Pylaisia brotheri Besch., Ann. Sci. Nat. Bot.

Ignatova, E. A., Kuznetsova, O. I., Shafigullina, N. R., Fedosov, V. E. & Ignatov, M. S., 2020, The genus Pylaisia (Pylaisiaceae, Bryophyta) in Russia, Arctoa 29 (1), pp. 135-178 : 168-169

8. Pylaisia brotheri Besch., Ann. Sci. Nat. Bot. ser.

7, 17: 369. 1893.

Figs. 25 : 1–15; 26.

Note on taxonomy. Previous authors considered this species only moderately rare in the southern part of the Russian Far East (Bardunov & Cherdantseva, 1982), relying probably on the leaf shape and broader group of alar cells. As already discussed above, molecular phylogenetic analysis does not support a separate status of such morphotypes. Instead, a separate position was found for only one sample, which in addition to the mentioned leaf characters has also long perichaetial leaves clasping the seta base, a character used as one of diagnostic by Arikawa (2004). Therefore our circumscription of this species is based on this morphotype, which seems to be very rare among available collections (some collections previously referred to P. brotheri are transferred to P. condensata ). The opinion of Bardunov & Cherdantseva (1982) is likely biased by their extensive field observations in the southernmost part of the Russian Far East, Khasan District, near the border with North Korea, there P. brotheri seems to be more common in rather open and more dry forest dominated by Quercus dentata .

Arikawa mentioned the spore size of P. brotheri being 20–30 µm as a distinctive character from P. condensata (as P. selwynii ) where they are 16–25 µm. However, Noguchi (1994) reported for P. condensata (as P. selwynii ) also rather large spores, 20–30 µm, which agree with Russian specimens of P. condensata .

The type material of P. brotheri in BM has in general more broad, subglobose capsules, although in the sequenced collection of P. brotheri from Russia capsules are not so broad ( Fig. 25 ). Some capsules in the type are also similar in shape to those from Russian collection.

Description. Plants small to medium-sized. Stems and branches straight to curved, loosely to densely foliate; leaves homomallous, turned outwards substrate. Stem leaves from ovate-triangular base gradually tapered to narrowly lanceolate acumina, 0.8–1.2× 0.3–0.5 mm; margins subentire; median laminal cells 40–55×4–5 µm, alar cells subquadrate and transversely rectangular, in a rather large, more or less triangular group, 20–25 cells long and ca. 10 cells wide. Branch leaves markedly smaller, lanceolate. Inner perichaetial leaves erect, to 2.1 mm long. Capsules ovoid or broadly so. Peristome in dry state forms a low conus due to adherence of its elements. Exostome teeth to 200 µm long, dorsal plates smooth below, papillose above; endostome adherent to exostome teeth to about teeth halves; segments narrow, split except their uppermost part; endostome moderately papillose. Spores 20–30 µm.

Distribution. Pylaisia brotheri occurs in Japan and SE China ( Arikawa, 2004); in the Russian Far East it is apparently a rare species in Primorsky Territory.

Specimens examined: RUSSIA: Primorsky Territory, Vityaz Bay , 13 Oct 1978, L.V. Bardunov (ex IRK, MHA9047211) .

Figures

Fig. 25. Pylaisia brotheri (1–15, B, OK2799, Russia, Primorsky Territory,Ussurijsky Reserve) and P. condensata (16–24, CoB2, OK2796, Rus- sia, Primorsky Territory, Chandolaz Mt.). 1–2, 16: capsules; 3–4: habit, dry; 5–8, 18–20: stem leaves; 9, 24: basal laminal cells; 10, 23: me- dian laminal cells; 11: upper laminal cells; 12– 14, 21–22: branch leaves; 15–16: perichaetial leaves. Scale bars: 5 mm for 4; 2 mm for 1–3, 17; 1 mm for 5–8, 12–16, 18–22; 100 µm for 9– 11, 23–24.