one per bract. Gynoecia as in L. pansa . Marsupia up to 10 (– 20) mm long, sometimes shorter (only ca 2.5 mm long in Pócs 01113 / A from northern Queensland), outer surface hairy, wall 5–6 cells thick, marsupial canal lined by numerous large, somewhat clavate, papilliform cells, the cells up to 75 µm long, 13–20 µm wide, protruding from the mouth of the marsupium. Sporophytes ( Schuster 2021) foot massive, with an extensive haustorial collar; seta long and slender; capsule narrowly cylindrical, hardly wider than the seta, slightly pointed or beaked at apex, opening by four valves. Gemmae positioned on the dorsal stem surface near the shoot apex, pale green, orbicular to slightly elongate, 4–10 (– 15) cells across, pale green to yellowish-brown, biconvex, centre up to 6 cells thick, towards the margin transparent, forming a 1 (– 2) cell wide unistratose wing, outer margin crenulate to irregularly crenate due to angularly protruding cells. Gemmalings originating from the margin of the gemmae.

Distribution.

Australasia ( Australia, New Zealand, New Caledonia), Indonesia (Java), southern India (Kerala: Nilgiri Hills, Tamil Nadu). In Indonesia, L. javanica is known from two old collections from Java; its occurrence on soil along trails suggest that the species should be more common in Indonesia and has been overlooked. The true distribution of L. javanica and L. pansa in Australia and New Zealand requires more study and is beyond the limits of the present study. For the occurrence of L. javanica in India see Udar and Kumar (1986) and Alam (2014).

Habitat.

Lethocolea javanica grows on shaded and exposed sandy, loamy, or peaty soil, or soil over rock which dries out periodically, in rather xeric to humid vegetation, often along trails or water courses, from almost sea level to ca 1000 m in Australasia, and at 1700–2000 m in tropical Asia. In New Caledonia, the species occurs on basic, serpentine soil (pH 5–6) in maquis-type vegetation.

Additional material examined.

Australia – Australian Capital Territory (A. C. T.) • Canberra, Canberra National Herbarium , greenhouse collections; Cargill 1772; CANB • Canberra, Canberra National Herbarium , greenhouse collections; Purdie 12476; CANB . – New South Wales • Jimberoo State Forest, 11 km NNE of Rankin Springs ; Curnow 3376; CANB [ CANB 9404956 ] • Cottan-Bimbang National Park, 0.5 km from Cells and 3 km from Oxley Highway ; c. gemm.; Curnow 6163; CANB [ CANB 889563 ] • 19 km from Batemans Bay on Braidwood Road ; 300 m; Streimann 970; CBG [ CBG 054175 ] • Weddin Mountain National Park, 16 km SW of Grenfell ; Streimann 49251; CBG [ CBG 9213766 ] . – Northern Territory • NE Arnhem Land, Gore, Rindarry Creek ; 40 m; Russell-Smith 4829; JE . – Queensland • Paluma Range, forest road 1–2 km N of Mt. Zero ; 950 m; c. marsup.; Pócs 01113 / A; GOET • Paluma Range, along Taravale forest road E of Mt. Zero ; Cargill 165; CANB [ CANB 644649 ] . – Western Australia • Darling Range, forest at Martin , Mills Road , 22 km SE of Perth ; Curnow 4793; CBG [ CBG 9512491 ] • D’Entrecasteaux National Park, 315 km S of Perth ; Cargill 722; CANB [ CANB 759070 ] .

