2. Taxonomy and Botany

Within the Lamiaceae family, Lagochilus  belongs to the subfamily Lamioideae and tribe Leonureae Dumort^[12] [12]. Species of Lagochilus are subshrubs or perennial herbs (Figure 1). Rootstocks are woody. Stems are green-white, rigid, and sparsely hirsute. The leaf blade is rhombic, palmatipartite, or pinnatipartite, with lobes spinescent, sometimes subtending sterile spinescent bracteoles. Normally, 2–10 flowers grow vertically. The calyx is campanulate to tubular-campanulate, 5-veined; throat oblique, straight; teeth five, subequal or three posterior teeth longer, triangular to oblong or broadly ovate, usually longer than the tube, apex spinescent. Corolla is villous outside, pilose annulate inside, 2-lipped; upper lip oblong, straight, slightly concave, 2-lobed or 4-toothed; lower lip obliquely spreading, 3-lobed; middle lobe largest, obcordate, 2-lobulate; lateral lobes straight, acute, or emarginate. Stamens are four, exserted or sub included, anterior two longer; with filaments complanate; anther cells two, parallel or divergent, ciliate. Style is filiform, apex subequally 2-cleft. Nutlets are flattened-obconical, oblong–obovoid or oblong–ovoid, apex truncate or rounded, glandular, dusty hairy, scaly, or glabrous, smooth.

Figure 1. Photograph for some Lagochilus species from Uzbekistan Flora (A): L. inebrians Bunge, (B): L. nevskii Knorring, (C): L. occultiflorus Rupr., (D): L. olgae Kamelin, (E): L. platycalyx Schrenk, (F): L. proskorjakovii Ikramov, (G): L. seravschanicus Knorring, (H): L. setulosus Vved., (I): L. vvedenskyi R. Kam. (Photos A, B, D, G are taken by Natalya Beshko, photos C, H are taken by Alim Gaziev, photo E is taken by Tulkin Tillaev, photos F, I are taken by Akbar Akhmedov).

3. Diversity

The genus Lagochilus  is mostly distributed on dry slopes, in valleys, and deserts from Iran to Mongolia, Russia (south Siberia), northwest China, north Pakistan^[1] [1] and has a distributional center in Tianshan Mountains and Central Asia. The results of the studies of Zhang et al. [3] showed that the Tianshan Mountains, especially the western Ili-Kirghizia Tianshan, as well as Sunggar and Kaschgar, were the ancestral area. The ancestral biome was mainly in the montane steppe zone of valley and slope at altitudes of 1700 ± 2700 m above sea level, and the montane desert zone of foothill and front-hill at 800 ± 1700 m. The main center of diversity lies in Central Asia. According to Tskervanik^[12] [12], in world flora, there are 44 species that can be distinguished in Lagochilus. According to the taxonomy of this author, 34 species grow in the territory of the CIS (Commonwealth of Independent States).

In the flora of Uzbekistan, this genus is represented by 18 species (Table 1)^[13] [13]. Taxa of the genus Lagochilus  basically occur throughout the territory of Uzbekistan, starting from the deserts to Tian-Shan and Pamir-Alay mountain systems. The majority of species can be found in the Pamir-Alai Mountain, south-west of Tian-Shan and Turanian lowland^[13] [13]. Species from the genus Lagochilus belong to the most vulnerable plant species from the Lamiaceae family. Out of the existing 18 Lagochilus  species in the flora of Uzbekistan, four are included in the Red Book of the Republic of Uzbekistan^[14] [14]: L. vvedenskyi, L. olgae, L. proskorjakovii, and L. inebrians. The main population of these species grows in Nuratau and Kyzylkum deserts. On the basis of occurrence, these Red List plant species belong to category I (disappearing) and II (rare species). In addition, the natural distribution of other species from this genus, such as L. gypsaceus and L. acutilobus,  are also limited across the country^[15] [15]. In the territory of South Kazakhstan, 10 species of Lagochilus  were found, and the areas of these species are located in Karatau, Karzhantau, and Aksu-Zhabagly^[16] [16]. In the Flora of China, there are 14 Lagochilus species distributed wildly in the northwest region. One of the species, L. ilicifolius, grows in the desert (sandy land) and steppe in northwestern China (Neimeng, Gansu, Shanxi, and Ningxia provinces), whereas the other 13 species are distributed mainly in the Xinjiang region^[3][10][17] [3,10,17]. The Flora of Iran comprises six species, and four of them (L. macranthus Fisch and C.A. Mey., L. quadridentatus Jamzad, L. lasiocalyx (Stapf) Jamzad, and L. aucheri  Boiss.) are endemic to Iran^[4][18][19] [4,18,19]. Three species of Lagochilus are found in Mongolian flora, and they are widely distributed in the Khangai, Mongolian Altai, Middle Khalkha, Depression of Great Lakes, Valley of Lakes, East Gobi, Gobi-Altai, Transaltai Gobi, Alashan Gobi regions (Table 1)^[20][21] [20,21].