Encalypta vulgaris is well known for its wide morphological variation, here we study morphological and genetic variation of E. vulgaris in Scandinavia and compare this with the closely related E. rhaptocarpa and the morphologically similar E. mutica. Our morphological and genetic results indicate that Scandinavian plants of E. vulgaris s.l. includes two taxa, E. vulgaris s.s. and a new species here described as E. driva. The two species differ genetically by plastid markers while the included nuclear markers do not differentiate between the two. Morphologically they can be separated both by gametophytic and sporophytic characters. We also clarify the distinction between E. mutica and the newly described E. driva which have been confused in Scandinavia.
The Scandinavian bryophyte flora is still under exploration and new species are continuously discovered new for the region and described new for science (Draper and Hedenäs 2009, Høitomt et al. 2012, Hassel et al. 2014, 2018, Kyrkjeeide et al. 2015, Hedenäs 2018, 2020). The genus Encalypta Hedw. is no exception (Høitomt et al. 2016), the genus is easily recognized by the campanulate calyptra completely covering the capsule. Species are mostly easily separated, but the species boundaries in section Rhabdotheca have been pointed to as problematic (Horton 1983, Fedosov 2012). Encalypta vulgaris Hedw. belongs to section Rhabdotheca and is considered a southern species in Scandinavia reaching north to Gästrikland in Sweden and Trøndelag in central Norway (Söderström 1996, Hallingbäck et al. 2006). It is considered to be an easily recognized species in Scandinavia, only to be confused with Encalypta mutica I. Hagen from section Pytomitrium, with which it shares the obtuse leaves and lack of peristome. There are specimens named E. vulgaris from the Scandinavian mountains and northern Scandinavia, but these have by most authors been ignored and/or considered as doubtful and confused with E. mutica (Frisvoll and Blom 1997, Nyholm 1998, Hallingbäck et al. 2006).
Both E. vulgaris and E. mutica are declining in parts of their Scandinavian distribution. Encalypta mutica is considered vulnerable (VU) on the Swedish red list, due to declining populations and decreased quality of its habitat (Hallingbäck et al. 2020). It has the same red list category in Norway, the Norwegian population is evaluated to be rather stable, but with few individuals (Høitomt et al. 2021). In Finland it is evaluated as endangered (EN), only occurring close to the Swedish and Norwegian border in Enontekiön Lappi (Juutinen and Ulvinen 2017). Encalypta mutica is a rare northern species considered to be at risk of extinction in four out of the six European countries where it is recorded, and is evaluated as VU on the European red list (Hodgetts et al. 2019). Encalypta vulgaris on the other hand is evaluated as least concern (LC) in Sweden, but VU in Norway (Hallingbäck et al. 2020, Høitomt et al. 2021). The Norwegian population of E. vulgaris is declining due to change in habitat quality and loss of habitats due to various construction works, like building of roads, houses etc.
Most species of the genus Encalypta Hedw. prefer base-rich substrates that periodically dry out, and typically the leaves are lingulate with or without a hair point and have densely papillose cells. Globally, about 35 species are recognized (Frey and Stech 2009) and the highest species diversity is found in alpine regions of the northern hemisphere. In Europe, Hodgetts et al. (2020) recognized 15 species in the genus. This treatment follow the work of Fedosov (2012) on the problematic section Rhabdotheca where he suggested that Encalypta obovatifolia Nyholm and E. intermedia Jur. should be treated as synonyms of the earlier name E. pilifera Funck, and advocated that E. trachymitra Ripart should be recognized at the species level. In addition, Bryobrittonia longipes (Mitt.) D.G. Horton in Encalyptaceae is known from arctic regions of Europe. All 15 Encalypta species and B. longipes are known from Scandinavia including Svalbard.
