Lepidium lacerum

German, Dmitry A., 2014, Taxonomic remarks on some Asian Lepidium s. l. (Brassicaceae), Phytotaxa 186 (2), pp. 97-105 : 98-99

1. Lepidium lacerum s. l.

Lepidium lacerum subsp. rubtzovii (Vassilcz.) D.A. German , comb. et stat. nov. ≡ Lepidium rubtzovii Vassilczenko (1966: 40) . Type:— KAZAKHSTAN. [Almaty prov.] Region of middle reaches of Kegen’ . East margin of Chol’-Adyr Mts. , saline tertiary clays. 1 VII 1946. N.I. Rubtzov s.n. (holotype AA!; isotype LE!).

Lepidium rubtzovii Vass. was described based on the single gathering from saline habitats in SE Kazakhstan ( Vassilczenko 1966) and till now it was known only from the type collection. Due to a late phenological stage (mature fruits, in holotype with nearly all valves fallen down), some important features (i. e., shape of lower leaves) could not be characterized properly. Based on morphology of the remaining leaves (narrowly linear and entire) it was suggested to be related to L. coronopifolium Sprengel (1815: 72) and especially to its eastern, entire-leaved race known as L. songaricum Schrenk in Fischer & Meyer (1841: 98) ( Vassilczenko 1966). It was mentioned in the protologue that the new species differs from L. coronopifolium s. l., in particular, in the fruit characters (shorter styles and more profoundly reticulate valve surfaces). Indeed, with its broadly ovate and symmetric silicles, L. rubtzovii is distinct from L. coronopifolium having broadly elliptic to round fruits some of which are usually oblique but reminds L. lacerum . Another collection from nearly locus classicus of L. rubtzovii (Valley of Sarydzhaz, saline steppe near Kegen’, 30 V 1932, S.Yu. Lipschitz 90) recently found in MW under the name L. eremophilum Schrenk in Fischer & Meyer (1844: 199) provided better opportunity to characterize morphology of basal leaves of the taxon in focus. While smaller ones are as narrow and entire as on the type, some better evolved leaves are sublyrate, incised to divided, with 1–2(3) pairs of triangular to linear-lanceolate lateral teeth or lobes identical to those of L. lacerum . Hence, the set of both generative and vegetative characters unambiguously indicate very close affinity of L. rubtzovii to L. lacerum . At the same time, some differences among specimens from Kegen’ and typical plants of L. lacerum from Dzhungaria (Central East Kazakhstan) have been revealed (see the key below). The most obvious of them is much more developed pubescence of L. rubtzovii . Although indumentum is rather unreliable character in Lepidium which should be used with caution, in combination with geographical distinction and a slight but stable difference in fruit morphology and plant size it can justify treating the discussed taxa as two subspecies to be separated as follows.

1. Pedicels glabrous. Silicles without apical notch. Plants 20–50(60) cm tall. Central East Kazakhstan, West Mongolia ( East Kazakh upland, Dzhungaria, Dzhungarian Gobi, Mongolian Altai) ..................................................................... L. lacerum subsp. lacerum

- Pedicels crisped pilose adaxially. Silicles apically slightly notched. Plants 10–20(30) cm tall. SE Kazakhstan, NW China (foothills of North and East Tian Shan: valleys of Kegen’, Sarydzhaz; vicinities of Urumqi, Qitai, Yi Wu, Hami)........................................... .................................................................................................................................................................. L. lacerum subsp. rubtzovii

Lepidium lacerum was rather recently recorded from China based on two gatherings, Yunatov & Yuan 42a (LE) and Xinjiang Team 268 (PE), from Urumqi and its vicinities ( Zhou et al. 2001). A study of those and additional collections showed that it is much wider distributed in the northern foothills of East Tian Shan and that all Chinese specimens morphologically fit subsp. rubtzovii . A finding of subsp. lacerum in Chinese Dzhungaria is rather probable but at the moment a presence of only subsp. rubtzovii in China is confirmed.

Additional Chinese specimens examined:— CHINA. Xinjiang. Between Qitai county and Gan He Zi, 700 m, desert, 24 September 1957, Guan Kejian [K.C. Kuan] 5130 (PE 01055941!, sub nom. L. ferganense Korsh. ; duplicate in XJBI!, sub nom.? L. lacerum C.A. Mey. ); Urumqi county, Yan Er Wo, 14 May 1978, Guan Kejan [K.C. Kuan] 18036 (PE 01055942!, sub nom. L. ferganense ); 20 km west of Qitai, dry sedimentary slopes, 250 m, 24 September 1957, [Soviet-Chinese Xinjiang Expedition] 2290 (LE!); Qitai county, Ji Ji lake, 900 m, 11 June 1964, Z.X. An 380 (XJA!, sub nom. L. apetalum Willdenow 1800: 439 ); Near Urumqi, Ula Bai, 1100 m, 27 July 1964, Anonymous 48754 (XJA!, sub nom. L. ferganense ); [East of Urumqi], Mu Lei county, 20 September 1983, Anonymous s.n. (XJA!, sub nom. L. ferganense ); Yi Wu, 2010 & 2140 m, 19 July 1983, Li Xian Wen 275 (XJA!, sub nom. L. apetalum Willd. ); Near Urumqi, Yaomo Shan, 29 June 1979, Man Ying Lan 29027 & 29040 (XJA!); Near Urumqi, 820 m, May 1957, Anonymous 19881 (XJA!); Qitai county, desert, 700 m, 24 September 1957, Guan Kejian [K.C. Kuan] 5131 (XJBI!, sub nom. L. apetalum ); Qitai county, desert, 760 m, 17 August 1963, Liu Guojan 8614 (XJBI!, sub nom. L. apetalum ); Qitai county, desert, 1020 m, 8 June 1984, Feng Huilan 00775 (XJBI!, sub nom. L. apetalum ); Urumqi county, desert, 5 May 1984, Feng Huilan 00424 (XJBI!, sub nom. L. apetalum ); Urumqi county, desert, 920 m, 17 May 1962, Anonymous 186 (XJBI!, sub nom. L. ferganense ); Urumqi county, Wu La Bo, dry hill slope, 17 May 1962, Anonymous 03488 (XJBI!, sub nom. L. apetalum ); Hami county, 790 m, May 1964, Anonymous s.n. (XJU 00006324B!, sub nom. L. ferganense ).

Lepidium lacerum is also reported for more southern and western regions such as NW Tian Shan and Pamir Alai ( Vinogradova 1974, Nikitin & Geldikhanov 1988). In my opinion, in having strongly carinate, round-ovate to roundelliptic, often oblique silicles with sessile to subsessile (vs. born on a style 0.2–0.6 mm long) stigma, lanceolate-elliptic to elliptic (vs. lanceolate to narrowly lanceolate) replum, and height to 100 cm alt., such plants are distinct from L. lacerum (incl. subsp. rubtzovii ) and much closer to L. ferganense . Thus, occurrence of L. lacerum in Uzbekistan and Turkmenistan cannot be confirmed; relevant specimens are commented below.