Lejeunea gradsteinii is described and illustrated as a new species from Mt. Kinabalu, Sabah. The plant stands out by 1) lobules with flat free margin and 2 teeth, the first tooth consisting of (1)-2 cells, 2) whitish-green plant color, 3) weakly crenulate margins of leaves, underleaves, female bracts and bracteoles, 4) basal cells of leaf lobes forming a weak vitta, 5) well-developed trigones and scarce intermediate thickenings, 6) deeply bifid underleaves (to 2/3) with rounded tips, 7) long male shoots with up to 13 pair of bracts, and 8) longexserted, obovate-clavate perianths with 5 sharp keels ending into short auricles. Lejeunea gradsteinii is most closely related to L. kodamae Ikegami et Inoue and L. bidentula Herzog, all of which have 2-toothed lobules

Damanhuri, A.

Latiff, A.

Lee, G. E.

Pócs, Tamás

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29LEJEUNEA GRADSTEINII (LEJEUNEACEAE), A NEW LIVERWORT SPECIES FROM MT . KINABALU, SABAHLee G. E.1,T.Pócs2, A. Damanhuri1 & A. Latiff11 School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Selangor, Malaysia2 BotanyDepartmentofEszterházy College, EGER, Pf. 43. H-3301, Hungary 3301Lejeunea gradsteinii sp. nov.Lejeunea, endemics, Malaysia, Marchantiophyta, Mt. KinabaluAbstract: Lejeunea gradsteinii is described and illustrated as a new species from Mt. Kinabalu, Sabah. The plant stands out by 1) lobules with flat free margin and 2 teeth, the first tooth consisting of (1)-2 cells, 2) whitish-green plant color, 3) weakly crenulate margins of leaves, underleaves, female bracts and bracteoles, 4) basal cells of leaf lobes forming a weak vitta, 5) well-developed trigones and scarce intermediate thickenings, 6) deeply bifid underleaves (to 2/3) with rounded tips, 7) long male shoots with up to 13 pair of bracts, and 8) long-exserted, obovate-clavate perianths with 5 sharp keels ending into short auricles. Lejeunea gradsteinii is most closely related to L. kodamae Ikegami et Inoue and L. bidentula Herzog, all of which have 2-toothed lobules. IntroductionA whitish Lejeunea species with two teeth on the leaf lobule, one very distinct and the other weakly developed, was found on Mt. Kinabalu, Sabah, in the course of the ongoing revision of the genus Lejeunea (Marchantiophyta: Lejeuneaceae) in Malaysia (Lee et al. 2011a, 2011b). By the characteristic 2-toothed, never-reduced lobule the species did not match any of the Malaysian Lejeunea species studied thus far, all which have lobules with only one tooth and often being reduced. A 2-toothed lobule is otherwise also known only among Asian Lejeuneas in Lejeunea kodamae Ikegami et Inoue (Inoue 1961) and L. bidentula Herzog (Herzog 1930), and in some members of Papillolejeunea Pócs(see below). However, none of these matched the species from Mt Kinabalu. Other characteristic features of the species from Mt Kinabalu were the deeply bifid underleaves with rounded tips and, especially, the long first tooth of the lobule (2 cells long). By the latter character the species resembled the genus 30Papillolejeunea Pócs(Pócs1997;thisgenuswasreducedbySchuster1998toasubgenus of Lejeunea [as Lejeunea subg. Papillolejeunea (Pócs)Schust.]).Inhistreatment of Papillolejeunea,Pócs(1997:1),hementioned,“Thestrikingfeatureof the plant [Papillolejeunea] is the special development of first (distal) lobule tooth, which is papilliform, elongate, with blunt apex, consisting of two cells and standing perpendicular to the free lobe margin which is usually involuted with the blunt second (proximal) tooth.” However, the plant from Mt. Kinabaludiffered essentially by the flat free margin of the leaf lobule, which was not involuted with the second tooth. Since none of the described species of Lejeunea match our plant from Mt. Kinabalu, it is described here as a new species. The species is named in the honor of Prof. Dr. S. Robbert Gradstein, who is the expert of the Lejeuneaceae family and has encouraged our study of the genus Lejeunea in Malaysia. Description Lejeunea gradsteinii G.E. Lee, A. Damanhuri & A. Latiff sp. nov. (Figs. 1,2)Planta