Phlogacanthus jenkinsii C.B. Clarke (1885: 511)

Maity, Rohan, Sawmliana, Mal & Dash, Sudhansu Sekhar, 2022, Rediscovery of Phlogacanthus jenkinsii (Acanthaceae) from India after 140 years, Phytotaxa 573 (2), pp. 286-292 : 287-289

Phlogacanthus jenkinsii C.B. Clarke (1885: 511) [Figs. 1,2].

Lectotype:—(designated by Maity & Dash 2020): INDIA. Assam: s.d., Jenkins s.n. (K, barcode K000950015, digital image!).

Description: — Shrubs, up to 3 m tall; stem stout, quadrangular, sometimes ridged, pubescent when young, glabrous on maturity, green–red; leaves elliptic–lanceolate, 4–17(20) × 1.5–4.5(7) cm, apex acute–caudate, entire, cuneate, green, glabrous on both surface, petiolate; petiole ca. 4 cm long; inflorescence axillary, compact thyrse, ca. 7 cm long, many-flowered, peduncled; peduncle up to 4 cm long, puberulent; flowers zygomorphic, pedicellate; pedicel up to 5 mm long, puberulous; bracteate; bract 1 per flower, up to 2 mm long, linear, green, pubescent; bracteolate; bracteoles 2 per flower, subulate, ca. 1 mm long, green, dense pubescent; calyx campanulate, 5-lobed, densely grey pubescent; tube very short, ca. 2mm long; lobes linear–lanceolate, up to 1 cm long; corolla 2-lipped, slightly curved, 2–2.5 cm long, orange-yellow, pubescent outside; tube broader towards apex, 1.5–1.8 cm long, slightly curved; upper lip ca. 5 mm long, 2-lobed; lower lip ca. 2 mm long, 3-lobed; stamens 2, slightly exerted; filaments ca. 1.5 cm long, orange, mostly glabrous, filiform except base; base curved, slightly broader than apex, pubescent; anthers oblong, ca. 3 mm long, parallel, introrse, brown–greenish; staminodes 2, very minute, obscure, ridge like, only be seen in most mature flowers; ovary ovoid-oblong, ca. 4 mm long, green, glabrous, 2-chambered, 12-ovuled; style filiform, curved at apex, green–orange, glabrous; stigma minute, 2-cleft; fruits not seen.

Vernacular name:—Kawldai-Par-Eng (Mizo)

Phenology:—Flowering from January to March.

Distribution:— India (Assam, Manipur, Mizoram) and Myanmar.

Specimens examined:— INDIA. Mizoram: Rulchawm , ca. 1100 m, 27 January 2022, M. Sawmliana s.n., ( ARUN). Assam: 1829, s.coll., s.n., (K); Manipur: 1881–1882, G. Watt 7360, ( CAL) . MYANMAR. Katha State: Kadu Hill , 3000 ft, 23 February 1910, J.H. Lace 5121 (E) ; “Upper Burmah, Valley of the Taping”, 2000 ft, February 1914, G. Forrest 12170 (E) ; Sumprabum Sub-Division, “Two miles north west of Kanang”, 6500 ft, March 1962, J. Keenan, U Tun Aung & U Tha Hla 3900 (E) .

Threat assessment as per IUCN guidelines ( IUCN, 2012a, 2012b, 2019):— The species was known from five collections from Assam and Manipur without any precise locality. During our present study, we have collected the species from four localities in and around Rulchawm, Mizoram. Based on the present and past collections the area of occupancy (AOO) is calculated to 500 km 2 with very limited distribution at less than 5 locations where the habitats are continuously shrinking due to developmental works. Therefore, the taxon is assessed here as endangered [EN B2ab(iii)] in India.