Dicranum afoninae Tubanova, 2024

Dicranum afoninae Tubanova View in CoL sp. nov. Figs. 2–4 View Fig View Fig View Figure 4 .

Type : RUSSIA, Southern Siberia , Trans-Baikal Territory , Kalar District. Yuzhno-Muysky Range, Koyra Creek (56°13’59.5” N, 115°52’ 59.5” E, alt. 589-600 m). Rocks covered by mosses near creek, on rotten wood, 07.VIII.2012, coll. O.M. Afonina #8312. Isolate 378 [Holotype UUH! Isotype LE!] GoogleMaps .

Diagnosis. The species is similar to Dicranum flagellare and D. mayrii in having cylindrical, straight capsules, flagelliform branchlets and short cells of upper part of leaves, but differs from them in having leaflets of flagelliform branchlets with the acute, slightly recurved apices and slightly serrulate margins; shorter, mostly transverse-rectangular distal lamina cells; and peristome teeth with smooth outer surface.

Etymology. The new species is named in honor of the collector of the type specimen, famous Russian bryologist, Dr. Olga M. Afonina.

Description. Plants in dense, compact tufts, light to bright green, not glossy. Stems 1–2 cm, branched, moderately to densely tomentose. Leaves lanceolate, gradually narrowed towards apex, acuminate, canaliculate or keeled distally, straight or slightly curved when wet, (1.5–) 2–3(–4)× 0.4–0.6 mm, crisped and curled when dry; margins plane, entire or slightly serrulate distally, unistratose; costa 60–100 µm wide, occupying 1/5–1/7 of leaf width at base, slightly scabrous above on abaxial surface, percurrent, with one row of guide cells, two stereid bands, adaxial epidermal layer of cells not differentiat- ed, abaxial layer differentiated or irregular; lamina unistratose, in upper part, smooth or slightly scabrous on abaxial surface; distal lamina cells subquadrate, short rectangular or transverse rectangular, (2.5–)8–14 (–20)×(7.5–)10–15(–17) µm, with thin walls, not porose; proximal lamina cells short to elongate rectangular, (14–) 24–46(–79)×(8–)10–14(–21) µm, with moderately thickened walls, porose, abruptly becoming short in mid-leaf; alar cells light brownish, unistratose, not reaching costa. Asexual reproduction by flagelliform branchlets up to 5 mm long, arising in upper leaf axils; leaflets of flagelliform branchlets small, 0.2–0.5 mm long, ovate-lanceolate, acute, with slightly serrulate margins and slightly recurved apices, breaking off in fragments. Dioicous. Inner perichaetial leaves convolute-sheathing, with strong costa, abruptly narrowed into subulate acumina. Setae 6–10 mm, yellowish. Capsules erect, straight, cylindric, urns 1.5–2 mm long, pale to light brown, slightly ribbed when dry. Annulus 2(–3)-layered, falling off in fragments. Peristome single, consisting of 16 teeth split distally into 2 prongs, with longitudinal perforations in proximal part, orange to red proximally and colorless or reddish distally, ca. 360 µm long; outer surface smooth below and in the middle and weakly papillose in distal part; inner surface with low trabeculae. Operculum conic, with a long, straight beak, 1.5 mm. Spores 15–20 µm, slightly papillose.

Differentiation. There are several species in the genus Dicranum with flagelliform branchlets occurring in Russia: D. afoninae , D. flagellare , D. mayrii , D. montanum Hedw. , and D. ignatovii Tubanova & Fedosov. Their morphological differences are summarized in Table 1. The specific feature of D. afoninae is the smooth outer surface of peristome teeth. This character is also observed in D. laevidens , which, however, lacks flagelliform branchlets and is contrastingly different in other morphological features. All other Dicranum species, including flagellate ones, have peristome teeth longitudinally striolate proximally and papillose distally on abaxial surface.

The flagelliform branchlets are similar in Dicranum afoninae , D. flagellare and D. mayrii , particularly in the last two species. In D. afoninae , leaflets of the flagelliform branchlets are apiculate, slightly serrulate at margins, with slightly recurved apices, whereas in D. flagellare and D. mayrii they are obtuse, incurved, with entire margins and straight apices. Dicranum montanum differs from all other flagellate species by having leaflets of flagelliform branchlets narrow, serrate, crisped when dry and commonly deciduous, often leaving the branches partially denudated. Leaflets of flagelliform branchlets of Dicranum ignatovii are similar to those of D. montanum in shape, but they are longer, 0.5–1 mm, breaking off with branch pieces (0.3–0.5 mm long, deciduous in D. montanum ) ( Fig. 4 View Figure 4 ).

