Research Article |
Corresponding author: Xin-Fen Gao ( xfgao@cib.ac.cn ) Academic editor: Hugo de Boer
© 2020 Meng Li, Steven P. Sylvester, Zhang-Pei Wang, Yi-Da Pei, Xin-Fen Gao, Yuan Zhao, Wen-Qi Jiang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Li M, Sylvester SP, Wang Z-P, Pei Y-D, Gao X-F, Zhao Y, Jiang W-Q (2020) Re-instatement of Sorbus harrowiana (Rosaceae), based on morphometric analysis. PhytoKeys 166: 29-39. https://doi.org/10.3897/phytokeys.166.57672
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Sorbus harrowiana (≡Pyrus harrowiana), previously considered a synonym of Sorbus insignis (≡Pyrus insignis) in the Flora of China, is re-instated here and shown to be distinct from S. insignis, based on morphometric analysis, coupled with herbarium and field investigation. We also present for the first-time full descriptions, distributional records and notes for S. harrowiana and S. insignis.
George Forrest, herbarium research, morphometric analysis, Pyrus, taxonomy
Sorbus L. sensu lato (Rosaceae) contains approximately 260 species that widely occur in the temperate zone of the Northern Hemisphere (
Many species within Sorbus are difficult to delimit, including S. insignis (Hook. f.) Hedl. (≡Pyrus insignis Hook. f.), which bears similarities with S. harrowiana (Balf. f. & W. W. Smith) Rehd. (≡Pyrus harrowiana Balf. f. & W.W. Smith) in fruits and strong branchlets.
Sorbus insignis was first published by J. D. Hooker and C B. Clarke (
Sorbus harrowiana was described on a single George Forrest collection from the Yunnan, south-western China. In the protologue,
Herbarium specimens were studied at A, CAS, CDBI, GH, E, IBSC, K, KATH, KUN, LBG, MO, P, PE, TI and WU (abbreviations according to
Normality of the QN standardised variables was tested using the Shapiro and Wilk test (
Both the non-parametric Wilcoxon signed-rank tests on untransformed data and parametric Welch Two Sample T-tests on log10 transformed data found highly significant (p < 0.001) differences between S. harrowiana and S. insignis in terms of middle leaflet length, width and l/w ratio (Fig.
Box plot of comparisons between S. harrowiana and S. insignis in middle leaflet length, width and l/w ratio. Significant differences found upon analysis using non-parametric Wilcoxon rank sum test on untransformed data (Wilcoxon) and parametric Welch Two Sample T-test on log10 transformed data (T-test) are noted within the figures (*** = p < 0.001).
≡Pyrus insignis Hook. f., Fl. Brit. India 2(5): 377. 1878.
India. Sikkim: 8000–11000 ft [2438–3353 m alt.], J.D. Hooker & C.B. Clarke s.n. (holotype: K (K000758177 [image!])). Fig.
Trees or shrubs. Stems greyish-brown; bark grey; branchlets greyish-brown when old; rusty brown tomentose when young, glabrous when old; winter buds narrowly ovoid, 1.0–1.8 cm long, scales initially puberulent, glabrate later; apex shortly acuminate or acute, brownish. Leaves pinnately compound, 15–20 cm long; stipules persistent, suborbicular, sometimes lobed, 1–2 cm wide, margin entire or serrate with pointed teeth; petiole 1.7–4.0 cm long, glabrous; rachis sparsely tomentose, glabrous when old; leaflets 7–16, at intervals of 1–2 cm long, oblong or oblong-lanceolate, 5–8 × 1.5–2.0 cm, l/w ratio 3.2–4.2, middle leaflets l/w ratio 3.3–4.0, lateral veins 24–30 pairs, margin slightly revolute and shallowly crenate, base rounded or obliquely cordate, apex obtuse, both surfaces tomentose when young, glabrescent. Inflorescences compound corymbs, 30–80 flowered, 8–12 cm in diam., peduncles sparsely pubescent; pedicels 2–4 mm long, sparsely pubescent; flowers 6–8 mm in diam.; hypanthium abaxially pubescent; sepals triangular, ca. 1.5 mm long, glabrous or somewhat puberulous, apex acute, with reddish dentate glands along margin; petals creamy white, suborbicular, ca. 4 × 3 mm; stamens ca. 20; carpels 3(–4); styles 2 or 3, 2.5 mm. Infructescence sparsely pubescent or glabrous; pomes green when young, white or crimson when mature, globose or ovoid-globose, 5–8 mm in diam., sepals persistent erect; seeds brownish, reniform, 1.5–2.0 mm long; 2n = 34.
