Mendoncia vinciflora Benoist, Bull. Mus. Hist. Nat.

Magnaghi, Emily B. & Daniel, Thomas F., 2017, Systematics of Mendoncia (Acanthaceae: Thunbergioideae) in the Paleotropics, Proceedings of the California Academy of Sciences 64 (3), pp. 37-94 : 86-87

10. Mendoncia vinciflora Benoist, Bull. Mus. Hist. Nat. (Paris) 31:387. 1925.

TYPE.— MADAGASCAR. Mahajanga: Ankaizinana [Ankaizina; 14°17ʹ51.15ʺS, 048°39ʹ56.55ʺE], Apr 1923, Decary 1955 (lectotype, designated here: P-P00091112 !) .

Young stems glabrous to mealy-glandular or sparsely to densely pubescent with antrorsely appressed, golden-brown to yellowish, unbranched, eglandular trichomes 0.1– 1.2 mm long. Leaves membranaceous to coriaceous, petioles to 40 mm long, glabrous or pubescent like young stems but with trichomes to 1.5 mm long, blades ovate to elliptic to obovate, 32–175 mm long, 19–86 mm wide, acute to rounded to subcordate at base, acute-apiculate to acuminate-caudate at apex, abaxial surface glabrous to mealy-glandular and veins (at least midvein) also pubescent with erect to flexuose, unbranched, eglandular trichomes 0. 1–2 mm long, adaxial surface glabrous to sparsely or densely pubescent with eglandular trichomes to 0.5 mm long along major veins. Inflorescences borne in leaf axils on young, mostly herbaceous and leafy stems, solitary or opposite at nodes, dichasia 1–4 per axil, peduncles to 74 mm long, glabrous or pubescent like petioles. Bracteoles color unknown, deciduous by time of fruit maturity, elliptic to ovate-elliptic, 10–18. 3 mm long, 5.6–13. 7 mm wide, rounded at base, rounded to acute at apex, abaxial surface mealy-glandular and pubescent with antrorse to antrorsely appressed, unbranched, eglandular trichomes 0.1– 1.2 mm long, adaxial surface mealy-glandular and usually not densely pubescent at apex with dense and minute trichomes. Calyx glabrous to mealy-glandular or with a few eglandular trichomes to 0.5 mm long. Corolla pink or light to dark purple, 20–35 mm long, externally mealy-glandular, internally mealy-glandular to sparsely (to more densely in throat) pubescent with glandular trichomes 0.1– 0.3 mm long, tube 9. 4–15 mm long, limb 19–37 mm in diameter, upper lip 10–17 mm long with emarginate lobes 8–13 mm long and 6. 6–14 mm wide, lower lip 9–21 mm long with emarginate lobes 5. 7–18 mm long and 6–18 mm wide. Stamens 6. 5–10 mm long, ventral pair inserted 1–2 mm distal to dorsal pair, thecae 4.2–7. 5 mm long, pubescent at base with a tuft of bristles 0.1– 0.2 mm long, these sometimes extending toward apex of thecae, connective extending 0.4– 0.5 mm beyond thecae, extension of connective attenuate, pubescent with glandular and eglandular trichomes 0.1– 0.3 mm long, staminode 0.5– 0.6 mm long. Pollen 5-colpate, E = 23–25 µm, P = 23–24 µm, P:E = 0.973–0.974, C = 5.8 µm, C: P = 0.245–0.257, rugulae sometimes ± indistinct, sparsely to densely microverrucate to microgemmate to microbaculate. Style 11–15 mm long, glabrous to sparsely mealy-glandular or sparsely pubescent with eglandular trichomes 0.2– 0.4 mm long, stigma subequally to unequally 2-lobed, lobes 0.2– 0.8 mm long. Drupe subspherical to spherical, 16. 4–30 mm long, 14. 8–25 mm in diameter, glabrous to mealy-glandular.

PHENOLOGY.— Flowering: December–April; fruiting: November–April.