dioica, lobuli bidentati, amphigastria usque ad 2/3 bifida lobis obtusis.Type: Malaysia, Sabah, Mt. Kinabalu, trail from Mempening shelter to Layang-Layang staff quarters, montane forest, on tree trunk, 2500-2800 m alt., 12 November 2010, G.E. Lee 1891 (holotype, UKMB; isotype, PC). Ibid., G.E. Lee 1884, 1885, 1886, 1887, 1888, 1889, 1890 (paratypes, UKMB). Plants dioicous, 1.3–1.4 mm wide, whitish green in the field, irregularly and densely branched with branches erect-spreading to spreading. Stems ca. 0.1 mm in diameter, ventral merophyte on the stem 2 cells wide, cross-section of the stem about 6 cells high, consisting of 7 epidermis cells with thin walls surrounding 15–17 medullary cells, epidermis cells distinctly larger than the medullary cells, epidermis cells 37.5–62.5µmwide,medullarycells12.5–25.0 µm wide. Leaves approximate to imbricate, when dried plants occasionally crispate, strongly convex, not crossing the stem, when moist leaves usually plane, erect-spreading to spreading, rarely convex. Leaf lobes 0.3–0.4 mm long and 0.2–0.3 mm wide (when flattened), ovate, leaf apex obtuse, leaf margin weakly crenulate, the ventral margin almost straight with the keel, weakly arched, when flattened forming an angle of 1200–1400 with the keel, the line of insertion J-shaped, along 10–11 lobe cells with 1 celled stylus on the uppermost cell of the insertion. Leaf cells round to oblong, abruptly become smaller towards the median cells (Fig. 1: O) and gradually become smaller towards the leaf margin, basal portion of cells are more or less elongate, apical cells 20–25 µmlongand12.5–17.5µmwide,mediancells25–30µmlongand17.5–20µmwide, basal cells 25–42.5 µm long and 20–25 µm wide, cell walls hyaline,31trigones large, infrequently with intermediate thickenings. Cuticle rough, each cell covered by numerous minute papillae. Oil bodies not seen. Leaf lobulesrelatively large, never reduced, 0.3–0.4 mm long and 0.2–0.3 mm wide, up to 1/3 as long as the lobe, at an angle of about 900 to the stem, orbicular, strongly inflated along the keel, the keel curved, smooth, free margin flat (Fig. 1: N), apex obliquely truncate, with two teeth (Figs. 1: J, K, L), the first tooth conspicuous, 1–2 cells long and 2 cells wide at base, with a hyaline papilla on the proximal side, the second tooth small and indistinct, 1-celled, obtuse. Underleaves 0.2–0.4 mm long, 0.2–0.4 mm wide, 2 times as wide as the stem, distant, orbicular, covering 1/3 of the lobules, bilobed to 2/3 of underleaf length,tips narrowly rounded, lobes triangular, sinus broad, obtuse, U-shaped, margin weakly crenulate, attached to the stem by two large basal cells, base straight. Rhizoids hyaline in numerous loose fascicles, at the base of underleaves, secondary rhizoids disc lacking. Androecia terminal on short or long lateral branches, androecial shoot 0.4–0.7 (1.10) mm long, 0.3–0.4 mm wide with bracts. Male bracts in 4–13 pairs, hypostatic, lobules almost same size as the lobe, apex obtuse, free margin always flat, keels strongly inflated, arched, curved and smooth. Male bracteole 0–1, slightly smaller than the underleaf, margin crenulate, present only at the base of the androecial shoot. Antheridia 2 per bract, 70–85µmindiameter,somewhatyellowishwithashortandhyalinestalk, 40–50µminlength.Gynoecia terminal on short or long branches, bracts loosely arranged with one innovation, 1-3 gynoecia in a lateral row due to repeatedly fertile innovations, leaf sequence of innovation lejeuneoid. Female bracts smaller than the leaf, erect-spreading when moist. Lobes 0.5–0.6 mm long, 0.2–0.3 mm wide, ovate to lanceolate, apex obtuse, margin weakly crenulate. Lobules 0.3–0.4 mm long, 0.1–0.2µmwide,1/2thewidthofthelobe,3/4 the length of the lobe, almost same length as the lobe, ovate to linear, apex acute to obtuse, keels straight, smooth, 0.1–0.2 mm long. Female bracteoles 0.4–0.5 mm long, 0.2–0.3 mm wide, 1/2 as long as the perianth length, larger than the underleaf, gradually tapering toward the base, ovate with tips acute, lobes approximate, sinus narrow, acute, almost