Heliotropium indicum L., Sp. Pl.: 130. 1753.

Rueangsawang, Kanokorn & Chantaranothai, Pranom, 2023, A taxonomic synopsis of Heliotropiaceae and new combinations in Heliotropium from Thailand, PhytoKeys 232, pp. 189-210 : 189

4. Heliotropium indicum L., Sp. Pl.: 130. 1753.

Fig. 4D-F

Type.

India utraque, Herb. Hermann 1: 9, no.70 (lectotype, designated by Mill in Cafferty and Jarvis 2004, p. 802: BM [BM00061256!]).

Distribution.

North America, South America, Pakistan, India, Sri Lanka, China, Myanmar, Taiwan, Japan, Laos, Cambodia, Vietnam, Thailand (Fig. 1I ), Sumatra, Malaysia, Java, Borneo, Australia.

Ecology.

Common on sandy soil near stream or open areas, rice fields, roadsides; 50-1,000 m alt., flowering and fruiting from January to April.

Specimens examined.

Thailand, Northern: Mae Hong Son, Mueang, 256 m alt., 10 Sept 2013, Lakoet 0352 (QBG); 350 m alt., 18 June 1973, Geesink et al. 5937 (AAU, BKF, E, K, TCD); Chiang Mai, Doi Sa Ket, 12 Dec 2007, Warintorn 07 - 105 (QBG); San Kamphang, 325 m alt., 10 July 1996, Panatkool et al. 37 (BKF); Doi Suthep, 300 m alt., Hosseus s.n. (K); ibid., 1,000 m alt., 12 May 1915, Winit 402 (K, E); ibid., 1,000 m alt., 5 Jan 1911, Kerr 1845 (BM, K, E); Hod, 8 Sept. 1996, BGO Staff 28 (QBG); Ban Chang Keong, 488 m alt., 28 May 2019, Pingyot 276 (QBG); Chiang Rai, Thoeng, 12 Feb 2011, Norsaengsri & Tathana 7444 (QBG); San Pa Tong, 325 m alt., 26 Apr 1988, Maxwell 88 - 521 (BKF, CMUB); Phayao, Ban Khun Kam Lang, Pong, 400 m alt., 19 May 2017, Pongamorkul 6201 (QBG); Nan, Na Noi, 9 Apr 2018, Khattiyot et al. 778 (QBG); Huai Haeng, 318 m alt., 26 Apr 2017, Muaengyen 2011 (QBG); Lampang, Sop Prap, 28 Feb 2012, Norsaengsri et al. 9055 (QBG); Uttaradit, Nam Pat, 22 Mar 2011, Romklao Botanical Garden 0224/2554 (QBG); Tak, Mae Sot, 22 July 1959, Floto 7653 (C); Tha Song Yang, 15 May 2007, Pooma et al. 6785 (BKF, E, L); Phitsanulok, Tham Pha Phon Non-Hunting Area , 5 Mar. 2012, Maknoi 4627 (QBG); Wat Hua Khao, 31 Jan 2012, Maknoi 4565 (QBG). North-eastern: Loei, Na Haeo, Yaa Ngoung Chaang, 31 July 1995, Nanakorn et al. 4077 (QBG); Phu Kradueng, 27 Aug 1988, Tamura T-60450 (BKF); Sithan, Huai Yang, 300 m alt., 21 Feb 1958, Ploenchit 1342 (BKF); Bueang Kan, Mueang, 27 Dec 2011, Norsaengsri & Tathana 8581 (QBG); Maha Sarakham, Kosum Phisai, 3 May 2001, Norsaengsri et al. 1440 (QBG); Ban Maong Ai, 130 m alt., 3 Apr 2001, Norsangsri et al. 1440 (QBG); Chiang Yuen, 14 Apr 2018; Khon Kaen, Chum Phae, 2 Sept 1967, Shimizu et al. T-8685 (BKF, E, TCD). Eastern: Nakhon Ratchasima, Bua Yai, 18 Mar 2009, Norsaengsri 5135 (QBG); Ban Chum Sang, 25 May 