Hedyotis laotica (Pitard) Wangwasit & Chantar., 2015

Wangwasit, Khanit & Chantaranothai, Pranom, 2015, Notes on Hedyotis L. (Rubiaceae) from Thailand, Phytotaxa 206 (1), pp. 47-52 : 51

publication ID	https://doi.org/ 10.11646/phytotaxa.206.1.8
DOI	https://doi.org/10.5281/zenodo.13642431
persistent identifier	https://treatment.plazi.org/id/039F1A09-A661-FF8E-EF88-83FAFED9FB8C
treatment provided by	Felipe
scientific name	Hedyotis laotica (Pitard) Wangwasit & Chantar.
status	comb. nov.

Treatment

Hedyotis laotica (Pitard) Wangwasit & Chantar. View in CoL , comb. nov.

Basionym: Oldenlandia laotica Pitard (1922: 123) View in CoL . Type: — LAOS. expedition du Mékong, anno 1866–1868, Thorel s.n. P04009758 (lectotype P, image!, designated here).

Thailand: — Sakon Nakhon: Phu Phan National Park, Laan Sao Ae , 19 Oct. 1990, P. Chantaranothai & J. Parnell 90/796 (K, TCD) ; the same locality, 23 Nov. 2010, K. Wangwasit 101123-7 (KKU) ; Khon Kaen: along route 2, near Nam Phong , 19 Sept. 1984, N. Fukuoka T-36206 (BKF) ; Nakhon Ratchasima: Bua Yai , 2 Nov. 1931, Put 4278 (BM, K) ; Burirum : ca. 130 m, 27 Nov. 1976, C. Phengklai et al. 3482 (BKF) ; Surin: near Cambodian border, ca. 50 km SW of Sangkha, 190 m, 6 Oct. 1984, G. Murata, C. Phengklai, S. Mitsuta, H. Nagamasu & N. Nantasan T-37669 (BKF) ; Si Sa Ket: en route from Si Sa Ket to Ubon Ratchathani, 130–180 m, 10 Oct. 1984, G. Murata, C. Phengklai, S. Mitsuta, H. Nagamasu & N. Nantasan T-38149 (BKF) ; Ubon Ratchathani: along route 217, 20 km W of Ubon, Muang , 200 m, 9 Dec. 1982, H. Koyama, H. Terao & T. Wongprasert T-30627 (BKF) .

Distribution: — Hedyotis laotica is distributed in Thailand and Laos.

Habitat: —It grows in open to semi-shaded grassy fields with sandy soil in deciduous forest.

Phenology: —Flowering in August–December.

Note:—Two collections at P, Massie s.n. (with 4 sheets, P04009756, P04009757, P04009759 and P4009760) and Thorel s.n. (P04009758), are mentioned in the protologue of O. laotica . The specimen of Thorel’s collection has flowers and fruits that are well-preserved; and therefore it is selected as the lectotype here. Hedyotis laotica is placed with Hedyotis because it has septicidally and loculicidally dehiscent capsules, dorsiventrally compressed seeds with a longitudinal hilar ridge and punctiform hilum, in accordance with Wikström et al. (2013). Furthermore, the species is similar to H. tetrangularis and H. ternata , two species placed in Hedyotis s.str. by molecular data (Wikström et al. 2013). They are erect herbs with linear leaves, narrowly triangular stipules, corymbiform inflorescences, and heterostylous flowers. Hedyotis laotica is distinguishable from both H. tetrangularis and H. ternata by its overall pubescence.