Sibbaldianthe semiglabra (Soják) Mosyakin & Shiyan 2017

Mosyakin, Sergei L. & Shiyan, Natalia M., 2017, The genus Sibbaldianthe (Rosaceae): a nomenclatural overview and new combinations, Phytotaxa 296 (2), pp. 101-117 : 111-112

7. Sibbaldianthe semiglabra (Soják) Mosyakin & Shiyan , comb. nov.

Basionym: Schistophyllidium bifurcum (L.) Ikonn. subsp. semiglabrum Soják (2008: 357 ; authorship cited as “Juz. ex Soják”).

Type (holotype, PR: Soják 2008: 357):— RUSSIA: [Sakha (Yakutia) Republic; In Russian— Республика Саха (ЯкутиЯ)] As cited in the protologue: “Сеntr. Jakutija, pravуj bеrеg A1 dana v 280 km vyšе ust’ja, 14. VIII. 1979, Еgorova 27 ( PR).” [In Russian: “Центр. ЯкутиЯ, правый берег Алдана в 280 км выше устьЯ. 14. VIII. 1979, Егорова 27”; translation: Central Yakutia, right bank of the Aldan River 280 km upstream from the river mouth.]

Potentilla bifurca L. β [var.] glabrata Lehmann (1851a: 33) .

Type (holotype, PR):—[probably RUSSIA]: PR 377971 (see Soják 1996: 101).

Invalid names:

≡ Potentilla semiglabra Juzepczuk (1934 [published 1935]: 124, in adnot.; Juzepczuk 1941: 83), nom. inval., descr. ross. ≡ Potentilla orientalis L. subsp. semiglabra Voroshilov (1985: 176; authorship cited as “(Juz.) Worosch.”), nom. inval. ≡ Schistophyllidium semiglabrum [Juz. ex] Soják (2004: 307), nom. inval. (nom. provis., cited as “in press”: “ Edinburgh J. Bot. 2004, in impressione”; Art. 36.1(b) of ICN); Soják (2012: 109), nom. inval. (nom. provis., cited as “Thaiszia, in press”; Art. 36.1(b) of ICN).

This species differs from S. bifurca and S. orientalis in having mainly glabrous stems in the lower third or half; upper parts of the stems and branches are mainly covered by appressed trichomes. Leaflets of this species are often narrower than those in related taxa. There are also some other morphological and anatomical diagnostic characters recently reported by Motorykina (2015), who recognized these two species in Potentilla . Moreover, both tetraploids with 2n=28 (Probatova et al. 2009; Korobkov et al. 2012; Motorykina 2015) and octoploids with 2n=56 ( Probatova & Sokolovskaya 1988; Probatova et al. 2009; Chepinoga et al. 2012) were reported for P. semiglabra . Motorykina (2015) concluded that both P. semiglabra and P. bifurca sensu stricto are represented by at least two chromosome races each, but it seems that tetraploids occur mainly (or exclusively?) in the Russian Far East and adjacent parts of China (Harbin, Heilongjiang province).

It is worth mentioning that Turchaninov (Turczaninow 1843: 614; bound volume: Turczaninow 1845: 382) already noted this distinctive taxon but reported it as an unnamed variety “β”, with the following description: “foliis linearibus elongatis, integris aut bifidis, basi decurrentibus glabris subciliatis; caulibus erectis elongatis glabris”. He further commented: “Varietatem β., quae forte diversa est species, in Dahuria observavi”. In herbarium (KW, Turchaninov Memorial Collection) he annotated the corresponding specimens from “Dahuria” with a provisional name “ P. bifurca var. longifolia mihi”. Unfortunately, this name has never been validly published by Turchaninov. However, Lehmann later validated the name P. bifurca var. glabrata Lehmann (1851a: 33) with the reference to Turchaninov’s description of his variety “β”.

Some authors synonymized P. orientalis with P. semiglabra (the same subspecies, Sibbaldianthe bifurca subsp. orientalis , according to Kurtto & Eriksson 2003; or a “southern subspecies” P. bifurca subsp. bifurca , according to Kamelin 2001). Soják (2005: 70) commented on that and noted that “ P. semiglabra is a good species with constant characters and own distribution area.”

Sibbaldianthe semiglabra occurs in the Russian Far East (Voroshilov 1985; Yakubov 1996; Probatova & Barkalov 2006; Motorykina, 2015), the eastern part of Siberia ( Kurbatskiy 1988, 2012; Ovchinnikova 2005), China ( Soják 2007; reported for “all provinces of NE China ”), and Mongolia ( Grubov 1982; Gubanov 1996). In the recent Mongolian checklist ( Urgamal et al. 2014) this species was accepted as Potentilla bifurca var. major ; this decision was most probably influenced by the treatment in the Flora of China ( Li et al. 2003).