Oncophorus wahlenbergii Brid., 1826

Lars Hedenäs, 2017, Scandinavian Oncophorus (Bryopsida, Oncophoraceae): species, cryptic species, and intraspecific variation, European Journal of Taxonomy 315, pp. 1-34 : 20-23

2. Oncophorus wahlenbergii Brid.

Figs 7 , 8

Bryologia Universa 1: 400 (von Bridel 1826). – Dicranum wahlenbergii (Brid.) Schultz, Sylloge Plantarum Novarum 2: 149 ( Schultz 1828). – Dicranum virens var. wahlenbergii (Brid.) Huebener ,

Muscologia Germanica: 231 ( Hübener 1833). – Aongstroemia wahlenbergii (Brid.) Müll.Hal. , Synopsis muscorum frondosorum omnium hucusque cognitorum 2: 610 ( Müller 1851). – Cynodontium wahlenbergii (Brid.) Hartm., Handbok i Skandinaviens Flora, Ed. 10, 2: 113 ( Hartman 1871). – Type: no potential type material is extant in B (cf., Frahm et al. 1998; Hedenäs 2005), and the typification will be dealt with separately (Hedenäs & Ochyra, in prep.).

Dicranum homannii Boeck in Hartman, Handbok i Skandinaviens Flora, Ed. 2: 314. ( Hartman 1832). – Type: [Norway] “Dicr. Homanni, Sp. nov. e Gudbrandsdal, dedit Boeck, lectum 1830 Jun. l. Jul., Ahnfeldt” in Herbarium Claës Gustaf Myrin, in Herb. Hj. Möller (iso-: S-B231701!).

Oncophorus virens var. gracilis Broth., Acta Societatis pro Fauna et Flora Fennica 6 (4): 75 ( Brotherus & Saelan 1890). – Oncophorus wahlenbergii var. gracilis (Broth.) Arnell & C.E.O.Jensen, Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar 21 Afd. 3 (10): 52 ( Arnell & Jensen 1896). –

Cynodontium virens var. gracile (Broth.) Paris , Index Bryologicus Supplementum Primum 111 ( Paris 1900). – Cynodontium wahlenbergii var. gracile (Broth.) Mönk., Die Laubmoose Europas : 195 ( Mönkemeyer 1927). – Type: [Russia] “V. F. Brotherus M. F. E. 434. Oncophorus virens (Sw.) Brid. var. gracilis Broth., Lapponia murmanica, in ripa arenosa fluvii Varsina, Aug. 11, 1887, leg. V. F. B.” (iso-: S-B234603!).

Oncophorus sardous Herzog (syn. nov.), Allgemeine Botanische Zeitschrift für Systematik, Floristik, Pflanzengeographie 16: 84 ( Herzog 1910). – Type: [Italy] “Fl. v. Sardinien, Auf Baumstumpf im Steineichenwald under d. Tonneri, 1100 m., leg. Th. Herzog, 4.1904, Typus!”, S; reg. no. B107132 (holo-: JE, n.v.; iso-: S-B107132!, H, n.v.).

Oncophorus gracillimus Dixon, Records of the Botanical Survey of India 9 (5): 304. pl. 1: f. 1 ( Dixon 1926). – Type: [India] “On wood, Kamri Pass & Kishenganga Valley, India, 8,000 14,000 ft. alt., J. Garrett & W. Lillie, Aug. 1924, Comm. D. Lillie (Herb. H. N. Dixon Ref. No. 1138)” (holo-: BM, n.v. – synonymized by Frahm et al. 1998).

Description

Plants from a few mm to several cm high, in loose tufts or dense cushions, green or yellow-green. Stem with large central strand, a cortex plus epidermis of 1–2 layers of incrassate cells, epidermis not differentiated as a hyalodermis; axillary hairs with (1–)2–4-celled, hyaline upper portion, 7–12 µm wide, basal 1–2 cells rectangular, hyaline or pale brown; rhizoids strongly branched, red-brown, smooth, in leaf axils or shortly above. Leaves 1.4–4.4 × 0.3–0.8 mm, when moist from sheathing base erect to spreading and straight or slightly curved, when dry with middle leaf spreading and gradually curved upwards-inwards and slightly curled or weakly curled, from oblong or slightly oblong-obovate sheathing portion (narrowed towards insertion) with narrowly triangular to almost linear upper portion, gradually narrowing upper portion, apex obtuse, acute, acuminate or narrowly acuminate; leaf margin plane throughout, below entire, above entire or with one or few occasional and indistinct, mostly obtuse teeth, especially close to leaf apex, sometimes with cell walls distinctly projecting along upper margin, margin varying from unistratose to bistratose; costa 31–88 µm wide near base, with dorsal and ventral epidermis cells slightly widened but incrassate, one layer of large guide cells, 1–2 layers of ventral stereids and 1–3 layers of dorsal stereids, sometimes with projecting cell walls or cell portions in upper costa; lamina cells in acumen incrassate, 10–33 × 10–15 µm, 0.9–2.4 times as long as wide, in mid-leaf incrassate, 10–33 × 8–17 µm, 0.9–3.0 times as long as wide, and in sheathing lamina strongly incrassate and eporose or indistinctly porose, 30–72 × 7–15 µm, 3.4–8.3 times as long as wide, transition between mid-leaf and basal cells gradual, due to relatively long mid-leaf cells and relatively short basal cells, lamina of basal, sheathing portion of leaf with quadrate or rectangular cells extending down along margin from spreading lamina; alar cells undifferentiated or a few cells wider than other basal cells, unistratose, not or shortly and narrowly decurrent. Perigonia lateral on stem, not or shortly stalked, antheridia protected by oblong-triangular perigonial leaves with obtuse or acute apex. Inner perichaetial leaves 2.73–4.24 mm long, lower 34–67% oblong and broadly sheathing, above suddenly narrowed to long, narrow acumen. Seta tall, 9–22 mm; capsule obloid, curved or slightly curved, with distinct struma, 0.5–1.3 × 0.3–0.7 mm, 1.2–2.5 times as long as broad, more or less orthogonal; exothecial cells incrassate, sometimes more strongly so in longitudinal walls, not or weakly collenchymatous; stomata sparse, ovate-pored or lacking pore, surrounded by radially arranged cells, near base of capsule; peristome red, teeth cleft or perforated to one-fourth or further down, with longitudinal rows of pits on outside; spores 21–29(–32) µm, finely rough.

