Plagiothecium undulatum (Hedw.) Schimp.

Wolski, Grzegorz J., 2025, The genus Plagiothecium (Plagiotheciaceae) in Europe — current state of knowledge, checklist and key to taxa, PhytoKeys 253, pp. 67-102 : 67-102

Plagiothecium undulatum (Hedw.) Schimp. , Bryologia Europea 5: 195, 506, Tab. XIII. 1851.

≡ Hypnum undulatum Hedw. , Speciorum Muscorum Frondsorum 242. 1801 ≡ Stereodon undulatus (Hedw.) Mitt. , Journal of the Linnean Society, Botany 8: 39. 1865 [1864] ≡ Pancovia undulata (Hedw.) J. Kickx f. , Flore Cryptogamique des Flandres 1: 93, 1867 ≡ Neckeropsis undulata (Hedw.) Kindb. ex J. A. Allen , Mosses of the Cascade Mountains, Washington 117. 1900, hom. illeg., non (Hedw.) Reichardt ≡ Buckiella undulata (Hedw.) Ireland, Novon 11 (1): 55. 2001 . Type: Ad terram humidiusuclam sylvarum umbrosarum planitiei et montium totius Europae. Lectotype (designated by Ireland 1969): In silvis densis acerosis ad terram, in cavernosis saxosis Europae, in Hercynia, Franconia, G 00040241!

= Plagiothecium menziesii Thér. ex J. T. Wynns , in sched. Based on: New Zealand, A. Menziesi, ex hab. P. E. Boissier, cum Hypnum molluscum , ex herb. I. Thériot, PC 0132669! syn. nov.

Description.

Plants large, whitish-green; stems 3–9 cm long, more or less complanate-foliate; leaves transversely undulate, symmetrical to slightly asymmetrical, imbricate, ovate, 2.5–4.5 × 1.3–2.5 mm (Fig. 13 B ); the apex acute to obtuse, denticulate or not; laminal cells papillose, 90–175 × 7–10 μm at midleaf (Fig. 13 D ), cell areolation tight; decurrencies of 1–3 rows of rectangular to quadrate cells; setae 2.5–4.5 cm, capsule inclined.

Distribution.

Asia (Azerbaijan, China, Islamic Republic of Iran, Russian Federation, Turkey); Europe ( Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Hungary, Ireland, Italy, Latvia, Lichtenstein, Lithuania, Luxembourg, Montenegro, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom); North America ( Canada, U. S. A.).

Figures

Figure 13. Selected, most important taxonomic features of the Plagiothecium neckeroideum and Plagiothecium undulatum A, B shape and dimensions of the leaves C, D shape and dimensions of cells from the middle part of the leaves A, C P. neckeroideum (from lectotype of P. neceroideum var. mureum, Holler, C-M- 9389! and syntype of P. neceroideum var. javense, M. Fleischer, PC 0132631!, PC 0132632!) B, D P. undulatum (based of P. menziesii, A. Menziesi, PC 0132669!).