Atraphaxis kuvaevii O. V. Yurtseva 2022, sp. nov.
Creators: name: Yurtseva, Olga V.
name: Vasilieva, Natalia V.
name: Kostikova, Vera A.
name: Samigullin, Tahir H.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Polygonaceae
Atraphaxis
Atraphaxis kuvaevii

description: 1. Atraphaxis kuvaevii O.V.Yurtseva, sp. nov.
Type: — RUSSIA. Krasnoyarskii Krai: West Sayan Mountains, Sayano-Shushenski Nature Reserve, left board of the Sayano-Shushenskaya water reservoir, above the Kalbakmys River, stony mountain steppe, 615 m, 3 July 1987, Kuvaev & Sonnikova 1015-13 (holotype MW0061320!, isotype NS!) (Figs 4–5, 6G–I, 7A–B).
Description (macromorphology): —Dwarf shrub 15–20(30) cm tall with tortuous extensively branched shoots. Second-year shoots 3–4 mm in diam, smooth, slightly prickly, covered with dark gray exfoliating bark hiding foxybrown wood. Annual vegetative shoots to 10–12 (15) cm long, straight, creamy, finely ribbed, glabrous, 1.0 mm in diam., leafy, with internodes 5–6 mm long. Generative shoot 1.5–5 cm long, with 3–4 leaves spaced by internodes 1–2 mm long, terminates with bracteose thyrse 10–15 mm long, with 3–4 cymes of 1–2(3) flowers. Ochreas at vegetative shoots 3–6 mm long, membranous, slightly brownish at base, above semitransparent, silvery-white at margin, split in 2 subulate lacinulas serrate-incised at margin, each with a single faintly visible vein and short middle lacinula serrateincised at margin. Ochreolas in thyrses 2,5– 3 mm long, semitransparent, cleft in two sharp teeth. Leaf blades dark green, bright green or glaucose, 8–11 × 2–6 mm at shoots, 3–4 × 1 mm in thyrses, elliptical or rhomboid-elliptical, apex rounded or shortly pointed, base cuneate, gradually or suddenly narrowed into a petiole 0.5–1.0 mm, thick, leathery, with a clear net of veins, glabrous above, finely crenulate and papillate at margin (Fig. 5A). Perianth ca. 5–6 mm long; filiform part of perianth tube 2.0–3.0 mm long, with a funnel-form extention 0.3–0.4(0.5) mm long; the tube is much longer than a pedicel 1.0 mm, or the place of articulation is hidden in ochreola (Fig. 5B–D). Outer tepals two, 2.0–2.5 × 1.5–2.0 mm, rhomboid, ovate or rotundate, reflected to a pedicel; inner tepals three, 3.0–4.0 × 2.5–2.0 mm, flat, base cuneate, apex rotundate, green at the middle, with a wide pinkish margin, slightly undulate, surround the achene, with prominent longitudinal veins or without veins. Stamens 8, filaments subulate-lanceolate, gradually dilated towards the base, anthers rounded-oval. Achene 2.0–2.8 × 1.3–1.6 mm, equal to inner tepals, trigonous, ovoid, gradually acuminate, light-brown, smooth, glossy, faces ovate- or elliptical-lanceolate, almost flat, ribes obtuse, styles three 0.3–0.4 mm long, free from the base, with papillate globular stigmas 0.2 mm (Figs 5E–F, 6G–H).
Description (pollen): —Oblong-spheroidal, 24.2–27.3 × 19.3–20.7 µm (P/E = 1.29); tricolporate, elliptical in equatorial view, rounded-trilobed in polar view; colpi are distinct, long and deep; ora distinct, lalongate or circular (Fig. 7A, B). The sporoderm ornamentation is striate-perforate with the striae 0.10–0.20 µm thick, distinct and protruding, mainly short and straight, divided by deep short grooves with 2–4 (rarely more) large perforations in a row. Exine is 2.0 (1.7–2.4) µm thick.
Etymology: —Named after Vladimir B. Kuvaev (1918—2009), a researcher of Siberian Flora who first indicated diagnostic characteristics of the taxon.
Flowering time:— June–July.
Fruiting time:— July–August.