DISTRIBUTION AND HABITATS.— Northern Madagascar (Antsiranana, Mahajanga; EOO = 5,756 km 2; Fig. 9 ). Plants occur in montane, wet, evergreen forests. Elev. 1240–2100 m. Mendoncia vinciflora is restricted to upper elevations in the northern mountains near the border regions of Antsiranana and Mahajanga.

ILLUSTRATIONS.— Benoist (1967: Fig. 1 ); Fig. 19 .

The lectotype of Mendoncia vinciflora is chosen from among the four collections cited in the protologue ( Benoist 1925): Decary 1955, Decary 1971, Perrier de la Bathie 15294, and Perrier de la Bathie 15324, all of which are currently extant at P.

Sometimes two staminodes are evident in the flowers of this species. Among Paleotropical species, Mendoncia vinciflora has some of the largest corollas and the largest drupes, which unlike those of other species are usually spherical.

ADDITIONAL SPECIMENS EXAMINED.— MADAGASCAR. Antsiranana: Massif de Marinorahona SW de Manambato (haute Mahavavy du nord, District Ambilobe ), [ca. 13°45ʹ24.19ʺS, 048°58ʹ52.14ʺE], Humbert & Capuron 25734 ( P) ; Camp 3, summit vegetation of Anjanaharibe-Sud, 14°44ʹ42ʺS, 049°25ʹ58ʺE, Lewis et al. 1353 ( MO) ; E of Ankaramy, Réserve Speciale Manongarivo, Antsatrotro, SE of summit, river valley between Ansatrotro and massif, 14°05ʹS, 048°23ʹE, Malcomber et al. 1489 ( MO) ; Massif de Zaratanana, Perrier de la Bathie 15294 ( P) , 15324 ( P), 15546 ( P); Andapa, Doany, forêt d’altitude d’Ambohimirahavavy , 22 km E du chef lieu de la commune Mangindrano , Bealanana , Montagne de Beampoko , 14°13ʹ41ʺS, 049°08ʹ14ʺE, Randrianarivelo et al. 330 ( MO) . Mahajanga: Ankaizeriana (Ankaizinana), [ca. 14°30ʹS, 048°55ʹE], Decary 1971 ( P) ; montagnes N de Mangindrano (haute Maevarano), jusqu’aux sommets d’Ambohimirahavavy (partage des eaux Mahavavy-Androranga : centre-nord), [ca. 14°16ʹS, 048°56ʹE], Humbert & Capuron 25016 (K, MO, P) , Humbert & Capuron 25353 ( BR, K, MO, P) ; Mangindrano, Bealanana, [ca. 14°32ʹ30ʺS, 048°45ʹE], Njila 7039 ( P) ; Fiv. Bealanana, commune Mangindrano, Forêt Antetikalambazaha , aux environ de Rivière Befosa , dans le Massif de Tsaratanana , 9 km N de Mangindrano, 14°10ʹ27ʺS, 048°56ʹ42ʺE, Razafitsalama et al. 308 ( MO) ; Ankailatsaka, (nearest village), canton de Mangindrano, District Bealanana, RN IV, Service Forestier Madagascar 47-RN ( P) .

Figures

FIGURE 9. Maps of Madagascar showing distributions of Mendoncia cowanii var. cowanii, M. cowanii var. coursii, and M. vinciflora.

FIGURE 1. Phylogenetic relationships among genera of Acanthaceae sub- family Thunbergioideae and Avicennia. OW = Old World, NW = New World. Adapted from Borg et al. (2008).

FIGURE 19. Mendoncia vinciflora. A. Fertile node with one dichasium bearing a flower (Humbert 25016). B. Corolla tube split open to show androecium (Humbert 25016). C. Apex of peduncle and flower following dehiscence of corolla, showing (from bottom) flared apex of peduncle, short pedicel, calyx, nectar disc, and gynoecium (Humbert 7039). D. Drupe (Randrianarivelo et al. 330). Drawn by Sarah Adler.