The taxonomic problems of section Rhabdotheca Müll. Hal., treated by Fedosov (Fedosov 2012), mainly focused on taxa with morphological similarity to Encalypta rhaptocarpa Schwägr. The problematic taxonomy around E. vulgaris is still not resolved (cf. Horton 1983). In Scandinavia E. vulgaris is recognized by its obtuse epilose leaves, smooth capsules without peristome and an entire to erose base of the calyptra (Nyholm 1998, Hallingbäck et al. 2006). The latter character state separates it from species in section Pyramitrium Wallr. ex Hampe (Horton 1982), which includes E. mutica. However, when the calyptra is missing as it often is at exposed alpine localities, it is more difficult to separate the two during field work. There are reports of E. vulgaris from the Scandinavian mountains, and it has been assumed that this probably is misidentified E. mutica. Also the fringes at the base of the calyptra of E. mutica are deciduous and can be missing late in the season (Hagen 1899). However, E. mutica can be distinguished by the densely papillose costa in upper part of the leaf, which is smooth or with projecting cell ends in E. vulgaris. Another character of ‘doubtful’ specimens is that the capsules often are striate, this is a character state shared with E. rhaptocarpa s.l. and one could suspect that the plants represent a form of this taxon with muticous leaves (cf. Gallego et al. 2018) and missing peristome.
The understanding of E. mutica is further confused by the descriptions and illustrations provided by Hassel and Høitomt (2016). Afonina and Cernyadjeva (1998) and Hallingbäck et al. (2006), as their illustrations of E. mutica show a calyptra with erose base rather than a regularly fringed base (Afonina and Czernyadjeva 1998), striate capsules (Hassel and Høitomt 2016), very strong costa of the leaves (Afonina and Czernyadjeva 1998, Hallingbäck et al. 2006) and the basal cells of the leaves form a strong border (Hallingbäck et al. 2006).
Reliable identification is crucial for correct evaluation of threat status and measures of management and conservation (Bickford et al. 2007). In this paper we clarify the distinction between E. mutica and other arctic-alpine taxa with muticous leaves and missing peristome. We investigate the phylogenetic relationship of E. mutica, E. rhaptocarpa and E. vulgaris s.l., based on molecular and morphological analyses we describe E. driva sp. nova. We also provide an English translation of the original description of E. mutica by Hagen (1898) with illustrations of the type specimen.
Methods
Material
Revision of specimens in herbarium TRH, TROM, BG and O was done to confirm morphological concepts of the included taxa. To reveal genetic relationships of the included taxa, molecular analyses were performed. For molecular analyses we selected 12 specimens of Encalypta mutica (n = 2), E. vulgaris (n = 2), E. rhaptocarpa (n = 2) and E. driva (n = 6). A list of included specimens for morphological and molecular analyses are provided in Appendix 1.
Molecular analysis
Encalypta mutica belongs to the section Pyramitrium while the other taxa to the section Rhabdotheca, thus we assumed that E. mutica would act as outgroup in the phylogenetic analysis. Genomic DNA was extracted with DNeasy Plant Mini Kit (Qiagen) according to manufacture protocol. We sequenced all 12 samples with forward and reverse primers for ITS (ITS1, 5.8 and ITS2), and five chloroplast loci (rbcL, rps4, trnL–F, rpl16 and trnG, Appendix 2).
The multiple sequences alignment was performed using the Muscle (Edgar 2004) with visual inspection of the alignments. The phylogenetic analyses were conducted by using the neighbor-joining (NJ) and maximum likelihood (ML) algorithms implemented in MegaX (Kumar et al. 2018). The best fitted substitution model identified with the lowest Bayesian information criterion values for chloroplast and ITS nucleotide sequences were Tamura 3-parameter with a discrete Gamma distribution (+G) and Kimura 2-parameter with a discrete Gamma distribution (+G), respectively. Neighbor-joining analysis was performed based on p distance using the pairwise deletion of gaps. A bootstrap test with 1000 replicates was used to compute the statistical support for internal nods. The graphical representations of the trees (ML) and dendrograms (NJ) were generated with MegaX. A Neighbor-Net network was also conducted to illustrate the genetic relationships among specimens with SplitsTree4 (Huson and Bryant 2006).