Dicranum ignatovii differs from all species mentioned above in having bistratose alar groups; stem leaves widely keeled in distal and broadly acute; costa ending before apex. In the molecular phylogenetic tree, it is resolved far from them but within the D. acutifolium -group.

Distribution and habitats. Dicranum afoninae occurs in Russia (Irkutsk Region, Republic of Buryatia, Trans-Baikal Territory, Amur Region, Jewish Autonomous Region, Khabarovsk Territory, Primorye Territory) and in Mongolia (Khovsgol, Selenge, Tov and Bulgan). It grows on rock outcrops, stones, rotten wood, and on the bases a tree trunks. The list of examined specimens is given.

Additional specimens examined:

RUSSIA. Irkutsk Region: Slyudyanka District, foothill of Khamar-Daban Ridge , 30.VIII.2018, Tubanova S 180124 ( UUH) . Republic of Buryatia: (1) Dzhida District, Maly Hamar-Daban Ridge , 31.VIII.2020, Tubanova M 202211 ( UUH) ; Baikal Nature Reserve, Abidui River , 27.VII.1991, Kazanovsky ID 1719 ( IRK, UUH); (2) Yeravna District , vicinity of “Ozerny GOK”, 04.VIII.2008, Tubanova ErT-23/0812 ( UUH); (3) Zaigraevo District, Kurbinsky Ridge , 25.VII.2017, Tubanova An-170211 ( UUH); (4) Zakamensk District, Dzhidinsky Ridge , 28.VI.2018, Tubanova Z 182504 ( UUH); (5) Kurumkan District, Dzherginsky Nature Reserve , 09.VII.1999, Tubanova 43( III) ( UUH); (6) Kyakhta District, the vicinity of Naushki Village , 18.VII.2010, Tubanova Kyah-5/10-4 ( UUH); (7) Pribaikalsky District, coast of Baikal Lake , 28.VI.2014, Tubanova B 14012/42, B14012/43 ( UUH); (8) Tunka District, vicinity of Turan Village , 16.VI.2022, Tubanova T 220202 ( UUH) . Trans-Baikal Territory: (1) Sokhondinsky Biosphere Reserve, Agutsa River , 12.VII.2013, Chernyadeva 26-13 ( LE, UUH); (2) Alkhana National Park , 21.VII.2005, Afonina 3405 ( LE, UUH) . Amur Region: Zeysky Reserve, Tukuringra Ridge , 03.VIII.1980, Stetsura 3(758) ( IRK, UUH) . Jewish Autonomous Region: Obluchye District, Maly Khingan Ridge , 16.VI.2018, Tubanova E 183007 ( UUH) . Khabarovsk Territory: (1) Verkhnebureinsky District, Bureya Riv- er 27.VIII.1997, Ignatov 97-723 ( MHA, UUH); (2) Sovetsko- Gavansky District, Botchinsky Nature Reserve , 19. VIII.2013, Ignatov, Ignatova 13-876 ( MHA, UUH) . Primorskiy Territory: (1) Dalnegorsk District, 5 km to the NW from the Krasnorechenskiy Village , 30.VIII.2013, Ignatov, Ignatova, 13-1588 ( MHA9100587 About MHA ); (2) Ol’khovaya Mt. , 04.X.2006, Cherdantseva s.n. ( VBGI, UUH); (3) Lazo District, the road to Benevsky Waterfalls , 10.IX.2014, Fedosov 14-2-002 ( MW, UUH); (4) Vladivostok, the pass to Lazurnaya Bay , 28.IX.1974, Bardunov, Cherdantseva, s.n. ( IRK); (5) Verkhne-Ussuriysky Statzionar , 20.VII.1980, Cherdantseva, s.n. ( IRK); (6) Kavalerovo District ,

Morphological features D. afoninae D. mayrii

Leaves when dry Strongly crisped Strongly crisped

Leaf sizes, mm (1.5–)2–3(–4) (2.5–)4–5 ×0.4–0.6 ×0.7–0.9

Leaves distally Tubular to slightly Tubular to slightly keeled keeled

Costa width, µm 60–100 100–150

Costa width relative 1/7–1/5 1/5–1/3

Costa length percurrent to shortly percurrent to

to leaf width excurrent shortly excurrent

Costa adaxial absent proximally epidermis differentiated to

fragmentary

Leaf cells in distal partSubquadrate to Subquadrate to transverse-rectangular transverse-rectangular

