## 2 Results
### Taxonomic Description  
_Lejunea malaysiana_ [PERSON] and [PERSON], _sp. nov._ (Figures 2-4). Type: Peninsula Malaysia, Pahang, Genting Highlands, along the forest trail to the Goh Tong Jaya station near the waterfall, at 845 m elevation, 6 May 2011, _[PERSON] and [PERSON] 11001_ (holotype: UMMP 01730; isotype: UKMB). Diagnosis: Affinity to the tropical Asian _L. cocoes_ Mitt. in the ovate leaves with narrowly rounded apices, smooth cuticles, laminal cells with indistinct trigones and without intermediate thickenings, and distantly arranged underleaves with divergent lobes but differs by its caducous leaves, strongly reduced leaf lobules, long-keeled obovoid perianths and autoicy. Figure 1: Bayesian Inference (BI) phylogeny of _Lejeunea_ based on three markers from nuclear and plastid DNA. Bayesian Posterior Probability (BPP) \(\geq\) 0.95 is indicated by a star; maximum likelihood probabilities \(\geq\) 70 are shown at branches. Accessions of \(L\). _malaysiana_ (initially assigned to \(L\). _cocos_), highlighted in yellow, are grouped together with high support (BS 100, BPP 1) whereas accessions of \(L\). _cocos_ (without caducous leaves), highlighted in red, formed another independent lineage. Species with caducous leaves are in red font. Figure 2: _Lejeunea malaysiana_ [PERSON], _sp. nov._ (**A**) Part of plant. (**B–E**) Leaves. (**F**,**G**) Caducous leaves. (**H–K**) Underleaves. (**L**) Leaf lobule. (**M**) Apical cells of leaf lobe. (**N**) Basal cells of leaf lobe. (**O**) Cross-section of the stem. (**P**) Leaf lobule (reduced). (**Q**,**R**) Cells of underleaves. All were drawn from the holotype, _[PERSON] and [PERSON] 11001_ (UMTP). Figure 3: _Lejeunea malaysiana_ [PERSON] and [PERSON], _sp. nov._ (**A**) Part of plant, with the perianth-bearing branch. (**B**) Perianth with bracts and braceole. (**C**) Apical cells of the perianth. (**D**) Perianth. (**E**) Cells at the lateral keel of the perianth. (**F**) Female braceole. (**G**,**H**) Female bracts. (**I**) Androeical shoot. All were drawn from the holotype, _[PERSON] and [PERSON] 11001_ (UMTP). Figure 4: Vegetative reproduction of _Lejeunea malaysiana_ [PERSON] and [PERSON], _sp. nov._ (**A**) Ribbon-like regenerant. (**B**) Young plantlet on top of the ribbon-like regenerant. (**C**) Mature plantlet, fall off from the caducous leaf. (**D**,**E**) Ribbon-like and young plantlets on marginal cells of caducous leaves. All were drawn from the holotype, _[PERSON] and [PERSON] 11001_ (UMTP). Plant autoicous, 0.6-0.7 mm wide, irregularly branched. _Stem_ ca. 50 \(\upmu\)m diameter, about 4-5 cells high in cross-section, epidermal cells 7, 20-38 \(\upmu\)m wide, medullary cells 4-5, 15-25 \(\upmu\)m wide. _Leaf lobes_ distant to contiguous, 0.30-0.45 \(\times\) 0.20-0.35 mm, ovate to ovate-oblong; leaf apex narrowly rounded, always flat; leaf margin weakly crenulate due to projecting cells; the ventral margin forming an angle of 150\({}^{\circ}\)-170\({}^{\circ}\) with the keel when flattened; insertion line about 8-10 lobe cells. _Leaf cells_ quadratic to hexagon; apical cells 18-25 \(\times\) 13-20 \(\upmu\)m, median cells 25-30 \(\times\) 20-25 \(\upmu\)m, basal cells 25-38 \(\times\) 20-25 \(\upmu\)m; cell walls hyaline with small or indistinct trigones and without intermediate thickenings; cuticle smooth; oil bodies not seen. _Leaf lobes_ strongly reduced, ca. 0.1 \(\times\) 0.07-0.1 mm, ovate, keel curved, free margin incurred partially; the hyaline papilla on the proximal side of the first tooth; the cell below the first tooth is of the same size as the first tooth, undifferentiated, 20-25 \(\times\) 14-20 \(\upmu\)m. _Underleaves_ 0.12-0.15 \(\times\) 0.10-0.15 mm, to 2-3 times wider than the stem, distant, ovate to orbicular (as long as wide), covering 1/4 of the leaf lobules; bilobel, lobes to 2/3-3/4 of underleaf length, about four cells wide; sinus broad, acute to obtuse, U to widely V-shaped; underleaf margin slightly crenulate; the two large basal underleaf cells differentiated; base straight.