Argyreia mastersii (Prain) Raizada, Indian Forester

P. R., Lawand & Shimpale, V. B., 2024, Revision of the genus Argyreia (Convolvulaceae) from India, Rheedea 34 (5), pp. 337-396 : 370-371

21. Argyreia mastersii (Prain) Raizada, Indian Forester 93: 754. 1967. Lettsomia mastersii Prain, J. Asiat.

Soc. Bengal, Pt. 2, Nat. Hist. 63: 98. 1894. Lectotype

(designated by Shalini et al., 2017: 173): INDIA, Assam, Naga Hills, s.d., Masters 255 (CAL [CAL0000018546!];

Isolecto CAL [CAL0000018544!, CAL0000018541!,

CAL0000018542!, CAL0000018543!, CAL0000025898!,

CAL0000025899!]; K [K000197305 digital image!],

P [P00584827 digital image!]; K [K000197304 digital image!]), Fig. 9a–e

Semi-woody perennial climber; older stems woody, glabrous while the younger stem brown rusty hirsute, terete. Leaf lamina ovate to widely ovate, 9–19 × 8–15 cm, base truncate to shallowly cordate, apex acute, secondary veins 8–10 pairs raised beneath, hirsute above, brown sericeous below; petiole hirsute as stem, 7–12 cm long, longer than the peduncle. Inflorescence axillary, dichotomous cyme, 9–15-flowered; peduncle brown rusty hirsute, 1.5–3 cm long, shorter than the petiole. Flowers subsessile; pedicel c. 5 mm long, bracteate; bracts 2, unequal, persistent, one large, 2.5–3.0 cm, second c. 2.5 cm, green, hirsute outer, glabrous inner, linear. Sepals 5, unequal, hairy outer, glabrous inside, outer two large, 1.0– 1.3 cm long, ovate, apex acuminate, inner three small, 0.6–1 cm long, ovate, apex acute, hairy except on overlapped parts. Corolla campanulate, 3–4.5 cm long, c. 3 cm across, throat c. 1.5 cm wide, white inside and outer, limbs purple, hairy on midpetaline bands. Stamens 5, up to middle of corolla throat, equal 1.2–1.4 cm long; filaments white, dilated and glandular hairy at base; anthers 4–5 mm long, off white. Ovary glabrous, white in color; style single, equalling stamen height; stigma biglobose, white, papillate. Berries globose, 0.7–1 cm across, dark red–purple enclosed with persistent calyx, 2–4-seeded; seeds trigonous, brown in color.

Flowering & Fruiting: Flowering from September to October and fruiting from late October to December.

Habitat: Grows on trees along evergreen forest outskirts.

Etymology: The species is named after its field collector Mr. Masters.

Distribution: India (Mizoram), China, Myanmar and Thailand.

Specimens examined: INDIA, Mizoram, Mamit District, West Phaileng, Dampa Tiger Reserve,

30.10.2007, B.K. Sinha 117224 (ASSAM) [filed as Argyreia roxburghii ]; Mamit District, Teirei,

09.10.2018, P. R. Lawand 017 ( NCK); Aizawl, West

Phaileng, Damparengpui, November 2017, P. R .

Lawand 052 (NCK).

Notes:The species shares morphological similarities with the Thai species, Argyreia ionantha (Kerr) Khunwasi & Traiperm in leaf size, shape and general bract shape. However, it significantly differs in having linear bracts, acuminate subequal sepals, campanulate purple-white corolla, and stamens of equal length.

Figures

Fig.9. Argyreia maSterSii (Prain) Raizada (a-e): a. Habit;b. A cut flower withstamens and stigma;c. Bracts;d. Sepals;e. Infrutescence. Argyreia mOlliS (Burm.f.) Choisy (f-i): f. Habit;g. Inflorescence;h. Leaf abaxial surface;i. Sepals.Argyreia nellygherya Choisy (j-m): j. Fruiting twig;k. Flowering twig; l. Bracts;m. Sepals.