Flowering May–June; fruiting Sep–Oct.
Sorbus insignis is distributed in India, Nepal and China (Xizang) (Fig.
China. Xizang province: Motuo, 2900 m alt., 25 Oct 2016, B. Xu et al. YLZB4493 (CDBI); Galung La, 2700 m, 18 Aug 1982, S.Z. Cheng & B.S. Li 0200 (PE).
India. Manipur state: Sirohifurar, 2500 m alt., Jan. 1982, G. Watt 5965 (P); Ching Sow, 2400–2700 m alt., 16 April 1982, G. Watt 6539 (P); Sikkim state: T. Thomson s.n. (E).
Nepal. Eastern Nepal: Sankhuwasabha, 29 Oct 1963, H. Hara et al. 6301809 (TI); Kuwa Pani, 2890 m alt., 23 Aug 1997, S. Noshiro et al. 9755184 (A, E); Kauma, 3130 m alt., 25 Sep 1991, Edinburgh Makalu Expedition 259 (E, KATH); Koping, 3040 m alt., 24 Oct 1991, Edinburgh Makalu Expedition 1019 (E); Jhakpu, 2750 m alt., 26 Sep 1971, P.R. Shikyo & M. Ohsawa 1069 (KATH); Bhyaha, 2880 m alt., 31 Oct 1981, P.R. Shakya 7296 (KATH); Taplejung, 2700 m alt., 30 Sep 1981, P.R. Shakya 6777 (KATH).
≡Pyrus harrowiana Balf. f. & W.W. Smith, Notes Roy. Bot. Gard. Edinburgh 10 (46): 61–62. 1917.
China. Yunnan: Western flanks of the Shweli-Salwin Divide (Tenchong County?), 2800 m alt., 15 Aug 1912, George Forrest 9040 (holotype: E (E00072735 [image!]); isotypes: A (A00046014!), E (E00010858 [image!], E00072736 [image!]), K (K000758123 [image!])). Fig.
Small trees or shrubs. Stems greyish-brown; bark grey to bronze; branchlets glabrous; winter buds conic, 1.5–2.0 cm long, scales glabrous; apex acute, reddish-brown. Leaves pinnately compound, 15–25 cm long; stipules persistent, suborbicular, 1–2 cm, margin toothed; petiole 2.0–4.0 cm long, glabrous; rachis sparsely tomentose, glabrous when old; leaflets 5–7, at intervals of 1–2.5 cm long, oblong, 10–18 × 2.5–3.5 cm, l/w ratio 3.2–4.6, middle leaflets l/w ratio 3.5–4.5, lateral veins 19–21 pairs, margin slightly revolute and shallowly crenate, base rounded or obliquely cordate, apex rounded, both surfaces glabrous. Inflorescences compound corymbs, 30–200 flowered, 12–20 cm in diam., peduncles sparsely pubescent or glabrous; pedicels 3–6 mm, sparsely pubescent or glabrous; flowers 6–9 mm in diam.; hypanthium abaxially pubescent; sepals triangular, ca. 2.0 mm long, glabrous or somewhat puberulous, apex acute, with serrate along margin; petals creamy white, suborbicular, ca. 4 × 4 mm; stamens ca. 15–25; carpels 3(–4); styles 2–4, 2–4 mm. Infructescences sparsely pubescent or glabrous; pomes creamy-white rarely pink, globose or ovoid-globose, 5–7 mm in diam., sepals persistent erect; seeds brownish, reniform, 1.5–2.0 mm long; 2n = 34.
Flowering May–July; fruiting Sep–Oct.
Sorbus harrowiana is distributed in China and Myanmar (Fig.
