Atraphaxis kuvaevii, Yurtseva & Vasilieva & Kostikova & Samigullin, 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 : 21-22

Atraphaxis kuvaevii sp. nov.

Atraphaxis kuvaevii , a local endemic of Tuva, forms a separate subclade in both plastid and ITS trees and does not show introgression with other species ( Figs 1 and 3 ). It is a dwarf schrub 10–25 cm in height, with divaricately branched second-year shoots and annual generative and vegetative shoots 2–5 cm long ( Fig. 4 , Table 1 ). Leaves are small, rhomboid ( Fig. 5A ). Generative shoots terminate with thyrses with 3–5 cymes of 1–2 flowers. The perianth is small, with a tube articulated to a pedicel in ochreola ( Fig. 5B, C ). The epidermal cells covering the perianth tube and the tepals do not differ from those of A. pungens and A. ledebourii ( Fig. 6A–F ). Fruits are smooth and glossy, light brown, with three styles terminated with globular stigmas ( Fig. 5D–F , Fig. 6G–I ).

Atraphaxis kuvaevii has tricolporate pollen grains 27.4–27.7 × 14.5–15.9 µm with striate-perforate sporoderm ornamentation: it has short grooves and 2–3 perforations in a row ( Fig. 7A–B ), while the pollen surface of A. pungens ( Fig. 7C ) and A. decipiens ( Fig. 7D–E ) has distinct striae and long grooves with 5–6 perforations in a row.

Atraphaxis kuvaevii clearly differs from other species of Atraphaxis with the smallest leaf blades, perianth, and the tepals cuneate at the base, the filiform perianth tube articulated to the pedicel in ochreolae, and the smallest fruits ( Table 1 ). Atraphaxis kuvaevii was previously mistaken for A. laetevirens distributed in Kazakhstan, Altai and Dzhungaria. Both species have small glands at the edges and on the lower surface of leaf blades, and light-brown glossy fruits, but the fruits of A. kuvaevii are equal to the inner tepals, while the fruits of A. laetevirens are 2–3 times smaller than the inner tepals of the perianth. Atraphaxis laetevirens falls different subclades in both plastid and ITS trees. Thus, the morphological and molecular data support A. kuvaevii as a distinct species distributed in Tuva and the South of Krasnoyarskii Krai ( Fig. 8 ).

RUSSIA. Krasnoyarskii Krai: the West Sayan , Sayano-Shushensky Nature Reserve , left board of the Sayano-Shushenskii water reservoir, above the Kalbakmys river, stony mountain steppe, 615 m, 3 July 1987, Kuvaev & Sonnikova 1015-13 (holotype MW0061320 )

Figures

FIGURE 1. Maximum likelihood tree of Atraphaxis inferred from the combined chloroplast data set (trnL(UAA) intron + trnL-trnF IGS and rpl32-trnL(UAG) IGS) of Atraphaxis with Bactria ovczinnikovii as outgroup. Numbers above or below branches indicate aBayes support values (aB) equal or more than 0.7 and the posterior probabilities from Bayesian analysis (PP), equal or more than 0.9, respectively. The names of subclades are in the text.

FIGURE 3. Maximum likelihood tree of Atraphaxis inferred from nuclear ribosomal DNA ITS1–2 regions, aligned according to the prerRNA secondary structure of the ITS1 and ITS2 loci. Numbers above or below indicate aBayes support values (aB) equal or more than 0.7 and the posterior probabilities from Bayesian analysis (PP), equal or more than 0.9, respectively. The names of ribotypes see in the text.

FIGURE 4. Holotype of Atraphaxis kuvaevii Yurtseva sp. nov.:

FIGURE 5. Atraphaxis kuvaevii Yurtseva sp. nov.: leaf blades (A), perianth (B, C), styles (D, E), and fruit (F). A, E–F—(154) RUSSIA. Krasnoyarskii Krai: the West Sayan, Sayano-Shushensky Nature Reserve, left board of the Sayano-Shushenskii water reservoir, above the Kalbakmys river, stony mountain steppe, 615 m, 3 July 1987, Kuvaev & Sonnikova 1015-13 (MW0061320— holotypus). B–D—(155) RUSSIA. Krasnoyarskii Krai, the West Sayan, Sayano-Shushensky Nature Reserve, Taldy-Chaz stream, 3 July 1987. Kuvaev & Sonnikova 1013-6 (MW0061321). Scale bar = 1 mm (A–C); = 0.5 mm (D–F).

FIGURE 6. Epidermal cells of perianth tube (A, C, E), tepals of perianth (B, D, F), fruits (G, L), styles (H, J, K), and fruit surface (I). A, B—A. kuvaevii (154), RUSSIA. Krasnoyarskii Krai: Kuvaev & Sonnikova 1015-13 (MW0061320, holotype). C, D—A. pungens (255), RUSSIA. Khakassia:Askiz Raion, Kazanovka, Skvortsov (MW0061302). E, F, K—A. ledebourii (59), MONGOLIA. Ubsunur: S of Altan-Els, 70 km NE of Baruun-Turuun, 5 July 1988, Kamelin et al. 867 (LE). G–I—A. kuvaevii, RUSSIA, Tuva: Ulug-Khem Raion, West Sayan Mts, vill. Bayan-Kol, 8 July 1974, Lomonosova & Iskakova 2709 (MHA, NS). J—A. pungens (192), RUSSIA. Tuva: West Sayan, Kartushibinskii ridge, Semiozersk Slaughterhouse, 13 June 1980, Shaulo & Danilov 3867 (MHA). L—A. decipiens × A. ledebourii (238), RUSSIA. Tuva: Ulug-Khem Raion, West Sayan Mts, the Uyuk ridge, vill. Bayan-Kol, 6 August 1976, Lomonosova & Ivanova 2408 (MHA). Scale Bar = 10 µm (A-F); = 300 µm (G), =100 µm (H); = 30 µm (I); =500 µm (J); =3 µm (K, L).

FIGURE 7. Pollen of A. kuvaevii (A, B), A. pungens (C), A. decipiens (D, E), A. decipiens × A. ledebourii (F). A, B—tricolporate pollen grain of A. kuvaevii, RUSSIA. Tuva: Ulug-Khem Raion, West Sayan Mts, the Uyuk ridge, vill. Bayan-Kol, 8 July 1974, Lomonosova & Iskakova 2709 (MHA, NS). C—tricolporate pollen grain of A. pungens (255), RUSSIA. Khakassia:Askiz Raion, the river Askiz, Kazanovka, 23 June 2001, Skvortsov (MW0061302). D, E—loxocolporate, syncolporate pollen grains and pollen with ring-like form of ectoapertures of A. decipiens, KAZAKHSTAN. Aktiubinsk reg.: Temir Raion, 1950, Proskuriakova (MHA). F—tricolporate pollen grain of A. decipines × A. ledebourii (238), RUSSIA. Tuva: Bayan-Kol vill., Lomonosova & Ivanova 2408 (MHA). Scale Bar = 3 µm (A, B); = 10 µm (C, E), =30 µm (D); = 5 µm (F).

FIGURE 8. Distributional map of Atraphaxis species in RUSSIA: Tuva, based on plastid haplotypes: 1—A. pungens. 2—A. ledebourii. 3—A. × uyukensis. 4—A. decipiens. 5—A. decipiens × A. pungens. 6—A. kuvaevii. 7—A. decipiens × A. ledebourii.