Strobilanthes phyllostachya Kurz

Kladwong, Pornchai & Chantaranothai, Pranom, 2024, Notes on Strobilanthes (Acanthaceae) with capitate inflorescences in Thailand, PhytoKeys 244, pp. 89-126 : 89-126

20. Strobilanthes phyllostachya Kurz , J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 40 (1): 75. 1871.

Figs 8 , 11 C

Sericocalyx phyllostachyus (Kurz) Bremek. , Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk., Sect. 2. 41 (1): 163. 1944.

Type.

Myanmar, Bago Region [Beeliz], Brandis s. n. (syntype K! [without barcode]).

Distribution.

Myanmar, Thailand.

Ecology.

Near stream in evergreen forest or bamboo forest; 10–1,000 m alt., flowering and fruiting from November to March.

Selected specimens examined.

Thailand, Northern: Mae Hong Son, Mae Sariang, 400 m alt., 21 Feb 1982, Wongprasert 6 ( BKF- 2 sheets, K, L, P); ibid., Huai Ngae, 350 m alt., 14 Feb 1971, Smitinand & Boonkird 11422 ( BKF); 450 m alt., 13 Jan 1988, Santisuk 6668 ( BKF- 2 sheets); ibid., Salawin WS, Huai Ka Han, 500 m alt., 23 Mar 2006, Watthana & Wongnak 1860 ( QBG); ibid., Sob Moei, 950 m alt., 24 Jan 2015, Pongamornkul 4782 ( QBG); ibid., Mae Ngao NP, 13 Jan 2015, Tanming 757 ( QBG); Tak, Mae Ngo NP, 395 m alt., 23 Dec 2010, Suksathan et al. 5336 ( L); ibid., Tha Song Yang, 22 Mar 2006, Pooma et al. 6226 ( AAU, BKF- 2 sheets, QBG); South-western: Kanchanaburi, Thong Pha Phum, 14 Dec 1993, Parinya et al. 364 ( BK); ibid., Wangka, Kwae Noi River Basin, 150 m alt., 13 May 1949, Kostermans 412 ( K).

Preliminary conservation status assessment.

This species has an Extent of Occurrence ( EOO) of 10,101.500 km 2 and an Area of Occupancy ( AOO) of 28.000 km 2 and is assessed as Vulnerable ( VU), B 1 a, b (i, ii, iii) following IUCN (2022). This species grows near streams in evergreen forest or bamboo forest with a few records. The changes of the habitat through increasing droughts and fire are likely to lead to the decline of S. phyllostachya .

Notes.

Strobilanthes phyllostachya is distinguishable from S. squalens S. Moore by its elliptic bract and hairlessness on the outside of the corolla. This species was formerly only known from Myanmar ( Kurz 1871; Wood et al. 2022), but is now newly recorded from the Northern and Southwestern floristic regions of Thailand.

Figures

Figure 8. Strobilanthes phyllostachya Kurz A stem B leaves and inflorescences C bracts D corolla. Photo by P. Suksathan.

Figure 11. Distribution maps of Strobilanthes with capitate inflorescence in Thailand A S. graminea J. B. Imlay, S. hypomalla Benoist and S. kerrii Craib B S. paniculiformis J. R. I. Wood, S. paniculata (Nees) Miq. and S. phengklaii Kladwong & Chantar. C S. phyllocephala J. R. I. Wood & Scotland, S. phyllostachya Kurz and S. serpens (Nees) J. R. I. Wood & Scotland D S. speciosa Blume and S. squalens S. Moore.