China. Yunnan province: Deqin, Cizhong, 2800 m alt., 8 Oct 1959, K.M. Feng 23997 (KUN, PE); Fugong, Lumadeng Xiang, 3100 m alt., 13 Aug 2005, Gaoligong Shan Biodiversity Survey (G.S.B.S.) 27252 (CAS, GH, KUN); Biluo Mountain, 2800 m alt., 28 May 1982, Qinghai-Tibet Expedition 6939 (KUN, PE); Yaping pass, 2884 m alt., 2 May 2002, G.S.B.S. 20209 (CAS, E, GH, KUN, MO); Yaduo Cun, 2700 m alt., 6 Aug 2005, G.S.B.S. 26500 (CAS, GH, KUN); Shibali, 2700 m alt., 15 Aug 2005, G.S.B.S. 28304 (CAS, GH, KUN); G.S.B.S. 28409 (CAS, GH, KUN); Gongshan, Bingzhongluo, 2530 m alt., 1 Sep 2006, G.S.B.S. 31826 (CAS, E, GH, MO, KUN); 2700 m alt., 25 Jul 1982, Qinghai-Tibet Expedition 7512 (KUN, PE); Zguziluo, 2800–3000 m alt., 25 Jun 1978, Bijiang Expedition 1009 (KUN); Champutung, 3000 m alt., Oct 1935, C.W. Wang 67581 (A, KUN, LBG, NAS, PE, PE, WUK); Dulongjiang, 2700 m alt., 21 May 1991, Dulongjiang Expedition 7022 (KUN); Kongdang, 3030 m alt., 28 Sep 2002, G.S.B.S. 16655 (CAS, E, GH, KUN); Labadi, 2970 m alt., 30 Sep 2002, G.S.B.S. 16792 (CAS, E, GH, KUN); Pula river, 3100 m alt., 3 Oct 2002, G.S.B.S. 16906 (CAS, E, GH, KUN); Fucai, 2780 m alt., 1 Sep 2006, G.S.B.S. 31772 (CAS, E, GH, MO, KUN); Yidongwei, 2530 m alt., 1 Sep 2006, G.S.B.S. 31826 (CAS, E, GH, MO, KUN); Mangzhou Wadi, 3010 m alt., 12 Aug 2006, G.S.B.S. 33217 (CAS, E, G, KUN); Qi-Qi Nature Reserve Station, 3200 m alt., 16 Oct 1996, G.S.B.S. (1996) 7803 (E); Dong Shao Fang, 3100 m alt., 21 Sep 1997, G.S.B.S. (1997) 9495 (E, MO); Danzhu river, 2750 m alt., 1 Jul 2000, H. Li et al. 11855 (CAS, E GH, KUN); Dulong Jiang valley, 2770–3050 m alt., 15 Jul 2000, H. Li et al. 12614 (CAS, E, GH, MO, KUN); Su Ki Tung, 1923, J. Rock 10161 (A); Mt. Kenyichunpo, 10000 ft [3048 m alt.], Jul 1923, J. Rock 22068 (A, E); Cikai, 07 Oct 1940, K.M. Feng 7946 (KUN, PE); East Check Point, 2700 m alt., 22 Jul 1982, K.M. Feng 8226 (KUN, PE); Wangtzang, 2800 m alt., 13 Sep 1938, T.T. Yü 20216 (A, E, KUN, PE); Swangchiang, 13 Jul 1938, T.T. Yü 22088 (A, E, KUN, PE); Lushui, 2800 m alt., 6 Jul 2016, Meng Li et al. GYD0058 (CDBI); Tenchong, Mingguang Xiang, 19 May 2006, 3000–3050 m alt., G.S.B.S. 29157 (CAS, E, GH, KUN); Zizhi Cun, 2750–2850 m alt., 19 May 2006, G.S.B.S. 29224 (CAS, E, GH, MO, KUN); Jiangao Shan, 3020 m alt., 23 May 2006, G.S.B.S. 30546 (CAS, E, GH, MO, KUN); Weixi, 2900 m alt., 13 Oct 1934, H.T. Tsai 59790 (A, IBSC, KUN, P, PE); 2800 m alt., 20 Oct 1934, H.T. Tsai 59902 (A, IBSC, KUN, LBG, PE); Biluo Snow Mountain, 3250 m alt., 11 Jul 1981, PE Hengduan Mountain Collection Team 01402 (PE); Cangjiang river, 3300 m alt., 18 May 1940, K.M. Feng 3965 (KUN, PE); Baimaluo, 3200 m alt., 3 June 1940, K.M. Feng 4429 (KUN, PE); Yanwa, 3600 m alt., 11 May 1960, Kunming Workstation of Institute of Botany 8375 (KUN, PE); Kangpucheda, 3000 m alt., 8 Oct 1956, P.I. Mao 385 (KUN, PE); Magelo, 23 Aug 1956, P.I. Mao 401 (KUN, PE); Bading, 3500 m alt., 11 May 1982, Qinghai-Tibet Expedition 6434 (PE); Yunlong, Nu Shan, 2 Nov. 1993, K.D. Rushforth 2663 (E); Xizang province: Chayu, 10000–11000 ft [3048–3353 m alt.], June 1922, G. Forrest 21806 (A, E, P); Oct. 1922, G. Forrest 22870 (A, E).