1929, Nai Noe 277 (ABD, BM, BK, K); Ubon Ratchatani, Khong Chiam, 170 m alt., 25 May 2001, Greijmans 90 (BKF); Phibun Mangsahan, 250 m alt., 9 Dec 1982, Koyama et al. T-30698 (AAU, BKF); Det Udom, 270 m alt., 10 Dec 1982, Koyama et al. T-30778 (BKF); Buri Ram, 7 Aug 1970, Sutheesorn 2065 (BK); Ban Na, Suwan Naphum, 16 Aug 1982, Sutheesorn & Saraphunphichit 5354 (BK). South-western: Kanchanaburi, Si Sawat, 150 m alt., 6 Nov 1971, van Beusekom et al. 3955 (BKF, C, K); Thum Pha, 13 Dec 1961, Phengklai 228 (BKF); Kwae Noi, 30 Apr 1946, Wichian 304 (K); Na Ta Hom, 23 Apr 1965, Chantanamuck 1094 (BK); Prachuap Khiri Khan, 18 Aug 1967, Shimizu et al. T-7689 (AAU, BKF, E, K). Central: Chat Nat, 5 Mar 1958, Sørensen et al. 1922 (E, C); Pathum Thani, 50 m alt., 12 Mar 1958, Smitinand 4444 (BKF); Nakhon Nayok, Khao Yai, 1,000 m alt., 5 May 1964, R.S. 116 (BKF); 40 m alt., 6 Aug 1970, Phengklai et al. 3748 (BKF); Nonthaburi, Sai Maa Tai, 14 Apr 1992, Puudjaa 65 (BKF); Bangkok, 5 July 1920, Marcan 293 (BM, K); 27 Oct 1919, Kerr 3840 (ABD, BM, C, K); 19 Apr 1926, Lakshnakara 52 (BK); Sept 1921, Smith 49 (BK); 1899, Zimmermann s.n. (K); Ang Thong, 30 Dec 1929, Put 2595 (AAU, ABD, BK, BM, K). South-eastern: Chachoengsao, Phanom Sarakham, 50-100 m alt., 1 Oct 1984, Murata et al. T-37042 (BKF); Chon Buri, Si Racha, 30 Nov 1927, Collins 2025 (ABD, BM, BK, K, TCD); Chanthaburi, 8 Apr 1959, Sørensen et al. 7214 (C). Peninsular: Chumphon, 31 Jan 1958, Sørensen et al. 829 (BKF, C); Ranong, Kapoe, 19 Jan 2016, Kertsawang 3937 (QBG); Satun, La-ngu, Ko Kabeng, 11 Apr 2003, Phengklai et al. 13650 (BKF); Songkhla, 21 Aug 1995, Larsen et al. 45836 (AAU, BKF); Satun, Terutao, 5 Mar 1966, Hansen & Smitinand 12542 (BKF, C) .

Vernacular.

Ya nguang chang (หญ้างวงช้าง).

Diagnostic characters.

Heliotropium indicum is likely native to tropical America and introduced in all the tropical regions of the world. This species is also a common weed with medicinal properties ( Dash and Abdullah 2013). It is most easily recognised by ovate to elliptic leaves with strigose and stiff hairs on both surfaces, truncate or obtuse leaf base, irregularly undulate leaf margins, white to purple or purplish corollas with a yellow-orange throat inside and fruits are deeply 2-lobed with apical divergent lobes.

Figures

Figure 1. Distribution of Heliotropiaceae from Thailand, based on the specimens examined.

Figure 4. Species of Heliotropium from Thailand A-C H. foertherianum Diane & Hilger A inflorescence B habit C flowers D-F H. indicum L. D inflorescences E habit and inflorescence F young fruits. Photos by Kanokorn Rueangsawang.