Distribution:— RUSSIA. Southern Siberia, Krasnoyarskii Krai: West Sayan Mts, valley of the Yenisey river in Tuvinian Depression, rocky slopes of the Uyuk ridge and the West and East Tannu-Ola ridge facing the Yenisey river, Khayyrakan Mt.
Ecology:— Stony mountain steppe, nanophyton steppe, feather grass & selaginella shrubby steppe, granite or limestone rocks and slopes.
Note on the holotype: —MW0061320 was previously identified as: A. pungens (M.Bieb.) Jaub. & Spach (12 March 1988, det. Kuvaev.), A. laetevirens (Ledeb.) Jaub. & Spach (23 March 1988, det. Kuvaev), A. frutescens (L.) K.Koch (23 Mart 1988, det. Lomonosova); A. frutescens (L.) K.Koch (20 April 1988, det. Kuvaev), A. frutescens (L.) K.Koch × A. laetevirens (Ledeb.) Jaub. & Spach (6 March 2015, det. Yurtseva).
Specimens examined:— RUSSIA. Krasnoyarskii Krai: West Sayan Mts, Sayano-Shushensky Nature Reserve, left board of Sayano-Shushenskaya water reservoir, above the mouth of the creek Taldy-Chas, base of granit slope, 540 m, 3 July 1987, Kuvaev & Sonnikova 1013-6 (MW0061321!); Republic of Tuva [Ulug-Khemskii Raion]: the eastern slope of Mt Khayyrakan, on the main pass of the main saddle, on rocks. 6 July 1946, Schroeter 820 (MW0061323!); ibidem (MHA!); ibidem, 11 June 1981, Doronkin (NSK); ibidem, vicinity of Khayyrakan village, the steep bank of the Yenisey River, N51°34’27.0’’, E93°03’58.8’’, 11 July 2014, Kostikov (NSK!); ibidem, Mt Khayyrakan, stony steppe, 13 July 1974, Timokhina & Egorova 528 (NSK!); West Sayan Mts, the Uyuk ridge, environs of Bayan-Kol vill., southern slope, eastern microslope, feather grass & selaginella shrubby steppe, 7 July 1975, Lomonosova & Grushevskya 2708 (MHA!); ibidem, southern slope, eastern microslope, at rocks, 8 July 1975, Lomonosova & Iskakova 2709 (MHA!); ibidem (NSK!); 10 km E of Shagonar vill., the Shagonar rocks on the left bank of the Yenisey River, limestone rocks on the banks of the Yenisey, 650 m, 51°34’N, 93°04’E, 17 August 2002, Nikitin, Byalt & Sytin 1120 (LE!); valley of the Yenisey river, vicinity of Iiji-Tal settlment, 51°34’05.9”N, 93° 23’16.4”E, 19 July 2006, Shmakov et al. K3-2360 (ALTB!); [Biy-Khem kozhuun at the border with the Krasnoyarskii Krai], the right board of the Sayano-Shushenskaya hydropower reservoir, the Sayan canyon at the mouth of the Chamge (Chinge) river, flat surface of the ancient upper terrace of the Yenisey river, nanophyton steppe with Atraphaxis and Spirea hypericifolium dominated, at the upper sides of deep ravines, 540–600 m, N51°42’39.9’’, E092°17’46.5’’, 17 July 2014, Sonnikova (MW!); [Kyzyl kozhuun] right bank of the Yenisey river 40 km West of Kyzyl, at the rock “Dzharga”, in a ravine on the southern gravelly slope, 27 July 1947, Schroeter 281 (MHA!).
description: Published as part of Yurtseva, Olga V., Vasilieva, Natalia V., Kostikova, Vera A. & Samigullin, Tahir H., 2022, A broadly sampled 3 - loci plastid phylogeny of Atraphaxis (Polygoneae, Polygonoideae, Polygonaceae) reveals new taxa: III. A. kuvaevii and сryptic species in A. pungens from Southern Siberia and Northern Mongolia, pp. 13-63 in Phytotaxa 566 (1) on pages 45-46, DOI: 10.11646/phytotaxa.566.1.2, http://zenodo.org/record/7103418