Leaf cells in distal (2.5–)8–14(–20)× (5.5–)8.5–15(–20) part, µm (7.5–)10–15(–17) ×(5.5–)8–12.5(–13)

D. flagellare D. montanum D. ignatovii

Falcate-secund Strongly crisped Slightly curved to flexuose-straight to flexuose

(2–)3–4 (1.5–)2.5–3.5(–4) 2.5–4.1(–4.9) ×0.4–0.6 × 0.2–0.4 ×0.6–0.8

Tubular Tubular to slightly Widely keeled with keeled recurved margins

70–120 40–80 80–130

1/4–1/6 1/5–1/4 1/5–1/8

percurrent to percurrent to shortly ending below apex shortly excurrent excurrent to percurrent

absent absent absent

Quadrate to Subquadrate to Subquadrate to short rectangular transverse-rectangular transverse-

rectangular

(4.5–)8– 20(–41) (4–)8.5–14(–25) (6–)9–13(–18) ×(5–)8–12(–16) ×(6.8–)9.5–13(–17.8) ×(6–)11–15(–19)

Proximal leaf cells, (14–)24–46(–79) (26.5–)38.5–67(–86.6) (16.5–)27–54(–84) (11.3–)20–42(–72) (17–)35–61(–88.5) µm ×(8–)10–14(–21) ×(9–)11–15(–17) ×(5–)9–13(–17.8) ×(4.8–)8–12(–15.5 ×(6–)9–12(–14.7)

Flagelliform Branched and Branched and branchlets fragile fragile

Leaflets of flagelliform Apiculate, Obtuse, with branchlets crenulate, with incurved apex

recurved apex

Capsule lengths, mm 1.5–2 1.5–2.5

Capsule color pale to light dark brown, glossy

Capsule surface smooth to slightly smooth

when dry wrinkled

Seta length, cm 0.6–1.0 1.2–2.0

Seta color yellowish to brownish

Annulus, cell rows 2(–3) 2–3

Branched and Branched, with Branched and fragile caducous leaves fragile

Obtuse, with Narrow, serrate, Broadly acute, incurved apex crisped slightly serrate,

straight

2–2.5 1.5–2.5 1.7–2

pale to brown brown pale brown

ribbed furrowed smooth to

slightly wrinkled

1.5–2.5 0.7–1.5 0.6–0.9

yellowish yellowish to reddish yellowish

1–2 1–2 1–2(–3)

Peristome smooth and weakly longitudinally striolate longitudinally longitudinally striolate weakly longitu-

outer surface papillose distally and papillose distally striolate and and papillose distally dionally striolate papillose distally to almost smooth below and middle, obliquely striolate and weakly papillose distally

Spores, µm 15–20 13–22 13–22 10–18 14–19

Habitats Rocks, rotten wood, Rotten wood, Rotten wood, Rotten wood, Tree trunks, tree bases tree bases tree bases tree trunks, tree bases rotten wood

Vysokogorsk , 10.IX.1977, Bardunov et al. s.n. ( IRK); (7) Partizansky District , Lazovsky Reserve, 22.IX.1974, Bardunov et al. s.n. ( IRK); (8) Terney District , Isakov Klyuch, 03.IX.2013, Ignatov et al. 13-1813 ( MHA 9-100589 About MHA ); (9) Chuguev District , Bulyga-Fadeeva, 24.IX.1976, Bardunov s.n. ( IRK); (10) Khasansky District , “Kedrovaya Pad” Nature Reserve, 1958, Ardeeva s.n. ( LE, UUH); (11) Khankajskiy District , Sinyaya Mt., 02.IV.2011, Malashkina Pr-01-11-11 ( VBGI, UUH); (12) Shkotovsky District , vicinity of Lukyanovka Village, 20.IX.2015, Tumurova VL-3-3 ( UUH); (13) Ussuriysky Nature Reserve , 23.VII.1974, Nesterova s.n. ( IRK) .

MONGOLIA. Khovsgol County, Source of Sharga River , 18.VII.2012, Enkhjargal 2982 ( UBA) . Selenge County, Darkhan-Ull , 17.VII.2005, Tsegmed et al. 14048, 14045 ( UBA) . Tov County, Southern slope of Bogdo-Ula Mountain , 26.VII.1995, Tsegmed 11 893 ( UBA) . Bulgan County: Buteligt Nuruu Ridge , 05.VIII.1995, Tsedendash 12103 ( UBA) .

Full label data are available at the supplementary materials, SM: (https://kmkjournals.com/upload/PDF/ Arctoa /33/ Arctoa _33_ Dicranum _SM.docx).