Phlogacanthus paniculatus (T. Anderson) Imlay (1939: 128)

Do, Hai Van, Nguyen, Mai Thi, Nguyen, Huong Thi Thanh, Choudhary, Ritesh Kumar & Deng, Yunfei, 2018, An updated taxonomy of the genus Phlogacanthus (Acanthaceae) in Vietnam, Phytotaxa 372 (2), pp. 167-175 : 168

Phlogacanthus paniculatus (T. Anderson) Imlay (1939: 128) . ( Figs. 1 & 2 )

= Cystacanthus paniculatus T. Anderson (1867: 458) .

Type:— MYANMAR. Moulmein, T.Lobb s. n. ( CAL, K!).

Shrubs to 1 m tall. Stems 4-angled, stout, glabrous; young branches winged. Petiole 1–1.7 cm; leaf blade oblong to oblong-lanceolate, 6–12 × 1.5–4.5 cm, abaxially pubescent along veins, adaxially glabrous, secondary veins 6–8 on each side of midvein, base attenuate and decurrent onto petiole, margin undulate to crenulate, apex acuminate. Thyrses terminal, to 13 cm, many-flowered; rachis densely villous with gland-tipped trichomes; bracts oblong–lanceolate, shorter than calyx, gland-tipped pubescent, caducous; bracteoles similar to bracts. Pedicel 4–5 mm, gland-tipped pubescent. Calyx 8–14 mm, outside gland-tipped pubescent, inside slightly pubescent; lobes lanceolate, 7–13 × 0.5–1 mm, equal, apex acute. Corolla white or light purple, 2–2.5 cm; bent to 90º and abruptly inflated at middle, ventricose, outside gland-tipped pubescent, inside glabrous with purple stripes; limb 2-lipped; lower lip 3-lobed with lobes orbicular, subequal, patent; upper lip 2-lobed with lobes orbicular, equal. Stamens two, included; filaments barbate; anther thecae oblong, ca. 1 mm, connective barbate; staminodes very small. Ovary pubescent, with 4 ovules per locule; style 1.3–1.8 cm, glabrous or pubescent; stigma slightly 2-cleft or entire. Capsule greyish brown, clavate, ca. 2–2.5 cm, pubescent, 8-seeded. Seeds ovate in outline, ca. 3.5 × 3.5 mm; densely shortly hairy; hairs standing out when wetted.

Flowering and Fruiting: June to October.

Ecology and habitat: The species usually grows in the understorey of primary broad-leaved evergreen closed forest, in humid areas.

Distribution: Vietnam (Quang Binh Province, Quang Ninh District, Ba Ren farm forest); China (Yunnan), Myanmar.

Specimens examined: VIETNAM. Quang Binh Province, Quang Ninh District, 24 October 1981, D.D.Huyen 88 ( HN) ; same locality, 12 August 2008, D. V. Hai 14 ( HN) ; same locality, 22 August 1981, T. K. Lien 385 ( HN) ; same locality, 7 June 2003, N. Q. Binh & D.D.Cuong VN 1112 ( HN) .

Figures

FIGURE 1. Phlogacanthus paniculatus (T. Anderson) J.B. Imlay: A. Flowering and fruiting twig; B. Calyx and bracteoles; C. Corolla (open); D. Ovary and style; E. Fruit (Open) (Illustration drawn by Mrs Le Kim Chi, from D.V. Hai 14, HN).

FIGURE 2. Phlogacanthus paniculatus (T. Anderson) J.B. Imlay: A. Flowering and fruiting twig; B. Flower (front view); C. Calyx and flower; D. Calyx and fruit (Photos by D.V. Hai).