Euploca strigosa (Willd.) Diane & Hilger, Bot. Jahrb. Syst. 125(1): 49. 2003.

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

5. Euploca strigosa (Willd.) Diane & Hilger, Bot. Jahrb. Syst. 125(1): 49. 2003.

Fig. 3D-F

Heliotropium strigosum Willd., Sp. Pl., ed. 4, 1(2): 743. 1798. Type: Ghana [Guinea], Isert s.n. (holotype B [B-W 219/3253, microfiche], isotypes C [C10003972!], P [P-JU6571 image!]).

Lithospermum chinense Hook. & Arn., Bot. Beechey Voy.: 202. 1837. Type: China, Canton, Vachell 286 (holotype E [E00369167!]; isotype BR [BR0000006966485 image!]).

Type.

Based on Heliotropium strigosum Willd.

Distribution.

Africa, Afghanistan, Pakistan, India, Nepal, Bhutan, Myanmar, Laos, Cambodia, Vietnam, China (Hainan, Kwangtung), Thailand (Fig. 1E ), Malesia, Australia.

Ecology.

Open area of bare rock in dry dipterocarp and dry open deciduous forests; 50-400 m alt., flowering and fruiting from April to November.

Specimens examined.

Thailand, North-eastern: Sakon Nakhon, Phu Phan NP, 400 m alt., 6 Aug 2004, Nielsen et al. 1542 (BKF); Phrae, Ban Nun, Song, 193 m alt., 25 June 2012, Norsaengsri & Tathana 9480 (QBG). Eastern: Surin, Nadi, 17 May 1965, Sakol 224 (BK); Ubon Ratchathani, Chiet, 100 m alt., 21 May 1932, Kerr 21537 (BK, BM, E, K). Central: Chai Nat, Utapao, 20 Sept 1930, Kerr 19692 (ABD, BM, BK). South-western: Kanchanaburi, 5 km west of Thong Pha Phum Town , 16 Oct 2015, Tanming 873 (QBG); Thong Pha Phum, along route 323, 4 km, 240 m alt., 29 Nov 1982, Koyama et al. T-30469 (BKF); Prachinburi, Watananakorn, 23 July 1987, Paisooksantivatana & Sangkhachand 2109-87 (BK). South-eastern: Sa Kaeo, Aranyaprathet, 50 m alt., 3 Apr 1930, Kerr 19575 (BM, BK, K). Peninsular: Songkhla, Padang Besar, 50 m alt., 24 Dec 1927, Kerr 13602 (BM, BK, K) .

Diagnostic characters.

Euploca strigosa is most similar to E. paniculata in having spike-like inflorescences arranged in one rank that can elongate up to 10 cm long, but it differs in the stem being a prostrate to many-branched (vs. erect unbranched to few-branched stem in E. paniculata ), the narrowly elliptic leaves with strigose hairs on both surfaces, 5-10 × ca. 3 mm (vs. linear leaves with greyish tomentose hairs, 7-40 × 1-2 mm in E. paniculata ).

Figures

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

Figure 3. Species of Euploca from Thailand A-C E. paniculata (R. Br.) M. W. Frohl. & M. W. Chase A habit and inflorescences B inflorescence C young fruits D-F E. strigosa (Willd.) Diane & Hilger D inflorescence E habit F habit and inflorescences. Photos by Kanokorn Rueangsawang.