Morphological analysis
To explore relative differences in morphology between E. mutica, E. vulgaris, E. driva and E. rhaptocarpa morphometric measurements of available specimens, mainly from herbarium TRH, of E. mutica (n = 49) and E. vulgaris s.l. (n = 104) were included (Appendix 1). For E. rhaptocarpa (n = 3) a selection of specimens to represent variation in ecology and distribution were included (Appendix 1). Based on the treatments of Encalypta by Horton (1983) and Fedosov (2012) morphological characters of the gametophyte and sporophyte were compared among plants (Table 1, first column lists included characters). Leaves, antheridia and archegonia as well as vaginula, capsule and spores were semi-permanently mounted in glycerol on microscope slides prior to examination. All measurements were taken using a transmission microscope and dissecting microscope, and photomicrographs were made applying a Leica Application Suite ver. 4.5.0 for stacking.
Results
Molecular results
The total aligned sequence length (bp) were 1066 and 2997 positions in the final ITS and combined chloroplast datasets, respectively (Appendix 2). All specimens were successfully sequenced for all loci except that the ITS sequence for three specimens Encalypta rhaptocarpa (B-37814), E. vulgaris (B-675760) and E. driva (B-693623), were excluded from the analyses because of low quality chromatograms. The locus rbcL showed high degree of conserved sites (99%) compared to other chloroplast and ITS regions. The percentage of parsimony informative sites varied from 1% (4 sites) in rbcL to 6% in rpl16 (49 sites) and 6% in trnG (33 sites), respectively. The ITS locus consisted of 13% (144 sites) variable sites in which most of them were singletons (10%, 108 sites). The NJ and ML analyses resulted in dendrograms with similar topologies and thus only the ML results are presented. Both nuclear and plastid loci confirm the placement of E. mutica section Pyramitrium as an outgroup (Fig. 1 and 2). The nuclear ITS locus resolved E. rhaptocarpa sister to a clade consisting of E. vulgaris and E. driva (Fig. 2). However, the combined plastid data (Fig. 1) show that E. vulgaris s.s. is sister to a clade consisting of E. driva and E. rhaptocarpa. Splits Tree analysis of the plastid data confirmed this pattern (Fig. 3).
Table 1.
Morphological characters of the studied taxa.
Morphological results
The morphological characters evaluated for E. driva, E. vulgaris, E. mutica and E. rhaptocarpa are summarized in Table 1. The characters are illustrated and compared across the taxa in Fig. 4 and 5. The original description of E. mutica by Hagen (1899) is translated (below) and the lectoptype is illustrated (Fig. 9) to avoid further confusion with E. driva.
Discussion
Morphological traits combined with molecular data supports the interpretation that Scandinavian plants of Encalypta vulgaris s.l. consist of two taxa. Encalypta vulgaris s.s. with longly oblong leaves combined with faintly striate to smooth capsules and E. driva with ovate to shortly oblong leaves and striate capsules, described below.
Figure 2.
Maximum likelihood phylogenetic tree based on ITS loci. Numbers indicate bootstrap support computed with 1000 replicates. Three specimens are excluded from the three, see text for more detail. The suffix after species name is the TRH herbarium number.