Myanmar. Kachin state: Myitkyina, 3050 m alt., 19 Oct 1919, R. Farrer 1403 (E); G. Forrest 24481 (E, PE); Chimili, G. Forrest 26813 (A, E); G. Forrest 27541 (A, E); G. Forrest 29775 (E, PE); Putao, 2800 m alt., 16 May 1953, F. Kingdon-Ward 20921 (E); Tata Bum, 3000 m alt., 19 June 1953, F. Kingdon-Ward 21009 (A, E); Trails above Camp 3, 3000–3140 m alt., 22 Oct 2013, Hponyin Mountains Expedition 206A (E); Adung velly, F. Kingdon-Ward 9568 (A).
Note. George Forrest made seven major expeditions to western China and north-eastern Myanmar during 1917 and 1931, with over 30,000 collections being made. In these expeditions, G. Forrest collected at least 23 specimens of Sorbus harrowiana, of which 15 lacked locality information. However, from limited collection information, we are able to broadly georeference these 15 specimens to four different regions (as he mentioned in the collection record), i.e. (1) China: Yunnan: Shweli-Salwin divide, G. Forrest 15888 (E, P), G. Forrest 16101 (E), G. Forrest 18506 (E), G. Forrest 24373 (E, P, PE), G. Forrest 26778 (A, E); (2) China: Yunnan: N’mai kha-Salwin divide, G. Forrest 18527 (E, P), G. Forrest 18753 (E); (3) China: Yunnan: Salwin-Kui Chiang divide, G. Forrest 25687 (E, PE), G. Forrest 25768 (E); (4) China: Yunnan, G. Forrest 19874 (E), G. Forrest 20849 (E), G. Forrest 20869 (E, P), G. Forrest 21806 (A, E, P), G. Forrest 29015 (E, PE), G. Forrest 30374 (E, PE). The specimens examined by us also covered those four regions.
1 | Leaflets, Inflorescences and infructescence pubescent | S. helenae Koehne |
– | Leaflets, inflorescences and infructescence glabrous | 2 |
2 | Leaflets 7–16 per compound leaf, 5–8 × 1.5–2.0 cm, oblong or oblong-lanceolate, lateral veins 24–30 pairs, both surfaces tomentose when young, glabrescent with age | S. insignis |
– | Leaflets 5–7 per compound leaf, 10–18 × 2.5–3.5 cm, oblong, lateral veins 19–21 pairs, both surfaces glabrous | S. harrowiana |
We thank the curators of A, CAS, CDBI, GH, E, IBSC, K, KATH, KUN, LBG, MO, NAS, P, PE, TI, WU and WUK for allowing us to examine specimens or use their images of specimens. This study was supported by grants from NJFU Scientific Research Starting Foundation (Grant No. GXL2018039) and National Natural Science Foundation of China (Grant No. 32000165) to Meng Li.
Table S1. Accessions of herbarium specimen for measurements
Data type: measurement
Explanation note: .