Atraphaxis ledebourii Yurtseva, 2022

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, Phytotaxa 566 (1), pp. 13-63 : 46-48

2. Atraphaxis ledebourii Yurtseva , sp. nov.

Type: — RUSSIA. Tuva: Tes-Khem Raion, the southern slope of the East Tannu-Ola ridge, dry stone bed of the Khyralyg-Khem river , 1200 m, 3 June 1972, Khanminchun 4821 (holotype MW0061283!, isotypes LE!, MHA!, NSK!) ( Fig. 21 ) .

Description: —Shrub ca 30–50 cm tall. Woody shoots up to 1 cm in diam., inclined-spreading, dark-gray, much branched, bark exfoliating and fibrously disintegrating, naking pinkish or creamy wood. Second-year shoots bear lateral branchlets 5–12 cm, 3–5 mm in diam. departing at 45 degrees, somewhat spiny after fruiting, but easily break off. Annual shoots 3–15 cm long, 0.5–1.0 mm in diam., straight, finely ribbed, glabrous, creamy, leafy, with internodes 5.0– 6.5 mm. Some annual shoots terminate with frondo-bracteose thyrses 1–2 cm long with 3–8 congested (rarely far spaced) cymes of 2–3 flowers. Leaf blades bright-green, later bluish-green or gray, rhomboid-elliptical, broadly elliptical, or obovate, 7–12(30) × 5–7(18) mm, obtuse, shortly pointed, or acuminate, suddenly narrowed to a petiole 1.0–1.0 mm, glabrous, with prominent net of veins, with smooth, flat or slightly undulate margin. Leaf ratio 2–3. Ochreas 4–7 mm long, semitransparent, silvery-whitish, cleft in two linear-lanceolate lacinulas 3–5 mm long, each with yellowish or white vein, and middle truncated lacinula finely inciso-serrated at top. Lateral lacinulas are fibrously disintegrated at margins. Ochreolas 2.5–4.0 mm, membranous, light-brown at base, transparent above, cleft in two sharp semitransparent subulate lacinulas at both sides of strongly reduced leaf blade. Perianth white, creamy, or yellowish, with filiform tube 2.0– 5.5 mm joined to a pedicel 1.5–4.0 mm long with articulation. Outer tepals rounded or elliptical, 2.0–4.0 × 2.0–4.0 mm, prominently reticulate, reflected to a pedicel. Inner tepals rotundate, 4.0–5.5(7) × 4.0–5.0 (7) mm, with slightly crenulate margin and reticulate venation. Stamens 8, filaments subulate-filiform, suddenly dilated at base. Anthers rounded-oval. Achenes 2.8–4.5 × 1.4–2.0 mm, 1.5 times shorter than inner tepals of perianth, ovoid, suddenly acuminate, trigonous, with almost flat faces, obtuse ribs, smooth, glossy, black. Styles three, 0.4–0.5(0.7) mm long, fused to 1/4–2/5, with fimbriate-capitate stigmas 0.3–0.4 mm in diam.

Etymology: —named after Ledebour who reported this taxon from Altai as Tragopyrum pungens M.Bieb.

Flowering time: —June.

Fruiting time: —July–August.

Distribution: MONGOLIA. [Uvs aimag, Zavkhan aimag]: Ubsunur depression, North Hangay; RUSSIA. Tuva: the East Tannu-Ola ridge, the Uyuk ridge along the Yenisey River; Altai Republic.

Ecology: —rocks, dry gravely and steppe slopes.

Chromosome numbers: —from 42 to 72, RUSSIA. Altai Republic: Kosh-Agach Raion, vicinity of Kokorya vill., Kostikov & Kostikova ( NSK3000910 !), and RUSSIA. Republic of Tuva: Chaa-Khol’ Raion, the shore of the SayanoShushenskii reservoir, Kostikov & Kostikova ( NSK3000907 !), both sub A. pungens (M. Bieb.) Ledeb. ( Voronkova et al. 2019) .

Figures

FIGURE 21. Holotype of Atraphaxis ledebourii sp. nov. RUSSIA.Tuva: Tes-Khem Raion, the southern slope of the East Tannu-Ola ridge, dry stone bed of the Khyralyg-Khem river, 1200 m, 03 June 1972, Khanminchun 4821 (holotype MW0061283).