Remarks

Oncophorus wahlenbergii is the smallest Scandinavian species. Contrary to O. elongatus it has quadrate or rectangular marginal cells in the middle and basal portions of the basal, sheathing lamina. In addition, its vegetative leaves are shorter than in O. elongatus , and in their upper potions the margins are entire or have occasionally one or a few indistinct teeth, especially close to the leaf apex. In some plants the cell walls project distinctly along the upper margin, and sometimes on the uppermost back of the costa.

Habitat and distribution in Scandinavia

Oncophorus wahlenbergii is most often found in open wetlands, but occurs also on soil, rocks, wet rocks, and on shores ( Fig. 4 ). The species is widespread, but compared with O. elongatus it is much less common outside the mountain range and the far north ( Fig. 3B ), and has only been collected a few times in the southern third of Sweden.

Nomenclatural notes

The isotype of Oncophorus sardous Herzog (Herzog 1910) in S has plane leaf margins and no or few marginal teeth near the leaf apex, and several rows of short cells along the leaf margin in the sheathing lamina. Despite an earlier synonymisation with O. virens Hedw. ( Frahm et al. 1998) , the material unambiguously belongs to O. wahlenbergii Brid. The partly mammillose apical costa back and few marginal teeth or projecting cell walls remind about the molecularly identified O. wahlenbergii B ( Fig. 1 ). However, since the geographical origin of the O. sardous type is distant from Scandinavia, further information is required to confidently judge its relationship with other O. wahlenbergii specimens.

The protologue of Oncophorus gracillimus Dixon (Dixon 1926) mentions entire or almost entire leaf margins, which indicates that the synonymy with O. wahlenbergii suggested by Frahm et al. (1998) is correct.

Figures

Fig. 1. NeighborNet split network for the 104 specimens studied, based on ITS (A) and the chloroplast markers trn G and rps 4 (B): Oncophorus crispifolius (O. c., 2 specimens), O. dendrophilus (O. d., 2), O. elongatus (24), O. rauei (O. r., 2), O. virens (22), O. wahlenbergii (22), O. integerrimus Hedenäs sp. nov. (26), and outgroup (light grey boxes: C. s. = Cynodontium strumiferum, 2; R. f. = Rhabdoweisia fugax, 2). Haplotype networks based on all samples of O. elongatus, O. virens, O. wahlenbergii, and O. integerrimus Hedenäs sp. nov. are shown distal to ‘ branches’ identified in the split network to show the full resolution among haplotypes. Circle size in the haplotype networks is proportional to the number of sampled populations of a certain haplotype, and sample numbers are explained in Table 1. Circles connected by a line differ in a single mutational difference; black dots indicate ‘ missing’ haplotypes. Jacknife support values of 75 – 94.99 and 95 – 100 are indicated by transverse grey and black lines, respectively.

Fig. 3. Geographical distributions in Scandinavia. A. Oncophorus elongatus (n = 459). B. O. wahlenbergii (n = 333). C. O. virens (n = 361). D. O. integerrimus Hedenäs sp. nov. (n = 247). The distribution maps are based on the S material for which geographical origin could be determined.

Fig. 4. Habitat preferences of Oncophorus elongatus, O. wahlenbergii, O. virens, and O. integerrimus Hedenäs sp. nov. in Scandinavia, based on label information from studied material in S.

Fig. 7. Oncophorus wahlenbergii A (specimen P 225; cf., Table 1). A. Stem leaves. B. Upper leaf acumen. C. Portion of leaf at widest point, showing the flat margin. D, E. Sheathing leaf portions, showing short marginal leaf cells (margin to the right) and, in D, alar region.

Fig. 8. Oncophorus wahlenbergii B (specimen P 234; cf., Table 1). A. Stem leaves. B. Upper leaf acumen. C. Uppermost leaf acumen at higher magnification. D. Sheathing leaf portion, showing short marginal leaf cells and alar region (margin to the left).