Ranunculus tojibaevii Schegol. & Turginov, 2022

Shchegoleva, Natalia V., Nikitina, Elena V., Juramurodov, Inom J., Zverev, Andrei A., Turginov, Orzimat T., Jabborov, Anvarbek M., Yusupov, Ziyoviddin, Dekhkonov, Davron B., Deng, Tao & Sun, Hang, 2022, A new species of Ranunculus (Ranunculaceae) from Western Pamir-Alay, Uzbekistan, PhytoKeys 193, pp. 125-139 : 125

publication ID	https://dx.doi.org/10.3897/phytokeys.193.70757
persistent identifier	https://treatment.plazi.org/id/200BBEC3-EDDC-5391-B0F9-79F409C8D487
treatment provided by	PhytoKeys by Pensoft
scientific name	Ranunculus tojibaevii Schegol. & Turginov
status	sp. nov.

Treatment

Ranunculus tojibaevii Schegol. & Turginov sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3

Diagnosis.

Similar to R. botschantzevii , R. convexiusculus and R. alpigenus morphologically, but differing in the rounded-reniform radical leaves dissected into 3-5 segments, each 2-5-partite into elongated lobes rounded at the apex (Fig. 4 View Figure 4 ). Ranunculus tojibaevii differs from R. alpigenus in having fewer levels of leaf blade dissection. It differs from R. convexiusculus in the dissection of the radical leaf blades, larger flowers and having somewhat white, bristle-like hairs on the root collar and also from R. botschantzevii by the rounded apical lobes of the basal leaves and more xeromorphic habit.

Type.

Uzbekistan. Hissar Ridge , Baysuntau , Khodzha-Gurgur-ata Mountains, vicinity of the Village Gumatag, 38°22.2888'N, 67°21.0834'E, 2482 m a.s.l., 30 May 2019, N. Shchegoleva, A. Jabborov, O. Turginov (holotype: TASH-003743; isotypes: TASH-003748, TASH-003749, TASH-003750, TK-002339) GoogleMaps .

Description.

Herbs perennial. Roots dimorphic, some roots subulate, up to 0.5 mm thick, storage roots palmately-thickened, ca. 2.5 mm thick; root collar with milk-white bristle-like hairs. Stems 10-12(-15) cm tall, up to 2 mm diam., erect, branched, pubescent with white curly hairs, 1-3-flowered. Leaves dimorphic, radical leaves 2-3, 1.6-2 × 1.5-2.2 cm, blade rounded-reniform, 3-5-dissected, segments 2-5-partite, elongate, lobes apically rounded; cauline leaves 1-2, petiole short, slender, blade trisected, lobes 0.6-0.9 × 0.1-0.2 cm, oblong-lanceolate. Flowers 1.6-2.4 cm diam., sepals 0.4-0.6 mm long, ovate-concave, sparsely white pubescent; petals 0.9-1.2 cm long, well-developed, ovate, apex rounded. Infructescence globose-ovoid; receptacle oblongoid, glabrous; achenes 1-1.8 mm long, with white bristle-like hairs; beak hamate-curved.

Specimen seen (paratype).

Uzbekistan. Pamir-Alay, South-western spurs of the Hissar Ridge, Baysuntau, vicinity of the Village Gumatag, amongst the stones, 4 June 2013, O. Turginov (TASH-003754).

Phenology.

Flowering in May. Fruiting in May and June.

Distribution.

Ranunculus tojibaevii is distributed in the Khodzha-Gurgur-ata of the Baysuntau Mountains area of Hissar Ridge (Fig. 5 View Figure 5 ). The closely-related R. convexiusculus is endemic to Central Asia and R. botschantzevii is endemic to the Western Pamir-Alay.

Habitat and plant associations.

Ranunculus tojibaevii is rupicolous on southern and western exposed limestone outcrops and in cracks and crevices of large boulders at 2,450-2,500 m. a.s.l. The region is alpine and rather xerophytic. The common taxonomic composition of phytocenosеs includes Cerasus amygdaliflora Nevski ( Rosaceae ), Corydalis ledebouriana Kar. & Kir. ( Papaveraceae ), Cousinia regelii C.Winkl. ( Asteraceae ), Eremurus regelii Vved. ( Asphodelaceae ), Gagea gymnopoda Vved. ( Liliaceae ), Iris khassanovii Tojibaev & Turginov, I. parvula (Vved.) T.Hall & Seisums, I. stolonifera Maxim. (all Iridaceae ), Rheum maximowiczii Losinsk. ( Polygonaceae ), Tulipa lanata Regel ( Liliaceae ) and Ziziphora pamiroalaica Juz. ( Lamiaceae ).

Conservation status.

Ranunculus tojibaevii is a local, narrowly distributed endemic, represented by two or three individuals per m2 within an area of <500 m2. It should therefore be assigned the status EN (Endangered), Criteria B1 ab(i, ii, iii)+ B2 ab(i, ii, iii), following the IUCN Standards and Petitions Committee ( IUCN 2019).

Notes.

Ranunculus tojibaevii differs from closely-related species by its habitat on well-heated limestone outcrops, as well as in cracks and crevices of large boulders at ca. 2,500 m a.s.l., which is atypical of related species. Ranunculus convexiusculus is on clayey-stony soil, less often on slopes of fine earth, at 2,000-2,600 m a.s.l. Ranunculus botschantzevii is hygrophilous in wet mountain meadows with melting snow and on slopes of fine clayey soil at 2,400-3,500 m a.s.l. Ranunculus alpigenus grows on slopes of fine soil of the alpine belt at 2,800-4,000 m a.s.l. All these species are endemic to the western Pamir-Alay. The vicariant species to R. alpigenus is R. badachschanicus Ovcz. & Koch. from the western Pamirs.

Etymology.

Ranunculus tojibaevii is named after Komiljon Tojibaev, a leading botanist, professor and academician from Uzbekistan who actively promotes the botanical sciences in Central Asia.