New Zealand – North Island • “ Forests of Titiokura ” ( Mitten 1854); c. marsup.; Colenso 3681, syntype of Gymnanthe drummondii Mitt. ; NY [ NY 04461793 ] • Taupo ; c. marsup.; Berggren 3141; NY [ NY 04461794 ] • Near Atiamuri; 1200 ft.; oil bodies persistent; Allison H 259; JE • Hawkes Bay, Wairoa, Kiwi Valley ; c. marsup.; Hodgson 6454; JE • Unuwahu bush ; 300 m; Bartlett 2-79 - 4; JE • Ahipara ; 200 m; Bartlett 195; JE •

New Caledonia – Grand Terre • Mont-Dore, near bifurcation of road Yaté – Plum ; ca 100 m; c. andr.; Hürlimann 2001; GOET, PC • same data as for preceding; Hürlimann 2002; GOET, PC • East of Yanna valley near St. Louis ; ca 150 m; Hürlimann 2013; GOET • same data as for preceding; Hürlimann 2033; GOET • Valley of Pouéta Kouré above La Coulée ; 55 m; Hürlimann 2035; GOET, PC • Crest of Koghis Mts, SE of Mt. Bouo ; 710 m; Hürlimann 2127; GOET, PC • Mt. des Sources ; ca 800 m; Hürlimann 2354; GOET, PC • Dumbéa, near “ Sunshine ” mine ; ca 650 m; c. gemm., oil bodies persistent; Hürlimann 2409; GOET .

Indonesia – Java • Central Java, Salangan ; 1924; c. gemm.; Goebel s. n.; JE .

Notes.

Lethocolea javanica is recognized by the densely papillose cuticle, distinct trigones in the middle and upper part of the leaves, and winged gemmae with a crenulate to crenate margin of slightly to strongly and angularly protruding cells. In Australasia, the species has previously been called L. pansa (e. g. Engel and Glenny 2019; Schuster 2021), but the latter species has a smooth cuticle, minute trigones, and wingless gemmae with a crenulate margin of slightly and regularly bulging cells that are not protruding angularly (Figs 3 – 5 ). The status of the two species is confirmed by the molecular analysis (Fig. 2 ). The detailed description and illustration of L. pansa in Engel and Glenny (2019) is a mixture of L. pansa and L. javanica . In older herbarium material, the papillae of L. javanica may sometimes become somewhat inconspicuous and some authors have described the cuticle as being smooth (e. g. Schiffner 1900; but see Stephani 1901). Schiffner (1898) also suggested that trigones are absent in the type of L. javanica (“ Trigonis nullis ”), but we observed distinct trigones in the type material.

Figures

Figure 2. Maximum likelihood tree resulting from rps 4 sequences in the liverwort genus Lethocolea. Numbers below the branches correspond to bootstrap support.

Figure 3. Cuticle and oil bodies in Lethocolea, SEM. A, D. Papillose cuticle of L. congesta. B. Smooth cuticle of L. pansa. C. Papillose cuticle of L. javanica. E – F. Oil bodies of L. javanica. G – H. Oil bodies of L. congesta. A, D from Larrain 42566; B from Arts 129 / 11; C, E – F from Beckmann (unpublished thesis work, 1985); G – H from from Arts 19 / 54. Photos: A – B, D by Anna Luiza Ilkiu-Borges; C, E – F by Karen Beckmann; G – H by Christine Cocquyt and Robbert Gradstein.

Figure 4. Leaf cells and habit of Lethocolea javanica and L. pansa. A – B. Midleaf cells of L. javanica, showing large trigones. C. Leaf margin cells of L. javanica, showing papillae. D – E. Midleaf cells of L. pansa, showing trigones absent or very small. F. Habit of L. pansa (wetted herbarium material). A – B from Cargill 166; C from Docherty 2; D from Purdie 8216 A; E from Curnow 6597 A; F from Purdie 8216 A. Photos by D. Christine Cargill.

Figure 5. Gemmae of Lethocolea javanica and L. pansa. A – E. Winged gemmae of L. javanica. F – J. Wingless gemmae of L. pansa. A from Streimann 970; B – D from Streimann 49251; E from Curnow 6163; F from Curnow 6871; G from Purdie 8216 A; H from Curnow WA 118; I from Curnow 6567; J from Streimann 54953. Photos by D. Christine Cargill.