The plastid molecular markers included in this study strongly support a clade of E. driva that is differentiated from E. rhaptocarpa and E. vulgaris but the low bootstrap value to the sister clade prevents us to conclude which is the closest clade (Fig. 1). Fedosov (2012) also found poor support for some of the clades in his study of section Rhabtotheca, but he only included trnL–F as a single marker. Our nuclear markers do not differentiate between E. driva and E. vulgaris but separates E. rhaptocarpa (Fig. 2). The different outcome based on the plastid and nuclear dataset could indicate a polyploid origin of E. driva (cf. Kyrkjeeide et al. 2019), where E. driva and E. vulgaris share the paternal ancestor but have different maternal ancestors for the plastid genome. Chromosome counts of Encalypta vulgaris show either n = 13, n = 26 or n = 39 (Fritsch 1982), this could mean events of polyploidisation, and this should be investigated in future studies to understand the speciation processes in Encalypta section Rhabdotheca. Most species in the genus Encalypta are monoecious and produce sporophytes regularly, but mixed stands of E. vulgaris/E. rhaptocarpa and E. driva/E. rhaptocarpa are observed and allopolyploidisation could be an important evolutionary process as in other moss genera (Meleshko et al. 2018).
The fact that E. driva often is found growing together with E. rhaptocarpa has led to suspicion that these plants could be an epilose form of E. rhaptocarpa (cf. Gallego et al. 2018). However, both molecular and morphological results clearly suggest that it is separated from E. rhaptocarpa.
Figure 4.
Characters distinguishing the four investigated taxa. (A) Shoots with sporophytes, (B) capsule and calyptra, (C) vaginula, (D) stem leaves. Scale bars: (A) 2 mm except E. mutica 1 mm; (B) 1 mm; (C and D) 500 µm. Illustrations of E. rhaptocarpa TRH-B-37814 (Dovre, Oppland), E. vulgaris TRH-B-35516 (Trondheim), E. driva shoot, calyptra TRH-B-35956 (Lom, Oppland), capsule, leaf TRH-B-92190 (Lom, Oppland), vaginula TRH-B-772306 (Storfjord, Troms), E. mutica shoot, capsule, vaginula, leaf TRH-B-163903 (Målselv, Troms), calyptra TRH-B-38364 (Trondheim, Trøndelag).
Figure 5.
Characters distinguishing the four investigated taxa. (A) Mouth of capsule, (B) spores, distal surface, (C) dorsal side of costa near leaf apex, (D) transverse section of costa, (E) basal cells of leaves. Scale bars: (A, B, C, D) 50 µm; (E) 100 µm. Illustrations of E. rhaptocarpa TRH-B-37814 (Dovre, Oppland), E. vulgaris TRH-B-35516 (Trondheim), E. driva TRH-B-35956 (Lom, Oppland), E. mutica TRH-B-163903 (Målselv, Troms).
Figure 6.
The type of Encalypta vulgaris from Hedwig's herbarium in Geneva. Catalogue des herbiers de Genève (CHG). Conservatoire & Jardin botaniques de la Ville de Genève. 10-03-2022 (< www.ville-ge.ch/musinfo/bd/cjb/chg>).
Encalypta driva is separated from E. mutica by several characters. In the field the entire to erose base of the calyptra and the longitudinal striate capsules are key characters. In E. mutica the base of the calyptra has triangular fringes, and the capsule is usually smooth. However, as Hagen (1899) mentioned in his type description, the fringes seem to be deciduous or are worn off by harsh weather conditions (Fig. 9I). In the microscope the species are easily separated by several characters like the leaf border in the leaf base, transverse section of the costa, papillosity of the costa near leaf apex and spore size and ornamentation (Fig. 5, Table 1). The morphological separation from E. vulgaris is more problematic in the field, as both have entire to erose base of the calyptra and muticous leaves, but the type of E. vulgaris has long capsules thar are rather smooth and it is a larger plant (Fig. 6). Ecologically E. vulgaris is a lowland plant with a southern distribution in Scandinavia, while E. driva occurs both in lowland and alpine habitats. The capsule mouth cells are 15–25 µm wide in E. vulgaris s.s., compared to 12.5–17.5 µm wide in E. driva. The leaves of E. driva are in general shorter and wider than those of E. vulgaris.
