Carex relaxa V. I. Krecz.

Carex relaxa V.I.Krecz. (Fig. 3F, G) Flora of the U.S.S.R., Vol. 3: 379, 616 (Kreczetovicz 1935). TYPE MATERIAL. — Russia • Transbaikalia region, the Nercha and Kuenga Rivers, at the summit of the Sukhoi valley along the road to Nizhniye Klyuchi; 18 VI 1911; V. Sukachev & G. Poplavskaya 812; holo-, LE [LE01006982] photo! PHENOLOGY. — Flowering and fruiting from May to July. ETYMOLOGY. — The specific epithet refers to the fact that the spikelets are far apart from each other, giving the whole inflorescence a loose form. DISTRIBUTION AND HABITAT. — Carex relaxa grows in wet grasslands and is distributed in Irkutsk, Mongolia. C. relaxa was recorded in the IPNI as being distributed in China, and specifically in Qinghai province in 1998 according to GBIF, however, no specimen photographs were provided (GBIF 2024; IPNI 2024). It is hypothesized that this might actually be a case of misidentification, with the plant being C. helingeeriensis L.Q.Zhao & J.Yang. In our field studies, we found only C. helingeeriensis in the region, with no reliable specimens of C. relaxa ever being documented. In 2012, we collected C. relaxa in Stipa grandis P. A. Smirn. grasslands and S. baicalensis Roshev. grasslands of Hulunbeier City, Inner Mongolia, thereby providing substantiated evidence of its presence in China. ADDITIONAL SPECIMENS EXAMINED. — China • Inner Mongolia, Hulunbeier City, East of Xinbalhu Zuoqi, Stipa grandis P.Smirn. grassland community; 17.VI.2012; L.Q. Zhao N12-6001; HIMC[HIMC0014358]! • Ewenke Qi, Yiminhe Township, Stipa baicalensis Roshev. grassland community; 16.VII.2012; L.Q. Zhao N12-7001; HIMC[HIMC0014354]! Mongolia • Sukhbaatar, grasslands, 1600 m; 22 VII.1991; I.A. Gubanov s.n.; MW [MW0172429] (photo!). Russia • Zabaykalsky Krai, Borzinskii raion county; 18.VI.1972; V. Kuvaev s.n.; MW [MW0040266] (photo!). TAXONOMIC NOTES Carex relaxa is morphologically similar to C. helingeeriensis L.Q.Zhao & J.Yang. However, they are differentiated by their leaves, utricles, and styles. C. relaxa features involute leaves, utricles with conspicuous ribbed veins that are obovate or subglobose, nutlets that fill the utricle at maturity, and a style base that is not expanded. In contrast, C. helingeeriensis has conduplicate or spreading leaves, utricles with no veins or inconspicuous veins that are elliptic-trigonous, nutlets that do not fill the utricle at maturity, and an expanded style base (Kreczetovicz 1935; Zhao et al. 2013).