equally bifid, 1/3 bilobed, margin weakly crenulate. Cells of the female bracts and bracteoles are almost similar throughout, without intermediate thickenings, occasionally with small trigones. Perianths 0.8–1.0 mm long, 0.5–0.6 mm wide, emergent up to 1/3 of its bractlength, obovate-clavate, with 5 sharp, 0.10–0.15 mm wide keels, sometimes the keels extended above more or less as auricles, perianth with a 2–3 cells long beak, cells of the perianth at the keels mammillose, perianth base straight and without any stalk-like elongation. Sporophyte not seen. Vegetative reproduction not observed.This new species is characterized by 1) whitish green color of the plant in the field, 2) crispate and strongly convex leaves when dried, 3) weakly crenulate margin of leaves, underleaves, female bracts and bracteoles, 4) rather large, 32strongly inflated, never-reduced lobules, with conspicuously flat free margins, 5) apex of lobules with 2 teeth, 6) basal cells more or less elongate, ending abruptly towards median cells, forming a short and ill-defined vitta, 7) well-developed trigones and scarce intermediate thickenings, 8) obovate-clavate perianths with 5 sharp keels, 9) long male shoot with up to 13 pair of male bracts.Lobule characters have been accepted as a significant character in the taxonomy of Lejeuneaceae (Evans 1902, Gradstein 1994, He 1996). The large lobules with two teeth at apex (Figs. 1: J, K, L) are the most significant characteristic of this new species. This peculiar feature as well as the deeply bifid underleaves with rounded tips and the obovate-clavate perianth with sharp keels is unique among all the Malaysian Lejeunea. The leaf lobules in this species is always strongly inflated, however, the free margin appeared to be always flat throughout and visible without flattening the leaf, and the erect or suberect first tooth of the lobule is usually of 2 cells long and with 2 large cells at base (Figs. 1: J, L), the tooth pointing toward leaf apex. At times, the first tooth is only 1 cell long and with 2 large cells at base (Fig. 1: K). The second tooth is not so distinct and always blunt. On immature or weaker plants, the shoots may be only ca. 0.7–0.8 mm wide, the perianth, then, is somewhat reduced (0.6–0.8 mm long, 0.4–0.5 mm wide) and becoming obovate instead of obovate-clavate. In this situation, the perianth is only slightly emergent from its bracts (Fig. 2: g). On vigorous plant, however, the perianth is larger (0.8–1.0 mm long and 0.5–0.6 mm wide) and obovate-clavate in shape with 5 sharp keels, sometimes the keels extended above as slight auricles. The perianth is visibly emergent beyond the bracts, up to 1/3 of its length. Lejeunea gradsteinii may be confused with L. alata. In both species the leaves are usually crispate when dry, long branches are very rare and perianths are somewhat clavate with five sharp keels. However, L. gradsteinii can be easily separated from L. alata by the large lobules with two teeth at apex. Superficially, L. gradsteinii is also similar to L. pallide-virens, but the latter is autoicous and its male bracteoles are present throughout the androecial shoot.Generally, the species Lejeunea has inflated, well-developed lobule which the first tooth is usually 1-celled and the second tooth is usually reduced and invisible (He 1996). However, exceptionally there are two distinct teeth. The latter character is shared with genera such as Cheilolejeunea and Leucolejeunea(the latter genus has recently been reduced to synonymy under Cheilolejeunea; Malombe 2009, Yu et al. 2010). The first Lejeunea with two distinct teeth on the leaf lobule was described by Herzog (1930) from Yunnan, China, as L. bidentula. Subsequently, Inoue (1961) described a new species, L. kodamaefrom Japan with the same characteristic. The two species shared many features and were considered possibly conspecific (Inoue 1961). However, Mizutani (1971) revealed a number of differences between L. bidentula and L. kodamae, 33including the length of the perianth beak, the number of medullary cells of the stem