Taxonomy
Encalypta driva K. Hassel & Høitomt sp. nov. (Fig. 7, 8, 9)
Holotype: TRH-B-35956, Geitåtjønne, Hestbrepiggan, Lom, Oppland. Soil-covered, calcareous cliff, 1674 m a.s.l., leg. K. Hassel 31 Aug 2017. Isotypes: MHA and S.\
Etymology
Driva is a Gygir in Norse mythology, a female Jotne, and the daughter of Snø (Snow) who is the son of Frost.
Description
Plants small to medium sized 1–5(–10) mm.
Stems irregularly branched, with scattered brown, smooth rhizoids, central strand absent to weakly differentiated, stem cortex formed by 1–3 layers of small thick-walled cells.
Leaves shortly oblong-ovate, rarely longly oblong and undulate (Fig. 8); costa strong, ending before leaf apex, serrulate by protruding cell ends in upper part; costa with ± 3 layers of sterid cells; cells subquadrate, densely papillose in the upper part, rectangular and smooth in the basal part, 2–7 rows of elongate marginal cells in leaf base, forming a border.
Autoicous with a terminal perichaetium with one to several archegonia. Perichaetial leaves ovate obtuse, outer ones larger than stem leaves, inner ones smaller and more ovate. Perigonia each consisting typically of two leaves and one or several antheridia occur in leaf axils just below the perichaetium.
Seta yellow brown to brown. Vaginula in upper part umbrella like.
Capsule cylindrical, slightly to distinctly striate to ribbed, peristome absent, capsule mouth rimmed with 2–3 rows of rounded subquadrate cells.
Spores yellow brown, with few large papillae, on the distal surface 5–6 papillae across the spore, proximal surface only slightly papillose, striate to nearly smooth; spore diameter 25–37 µm.
Calyptra yellowish, base entire to erose.
Distribution
Southeastern Norway, mainly in the lowland Oslofjord area. The southern Scandinavian Mountain range including Jotunheimen and Dovrefjell, from Trøndelag and further north it is known from both lowland and mountain areas in Nordland and eastern part of Troms. In Finnmark it is known from the Alta area and the Varanger Peninsula. A revision of E. vulagris s.l. from northern latitudes and high elevations e.g. in the Alps, will probably result in a wider distribution.
Habitat
Calcareous soil over cliffs, with some disturbance and little competition from other species.
Differentiation
Confusion is most likely towards E. mutica and E. vulgaris s.s. which both have obtuse leaves and capsules without peristome (Fig. 4). Encalypta mutica differs by papillose costa on dorsal side in upper part of leaf (Fig. 5C), only weakly differentiated border of elongated cells in basal part of leaf (Fig. 5E), narrow vaginula (Fig. 4C), capsule nearly smooth (Fig. 4B), spores with many small papillae (Fig. 5B) and calyptra with fringes at base (Fig. 4B). Encalypta vulgaris s.s. differs by its generally larger size, longer and more narrow leaves, smooth to finely striate capsules (Fig. 4B) and wider cells of the capsule mouth. One source of confusion towards E. mutica is that the vaginula of old sporophytes may have a cup-like appearance, but the vaginula is still thicker in upper part compared to E. mutica (Fig. 4C, 9).
Figure 7.
Encalypta driva. (A) shoot with sporophyte, (B) calyptra, (C) transverse section of stem, (D) two stem leaves, (E) basal leaf cells, (F) dorsal side of costa near leaf apex with projecting cells, (G) transverse section of leaves, (H) transverse section of costa, (I) leaf lamina cells in transverse section, (J) inner perichaetial leaf, (K) outer perichetal leaf, (L) perichaetium with archegonia, (M) perigonium with antheridia, (N) vaginula with seta attached, (O) capsule, (P) capsule mouth, (Q) spores from proximal and distal side. Scale bars: (A) 2 mm; (B, O) 1 mm; (D, J, K, N) 500 µm; (E, G, L, M) 200 µm; (F, C) 100 µm; (H, I, P, Q) 50 µm. All illustrations are made from the holotype TRH-B-35956.
