Notes on Strobilanthes (Acanthaceae) with capitate inflorescences in Thailand Author Kladwong, Pornchai 0000-0003-3504-7434 Department of Forest Biology, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand Author Chantaranothai, Pranom 0000-0002-5065-6169 Department of Biology, Center of Excellence on Biodiversity (BDC) and Applied Taxonomic Research Center (ATRC), Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand & Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 AE, UK text PhytoKeys 2024 2024-07-09 244 89 126 journal article 299637 10.3897/phytokeys.244.124260 0fa35208-01f9-4ac2-a8aa-c616738c6e6c 21. Strobilanthes serpens (Nees) J. R. I. Wood & Scotland , Kew Bull. 77: 834. 2021 . Fig. 11 C Ruellia serpens Nees, Prodr. [ A . P . de Candolle] 11: 145. 1847. Type: Indonesia [insular Java ], Tjiserae, 1826, Blume s. n. ( holotype GZU [ GZU 000250312 image!]; isolectotypes B [ B 101182406 image!], L [ L 0065807!]). Hemigraphis serpens (Nees) Boerl. , Handl. Fl. Ned. Ind. 2 (2): 658. 1899 . Type: Based on Ruellia serpens Nees. Hemigraphis hispidula Craib , Bull. Misc. Inform. Kew 1913 (6): 203. 1913 . Type: Thailand , Nan , 21 Feb 1912 , Kerr 2383 a ( lectotype K [ K 000882585!] designated here; isolectotype E [ E 00273431!]), syn. nov. Sericocalyx hispidulus (Craib) Bremek. , Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk., Sect. 2. 41 (1): 163. 1944. Type: Based on Hemigraphis hispidula Craib. Hemigraphis ridleyi C. B. Clarke , J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 74 (3): 652. 1908 . Type: Malaysia , Pahang , Jerantut, Kuala Tembeling, Aug 1891 , Ridley 2180 ( holotype SING [ SING 0027181 image!]). Type. Based on Ruellia serpens Nees Distribution. Thailand , Malaysia , Singapore , Indonesia . Ecology. In grass thickets and meadows or by streams under the shade of mixed deciduous and evergreen forests; 10–1,250 m alt., flowering and fruiting from June to May. Selected specimens examined. Thailand , Northern: Chiang Rai , Doi Luang NP, 580 m alt., 3 Nov 2015 , Muangyen 217 ( QBG ); Chiang Mai , Mae Taeng, Pong Dueat, 825 m alt., 19 Nov 1992 , Maxwell 92-742 ( CMUB , L ); Nan , Tha Wang Pha, 500 m alt., 14 Nov 1993 , Larsen et al. 44347 ( AAU ); ibid., Huai Mae Sakawn, between Phrae and Nan , ca. 427 m alt, 15 Feb 1912 , Kerr 2383 ( E , K ); ibid., common in Jungle, 21 Feb 1912 , Kerr 2383 a ( E ); Phitsanulok , Thung Salang Luang NP, 600 m alt., 25 July 1996 , Larsen et al. 885 ( AAU , BKF ); Kamphaeng Phet , Klong Klung, 200 m alt., 1 June 1922 , Kerr 6044 ( BK , K ); North-eastern: Phetchabun , Nam Nao NP, 11 June 1964 , Chantanamuck 751 ( BK ), Loei , Na Haew, 1,000 m alt., 26 Apr 1994 , Nanakorn et al. 3168 ( QBG ); ibid., Phu Kradueng NP, Phen Phop Mai Waterfall, 1,230 m alt., 4 Sept 1988 , Tsuchiya & Tamura 60534 ( BKF ); Khon Kaen , Chum Phae, Pha Nok Khao, 400 m alt., 26 Nov 1965 , Tagawa 294 ( BKF , K , L ); ibid., Phu Pha Man NP, Nakarat Cave, 483 m alt., 25 July 2010 , Norsaengsri & Thangson 6950 ( QBG ); South-western: Kanchanaburi , Huai Bankao, 800 m alt., 13 Nov 1971 , van Beusekom et al. 3758 ( BKF , K , L ); ibid., Sai Yok, Thung Kang Yang, 5 July 1963 , Larsen 10516 ( BKF , L ); ibid., Sangkhla Buri , Mueang Cha area, 800 m alt., 8 July 1973 , Maxwell 73-218 ( AAU , BK ); Ratchaburi , Chom Bueng, Ban Baw, 100 m alt., 26 Mar 1975 , Maxwell 75-332 ( AAU , BK ); ibid., Thung Kang Yang, 350 m alt., July 1963 , Larsen et al. 10517 ( AAU ); South-eastern: Chon Buri , Si Racha, 15 Nov 1926 , Put 458 ( BK , K ); Chanthaburi , Pong Nam Ron, Khao Soi Dao, 250 m alt., 5 May 1975 , Maxwell 75-485 ( AAU ); Peninsular: Chumphon , Sawi, 9 Sept 1927 , Put 1023 ( BK , K ); Ranong , Kra Buri , Nam Chut, 29 Jan 1927 , Kerr 11704 ( BK , K ); La-un, 10 m alt., 2 Jan 1929 , Kerr 16493 ( BK , K ); Krabi , Khao Panom Bencha, 24 Oct 1991 , Larsen et al. 42533 ( AAU ); Nakhon Si Thammarat , Lan Saka, 50 m alt., 25 Apr 1928 , Kerr 15384 ( BK ); Trang , Khao Chong, 200 m alt., 12 Aug 1975 , Maxwell 75-767 ( AAU ); Songkhla , Rattaphum, Boriphat Waterfall, 100–200 m alt., 19 Oct 1991 , Larsen et al. 42390 ( AAU , BKF ); ibid., 250 m alt., 16 Aug 1984 , Maxwell 84-67 ( BKF , L ). Preliminary conservation status assessment. This species has an Extent of Occurrence ( EOO ) of 399,832.702 km 2 and an Area of Occupancy ( AOO ) of 100.000 km 2 and is assessed as Least Concern ( LC ) following IUCN (2022 ). Notes. Strobilanthes serpens differs from S. hirta Blume in having petioles which are 2–3.5 cm long, obovate bracts and white anthers. Strobilanthes hirta has very short or sessile petioles, ovate-elliptic bracts and purplish-red anthers. Hemigraphis hispidula was described by Craib (1913) . However, after investigation of type and non-type specimens from Thailand , we find that this species has many characteristics in common with S. serpens . Therefore, H. hispidula is placed as a synonym of S. serpens . The original protologue of H. hispidula was based on Kerr 2383 and Kerr 2383 a ( Craib 1913 ). There are two duplicates of Kerr 2383 one at E [ E 00273430] and the other at K [ K 000882584] and there are two duplicates of Kerr 2383 a one at E [ E 00273431] and the other at K [ K 000882585]. All are in good shape: we designate the sheet K 000882585 as the lectotype because it has more mature stems and leaves.