in cross-section, the width of the stem with leaves, the shape of the leaf lobe, and the width of underleaf. Mizutani (1971) also reported L. bidentulafrom India and Nepal. The present new species is quite different from these two taxa as is shown in Table 1.Table 1. Morphological comparison of L. gradsteinii, L. kodamae and L. bidentula.Characters L. gradsteinii L. kodamae L. bidentulaSexuality dioicous autoicous autoicous and paroicousLeaf size (long x wide)(mm) 0.3–0.4×0.2–0.3 0.5–0.8×0.4–0.6 0.7×0.45Number of medullary cells of stem in cross-section 15–17 6–7 10–12Lobes of underleaf rounded to obtuse acute acuteFirst teeth of leaf lobules (cells long x cells wide) 1–2×1 3–4×1–2 2–3×1Androecia (bracts) 4–13 pairs 3–6 pairs 3 pairsPerianth shape obovate-clavate pyriform pyriformPerianth size (long x wide)(mm) 0.8–1.0×0.5–0.6 0.5–0.6×0.35–0.4 0.8–0.9×0.55–0.6Perianth beak (cells long) 2–3 3–4 7–8Position of perianth emergent up to 1/3 not emergent emergent up to 1/2 34Figure 1. Lejeunea gradsteinii G.E. Lee, A. Damanhuri & A. Latiff sp. nov.: A: Part of plant; B,C: Leaves; D: Apical cells of leaf lobe; E: Cross section of stem; F,G,I,M,P: Underleaves; H: Median cells of leaf lobe; J,K,L: Lobule apices; N: Leaf lobule; O: Basal cells of leaf lobe; Q: Basal cells of underleaf. (All from holotype G.E. Lee 1891).35Figure 2. Lejeunea gradsteinii G.E. Lee, A. Damanhuri & A. Latiff sp. nov.: a: Part of plant, with perianth-bearing branch; b: Apical cells of perianth; c,g: Perianths with bracts and bracteoles; d.f: Female bracts; e: Female bracteole; h,j,l: Perianths; i,k: Androecial shoot. (All from holotype G.E. Lee 1891).36ACKNOWLEGDEMENTSWe would like to thank Sabah Parks for allowing the collection of Lejeuneain Kinabalu Park and to Dr. Mizutani, curator of NICH for the loan of type specimens of L. kodamae and L. bidentula. The first author is grateful to her fiancé, Daniel Tang for accompany and assistance during the Mt. Kinabalufieldwork, toProf.Dr.TamásPócs forproviding thePapillolejeunea reprints, and to Dr. Boon Chuan for sending some of the literatures. This research is supported financially by National Science Foundation (NSF), Malaysia and Dana Operasi UKM-OUP, research fund awarded toEmer. Prof.Dato‟AbdulLatiff Mohamed. REFERENCESEvans, A. W. 1902. Hepaticae of Puerto Rico. I. Leptolejeunea. Bull. Torrey Bot. Club 29: 496–510.Gradstein, S. R. 1994. Lejeuneaceae: Ptychantheae, Brachiolejeuneae. Fl. Neotrop. 62: 1–216. New York Bot. Garden, New York.Herzog, T. 1930. Lejeuneaceae. In: Handel-Mazzetti, Symb. Sin. 5: 43–57. f. 15–21. He, X.-L. 1996. On the taxonomic significance of lobule characters in the Lejeuneaceae (Hepaticae). Ann. Bot. Fennici 33: 311–316.Inoue, H. 1961. A new Lejeunea (Hepaticae) from Japan. J. Jap. Bot. 36 (1): 7–10.Lee, G.E., A. Damanhuri, A. Latiff & S. Robbert Gradstein. 2011a. A taxonomic treatment of Lejeunea discreta, L. eifrigii and L. sordida, new to Peninsular Malaysia. Acta Biol. Pl. Agriensis (in press). Lee, G.E., S. Robbert Gradstein, A. Damanhuri & A. Latiff. 2011b. Towards a revision of the genus Lejeunea (Lejeuneaceae) in Malaysia. Gard. Bull. Singapore (in press).Malombe, I. 2009. Studies on African Cheilolejeunea (Lejeuneaceae) I: New species and new combinations. Acta Bot. Hung. 51: 315–38.Mizutani, M. 1971. Lejeunea from the Himalayan region. J. Hattori Bot. Lab.34: 445–457.Pócs,T.1997.Neworlittleknownepiphyllousliverworts.VI.Papillolejeuneagen. nov. from Papua New Guinea. Trop. Bryol. 13: 1–18.Schuster, R. M. 1998. On Lejeunea (Papillolejeunea) pocsii Schust., sp. n. of New Zealand. J. Hattori Bot. Lab. 85: 83–87.Ye, W. & Zhu, R.-L. 2010. Leucolejeunea, a new synonym of Cheilolejeunea(Lejeuneaceae), with special reference to new combinations and nomenclature. J. Bryol. 32 : 279–282.

Lejeunea gradsteinii (Lejeuneaceae), a new liverwort species from mt. Kinabalu, Sabah

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Lejeunea gradsteinii (Lejeuneaceae), a new liverwort species from mt. Kinabalu, Sabah

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