Figure 8.
Two leaves of Encalypta driva from a plant growing sheltered from wind, the leaves are longer and more undulate than typical leaves (holotype TRH-B-35956).
Encalypta mutica I. Hagen, Tromsø Mus. Aarsh. 21: 91, 1899
Lectotype (selected by Horton 1983): TRH-B163895, Ladehammeren, Trondheim, Sør-Trøndelag, Norway. Northern exposed cliffs by the fjord, 10–20 m a.s.l., leg. I.S. Hagen 16 Aug 1895.
In the protologue by Hagen there were no illustrations, but here we illustrate the lectotype in Fig. 10.
Translated original Latin description
Tufts dense, about 8 mm high, rusty red brown inside, green on the outside. Shoot branched, fertile innovations below apex, tomentum yellow-brown scattered. Stem red-brown, 0.17 mm thick, branches in central part 0.04 mm thick, outer cells small thick walled, leptodermis cells turgid. Leaves spreading, recurved, slightly undulate or erect and more lingulate or obovate-lanceolate, up to 2.3 mm long and 0.53–0.62 mm wide, apex rounded or widely triangular or rarely in the upper part quickly tapering, always very obtuse at apex, never with hair point, plane or canaliculated, margin above basal cells roughly papillose; cells in leaf base hyaline with brown walls, rectangular 0.07–0.11 mm long and 0.013–0.016 mm wide, smooth, thin, cells at leaf margin slightly narrower forming a weakly differentiated margin; mid leaf cell regularly hexagonal, 0.011–0.014 mm long and wide, more or less incrassate, papilla bi-trifid; costa with age brownish, 0.045–0.066 mm wide, ends below apex, dorsal papillae multifid low dense, in cross section with 2–4 guide cells and dorsal stereid band, ventral dorsal surface covered with papillose cells, dorsal cells often small, slightly incrassate, always papillose.
Inflorescence autoicous rarely synoicous. Male flower (antheridia) axillar, small, thin, gemmiform; perigonia with two leaves, ovate to ovate-lanceolate, obtuse, and with costa narrow towards apex, with age brownish; antheridia about 4, 0.58 mm long and 0.14 mm wide; paraphyses few, filiform, whitish. Perichaetial leaves, two loosely arranged leaves close to the archegonia, erect-spreading, widely rounded 1.8 mm long and 0.83 mm wide, triangular narrowed in the same way as the stem leaves. Archegonia ca 4–0.56 mm long; paraphyses few to numerous, narrow, almost hyaline.
Vaginula brownish-black, oval-conical, 0.85 mm high and 0.3 mm thick, not pileated, but membrane hyaline erect, forming a pot, glossy, deciduous; Ochrea (sheath) persistent. Seta 5–8 mm long, 0.3 mm wide, brown to dark brown, twisted toward the left. Capsule cylindrical with short neck and slightly narrower opening, 2.1 mm long, 0.65 mm wide, brownish-yellow to brown, without longitudinal stria, when dry indistinctly wrinkled. Exothecial cells by the opening in two rows of sub-quadrate, minute, rectangular – rhomboid 0.08–0.11 mm long and 0.022–0.033 mm wide, thin walled. Stomata scattered in the lower part of the capsule, composed of hyaline cells, 0.044 mm long, 0.033 mm wide. Peristome absent. Annulus simple, persistent. Operculum 1.1 mm long, from the convex base forming a beak. Calyptra at the base of the capsule parallel, dirty white – yellowish, slightly shiny, base with narrow regular fringes, reddish brown later deciduous, upper half with scattered obtuse papillae, apex densely dentate rough. Spores 25–32 µm, nearly globose, brown, densely covered by moderate papilla.
Figure 10.
