Heliotropium intonsum (Kerr) Rueangs. & Chantar., 2023

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

5. Heliotropium intonsum (Kerr) Rueangs. & Chantar. comb. nov.

Fig. 5A

Tournefortia intonsa Kerr, Bull. Misc. Inform. Kew 1940: 185. 1940.

Type.

Thailand, Doi Sutep , ca. 900 m alt., evergreen forest, Kerr 2285 (holotype K [K000998142!]; isotypes BM [BM001209041!], E [E00766166!]) .

Distribution.

Laos, Thailand (Fig. 1J ).

Ecology.

In deciduous forest, evergreen forest, flowering and fruiting from November to February.

Specimens examined.

Thailand, Northern: Mae Hong Son, Pang Mapha, 580 m alt., 26 Feb 1968, Hansen & Smitinand 12741 (AAU, BKF, C, E, K); Chiang Mai, Doi Chiang Dao, 20 Mar 1956, Suvarnakoses 1121 (BKF, K); ibid., 700 m alt., 18 Feb 1958, Sørensen et al. 1312 (BKF); ibid., 23 Dec 1931, Put 4570 (BK, E, K); ibid., 600-800 m alt., 14 Mar 1956, Garrett 1449 (K, L); ibid., 600 m alt., 14 Mar 1956, Garrett 1476 (K, L); ibid., 1,500 m alt., 17 Feb 1958, Smitinand 4218 (BKF); ibid., 525 m alt., 26 Feb 1989, Maxwell 89 - 273 (BKF, CMU, CMUB, L); ibid., 550 m alt., 10 Mar 1990, Maxwell 90 - 294 (CMU); Chiang Rai, Doi Tung, 750 m alt., 15 Feb 2012, van de Bult 1241 (BKF); Mae Sai, Huai Nam Dang, 612 m alt., 13 Jan 2011, Norsaengsri & Tathana 7537 (BKF, QBG); Mae Sai, Ban Phamee, 572 m alt., 15 Feb 2012, Norsaengsri & Tathana 9003 (QBG); Hua Yane, Mae Chan, 25 Jan 1970, Sutheesorn 1438 (BK); Doi Tung, 1,400 m alt., 29 Jan 1989, Bragg 8 (CMU, L); Phrae, Mae Khaen stream, 440 m alt., 5 Jan 1972, van Beusekom, et al. 4636 (C, BKF, K); ibid., 22 Mar 1912, Vanpruck 454 (K); Mae Yom NP, 400 m alt., 15 Dec 1993, Maxwell 93 - 1509 (CMUB, L)]. North-eastern: Phetchabun, Chon Daen, 15 Jan 1969, Vacharapong 304 (BK); Loei, Phu Suan Sai NP, 11 Mar 2008, Maknoi 2029 (BKF, QBG); route to Sam Nuck Bab, 15 May 2008, Maknoi & Srisaga 2302 (BKF, QBG); Tad Hueang waterfall, 1,000 m alt., 16 May 2006, Maknoi 824 (QBG); Na Haeo, 650 m alt., 27 Apr 1995, Nanakorn et al. 3239 (QBG); Khon Kaen, Pha Bhroung Cave , Chum Phae, 14 Feb 1963, Chantanamuck 295 (BK). South-western: Uthai Thani, Huai Haeng, 27 Apr 1963, Kasem 329 (BK). South-eastern: Chanthaburi, Pong Nam Ron, 600 m alt., 12 Jan 1956, Smitinand 3192 (BKF) .

Vernacular.

Ya Nguang Chang Luang (หญ้างวงช้างหลวง).

Diagnostic characters.

Heliotropium intonsum is most similar to H. montanum in its dichotomous branched inflorescences and subsessile pedicels, but differs in the leaves being oblong or elliptic with densely strigose hairs (vs. glabrous to glabrescent ovate-lanceolate leaves in H. montanum ) and both the inflorescences and corollas bear densely greyish tomentose hairs (vs. glabrous in H. montanum ).

Figures

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

Figure 5. Species of Heliotropium from Thailand A H. intonsum (Kerr) Rueangs. & Chantar. B H. montanum (Lour.) Rueangs. & Chantar. Photos by Kanokorn Rueangsawang.