Oncophorus

Lars Hedenäs, 2017, Scandinavian Oncophorus (Bryopsida, Oncophoraceae): species, cryptic species, and intraspecific variation, European Journal of Taxonomy 315, pp. 1-34 : 17

Key to Scandinavian Oncophorus species

1. Stem leaf margin plane throughout; alar cells not or weakly differentiated from other basal cells...2

– Stem leaf margin at least partly distinctly recurved in lower leaf; alar cells well differentiated......3

2. Lamina of basal, sheathing leaf portion in its middle and lower portions with long and narrow cells along margin; margin and often back of costa in upper (10–)25–35(–50)% of many leaves denticulate or dentate, often sharply so, rarely with only a few leaves having scattered obtuse teeth above. Vegetative leaves 2.5–6.4 × 0.4–1.2 mm..........................1. O. elongatus (I.Hagen) Hedenäs

– Lamina of basal, sheathing leaf portion with quadrate to elongate-rectangular cells extending down along margin (from spreading lamina); margin and back of costa smooth, with an occasional and mostly obtuse and irregular denticle (mostly close to leaf apex), or sometimes with projecting cell walls. Vegetative leaves 1.4–4.4 × 0.3–0.8 mm...........................................2. O. wahlenbergii Brid.

3. Leaf margin in acumen and often down to mid-leaf regularly to irregularly dentate or coarsely denticulate with mostly sharp and often some double teeth, strong teeth often directed forwards, occasional leaves less distinctly dentate. Dry leaves with acumen from above sheathing base erect and tightly incurved to spreading, above strongly twisted........................3. O. virens (Hedw.) Brid.

– Leaf margin in acumen entire or indistinctly and obtusely denticulate, occasionally distinctly denticulate close to leaf apex. Dry leaves with acumen from above sheathing base erect-patent to spreading and loosely incurved or curved upwards, upper acumen loosely but relatively strongly twisted.........................................................................................4. O. integerrimus Hedenäs sp. nov.