Encalypta mutica illustration of the lectotype TRH-B-163895. (A) Shoot with sporophyte, (B) three stem leaves, (C) basal leaf cells, (D) dorsal side of costa near leaf apex, (E) capsule, (F) capsule mouth, (G) stomata in lower half of capsule, (H) vaginula, (I) calyptras where the fringes partly have fallen of. Scale bars: (A) I 2 mm; (B, E) 500 µm; (H) 200 µm; (C) 100 µm; (D, F) 50 µm; (G) 20 µm.
Hagen (1899) reported E. mutica from four localities all in Norway; 1) Vårstigen, Oppdal, Sør-Trøndelag, leg. Kaurin 1886 (originally identified as E. vulgaris, TRH-B-163894); 2) Ladehammeren, Trondheim, Sør-Trøndelag, on chlorite schist, northern exposition, only a few m above the fjord, leg. Hagen 16.08.1895 (TRH-B-163895); 3) Nedre Bergulnesli Saltdal, Nordland, 100 m a.s.l. growing with E. rhaptocarpa, leg. Fridtz 02.08.1889; 4) north of Nedrevatnet, Vik, Skjerstad (currently Fauske municipality), Nordland, 100 m a.s.l. on soil over cliffs growing with E. rhaptocarpa leg. Hagen 17.08.1893 (TRH-B-163901).
Differentiation according to Hagen in the type description: E. mutica is closely related to E. vulgaris, but distinguished from it by the more obtuse leaves, the costa is much weaker and on the back very densely papillose, and a much smaller plant. The leaf base is consistently hyaline, while in E. vulgaris distinctly yellowish. The base of the seta has a hyaline, cup-shaped upward bent membrane. The seta is turned left, the calyptra has regular fringes at the base. The last feature is very similar to E. ciliata.
The first locality mentioned by Hagen (1899) in the protologue of E. mutica is Ladehammeren in Trondheim, Norway. This is a lowland locality by the fjord and Hagen describes the habitat as northern exposed cliffs. Encalypta mutica has been searched for at this locality, but without success (Frisvoll and Blom 1997). A lot of construction work and harbor development has taken place at Ladehammeren, and E. mutica is probably extinct at this locality. During the search for E. mutica, we have quite surprisingly, discovered populations of E. vulgaris at Ladehammeren (Hassel 2010).
Key to the species included in this study
1. Capsule and calyptra present 2
1. Sporophyte missing 5
2. Calyptra entire-erose, upper part of vaginula triangular 3
2. Calyptra fringed at base, upper part of vaginula narrow E. mutica
3. Capsule strongly striate to ribbed, with peristome (well developed or not) E. rhaptocarpa
3. Capsule smooth, striate or ribbed, peristome absent 4
4. Capsule smooth-faintly and narrowly striate, capsule mouth cells 15–25 µm E. vulgaris s.s.
4. Capsule broadly striate to ribbed, capsule mouth cells 12.5–17.5 µm E. driva
5. Leaves with hair point E. rhaptocarpa
5. Leaves obtuse without hairpoint 6
6. Costa on dorsal side with papillae in upper part E. mutica
6. Costa on dorsal side shiny without papillae, but with denticulations formed by projecting cell ends, in upper part 7
7. Plants normally 2–10 mm, leaves (1.4–)2–3 mm long, oblong, (2.3–)2.7–3.9(–4.5) times longer than wide E. vulgaris s.s.
7. Plants normally 1–5 mm, leaves 1.2–2(–3) mm long, ovate to shortly oblong, (1.5–)1.9–3.0(–3.5) times longer than wide E. driva
Acknowledgements
We thank the Norwegian Biodiversity Center for financing the Artsprosjekt ‘Moser i dårlig kjente habitat’, support to workshops on alpine bryophytes in Jotunheimen, and support to the work on Encalypta for ‘Arter pånett’. Curators of herbarium BG, O and TROM are thanked for making specimens available for study. Kjell I. Flatberg is thanked for help with translation of the original description of E. mutica.
