Table 1 Somatic karyotypes of studied taxa

Casearia velutina Bl.^a

Menghai County, Yunnan Province, China, Sep. 2020, 1675 m, [CAF Zhang Zhongshuai 20200926-1]

2n = 44

Dianyuea turbinata (H.J. Dong & H. Peng) C. Shang, S. Liao & Z.X. Zhang^b

Yingjiang County, Yunnan Province, China, July 2020, 1412 m, [CAF Zhang Zhongshuai 20200701-1]

2n = 38

Bennettiodendron leprosipes (Clos) Merr.^b

Malipo County, Yunnan Province, China, June 2021, 1200 m, [CAF Xiao Bo 20210620-1]

2n = 42

Idesia polycarpa Maxim.^b

Baoxing, Sichuan Province, China, July 2020, 1364 m, [CAF Zhang Zhongshuai 20200718-12]

2n = 42

Baoxing, Sichuan Province, China, July 2020, 1364 m, [CAF Zhang Zhongshuai 20200718-13]

2n = 42

Wenxian, Gansu Province, China, July 2020, 765 m, [CAF Zhang Zhongshuai 20200725-4]

2n = 42

Carrierea calycina Franch.^b

Baoxing County, Sichuan Province, China, July 2020, 1364 m, [CAF Zhang Zhongshuai 20200718-14]

2n = 40

Poliothyrsis sinensis Oliv.^b

Shennongjia County, Hubei Province, China, May 2021, 1204 m, [CAF Zhang Zhongshuai 20210504-1]

2n = 40

Itoa orientalis Hemsl.^b

Jingxi City, Guangxi Province, China, August 2020, 800 m, [CAF Jiang Rihong 20200828-1]

2n = 40

Populus adenopoda Maxim.

Wenxian County, Gansu Province, China, July 2020, 765 m, [CAF Zhang Zhongshuai 20200725-1]

2n = 38

Populus cathayana Rehder

Meixian County, Shannxi Province, China, July 2020, 2182 m, [CAF Zhang Zhongshuai 20200725-1]

2n = 38

Populus ciliata Wall. ex Royle

Luozha County, Xizang Province, China, June 2020, 2844 m, [CAF Zhang Zhongshuai 20200619-22]

2n = 38

Populus davidiana Dode

Wenxian, Gansu Province, China, July 2020, 715 m, [CAF Zhang Zhongshuai 20200725-13]

2n = 38

Populus glauca Haines^a

Dingjie County, Xizang Province, China, June 2020, 2867 m, [CAF Zhu Xinxin 20200615-1]

2n = 38

Populus pamirica Kom.^a

Aketao County, Xinjiang Province, China, May 2021, 2737 m, [CAF Zhang Zhongshuai 20210518-10]

2n = 38

Populus szechuanica Schneid.^a

Wenchuan County, Sichuan Province, China, July 2020, 2223 m, [CAF Zhang Zhongshuai 20200717-47]

2n = 38

Populus wilsonii Schneid.^a

Meixian, Shannxi Province, China, August 2020, 2491 m, [CAF Zhang Zhongshuai 20200801-1]

2n = 38

Populus yatungensis (Z. Wang & P.Y. Fu) C. Wang & S.L. Tung^a

Yadong County, Xizang Province, China, June 2020, 3430 m, [CAF Zhang Zhongshuai 20200616-3]

2n = 38

Populus yunnanensis Dode^a

Tengchong Shi, Yunnan Province, China, April 2021, 2385 m, [CAF Zhang Zhongshuai 20210417-10]

2n = 38