Mendoncia lindaviana (Gilg ex Lindau) Benoist, Mem. Soc. Linn.

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 : 81-83

8. Mendoncia lindaviana (Gilg ex Lindau) Benoist, Mem. Soc. Linn. Normandie, n.s.i. 2:44. 1928.

Afromendoncia lindaviana Gilg ex Lindau Bot. Jahrb. Syst. 17:112. 1893. Monachochlamys lindaviana (Gilg ex Lindau) S. Moore J. Bot. 67:226, in clavi. 1929.

TYPE.— GABON. Estuaire: Sibange-Farm on the Gaboon, Dec 1880, Soyaux 156 (lectotype, designated here: K-000393685 !).

Lirayea floribunda Pierre, Bull. Mus. Hist. Nat. (Paris) 2:342. 1896. Afromendoncia floribunda (Pierre) Burkill, Fl. Trop. Afr. 5:6. 1899. Monachochlamys floribunda (Pierre) S. Moore, J. Bot. 67:226, in clavi. 1929. Mendoncia floribunda (Pierre) Benoist, Notul. Syst. (Paris) 11:143. 1944.

TYPE.— GABON. Estuaire: prope Libreville, [ca. 00°27ʹ44.20ʺN, 009°28ʹ34.84ʺE], 1891, Jolly 101 holotype: P-00435322 !).

Afromendoncia klaineana Pierre ex Benoist, Notul. Syst. (Paris) 2:285. 1912, nomen nud.

Young stems glabrous to mealy-glandular, lacking elongate trichomes. Leaves coriaceous, petioles to 25 mm long, glabrous to mealy-glandular (rarely with antrorse, eglandular, unbranched trichomes to 2 mm long), blades ovate-elliptic to elliptic to lanceolate, 34–189 mm long, 11–80 mm wide, acute at base, (acute-apiculate to) subacuminate-aristate at apex, surfaces glabrous. Inflorescences (see discussion below) mostly borne on woody, peg-like short-shoots 2–10 mm long at leafless nodes of older, woody stems, short-shoots solitary or opposite at nodes, sometimes branched (branches appearing ± clustered or dendritic) in an axil and then to 20 mm long, dichasia 1–20 or more per axil at a time (but with peduncular scars on branched short-shoots revealing 100 or more dichasia present over time), peduncles purplish, to 42 mm long, glabrous. Bracteoles white to greenish white (often tinged with pink or purple) or pinkish or purplish, persistent as fruit matures and usually deciduous by maturity, ovate-elliptic to elliptic to subcircular to obovate, 6.6–16. 7 mm long, 4. 4–10 mm wide, acute- to acuminate-apiculate at apex, apicule 0.1– 1.5 mm long, truncate to rounded at base, abaxial surface mealy-glandular (lacking elongate trichomes), adaxial surface mealy-glandular. Calyx mealy-glandular (sometimes mostly or exclusively so on or near marginal rim). Corolla white (sometimes pinkish at base), 13. 5–24 mm long, externally ± mealy-glandular, internally mealy-glandular (especially on adaxial surface of lobes), tube 8.5–16. 4 mm long, limb 7.2–18. 3 mm in diameter, upper lip 2.8– 8.4 mm long with rounded lobes 2.8– 6.3 mm long and 2.2–6. 5 mm wide, lower lip 5.7–11. 2 mm long with lobes 2.9– 7 mm long and 3. 1–9 mm wide. Stamens 4.1–6. 5 mm long, ventral pair inserted 1.2– 1.6 mm distal to dorsal pair, thecae 2.2–4. 6 mm long, pubescent at base with a tuft of bristles 0.1– 0.2 mm long, these sometimes becoming sparse and extending toward apex, and also beset with mostly sessile glands on either dorsal or ventral surface, connective extending 0.2– 0.5 mm beyond thecae, connective extension attenuate, sometimes with a cluster of sessile glands on dorsal surface at apex, staminode not seen. Pollen 6-colpate, E = 36 µm, P = 35 µm, P:E = 0.980, C = 7.8–8.2 µm; C: P = 0.223–0.236, rugulae sparsely microverrucate to microgemmate. Style 11. 6–14 mm long, glabrous, stigma subequally to unequally 2-lobed, lobes 0.1– 0.4 mm long. Drupe oblong, laterally compressed, 12.3–19. 9 mm long, 6.5–14. 5 mm in diameter, glabrous to ± mealy-glandular.

PHENOLOGY.— Flowering: August–June; fruiting: all year.

DISTRIBUTION AND HABITATS.— Tropical central Africa ( Cameroon, Central African Republic, Congo-Brazzaville, Congo-Kinshasa, Gabon; EOO = 1,586,281 km 2; Fig. 7 ). Plants occur in lowland to montane, primary and secondary, wet, evergreen forests; semi-deciduous forests; swamp forests; gallery forests; and clearings. Elev. 60–1000 m. Mendoncia lindaviana also likely occurs in the continental portion of Equatorial Guinea, which lies between known occurrences in Cameroon and Gabon, but has no specimens have been seen from there.

ILLUSTRATIONS.— Thiselton-Dyer (1896:t. 2426); Heine (1966:67, Pl. 13); Fig. 17.

LOCAL NAME.— “Amokisemekiseme” (Kibila; Madidi 332).

Heine (1966) indicated that the holotype of Afromendoncia lindaviana was destroyed at B, and that there was an isotype at P. We were unable to locate the isotype at P, but there is another one at K, which we designate as the lectotype for this name.

A mature inflorescence bearing a branched short-shoot in Mendoncia lindaviana , as described above, is shown in Figures 3F , 17D . Rarely, dichasia are borne on younger shoots with leaves present at the nodes (e.g., Breteler & Jongkind 10386, Madidi 332). In these younger inflorescences, the short-shoots are present but only two to three mm long. Such plants are recognizable as pertaining to M. lindaviana by their lack of trichomes on stems, leaf blades, and peduncles; the usually aristate leaf apices ( Fig. 3B ); and the consistently oblong drupes ( Fig. 3D ).

ADDITIONAL SPECIMENS EXAMINED.— CAMEROON. Central: Dja et Lobo , Koungoulou , 72 km SW of Akonolinga, Nkongmeneck 1478 (K) . East: Doumé, near Catholic mission, [ca. 04°14ʹ34.60ʺN, 013°27ʹ57.10ʺE], Breteler 1858 (K, P) ; 27 km SW of Bertoua near Toungrélo village, Breteler 2620 (K, P) ; Nkoue–Bertoua, Letouzey 3051 ( P) ; Ngondouma–Bertoua, Letouzey 3102 ( P) ; près des vallées du Dja et de l’Edjune–Abong-Mbang , [ca. 03°28ʹ19.13ʺN, 013°22ʹ41.29ʺE], Letouzey 3806 (K, P) ; piste forestière Anpel-Mase–Abong-Mbang, Letouzey 3994 (K, P) ; Matcheboum [04°06ʹ39.58ʺN, 013°14ʹ26.80ʺE] près Abong-Mbang, Letouzey 4605 (K, P) . South: colline Ongongo près Mbanga (km 81 route Kribi–Ebolowa , près Sous-préfecture Akom II) , Nyabessan, Letouzey 9484 ( CAS, K, P) ; Bipinde [ca. 03°04ʹ43.43ʺN, 010°24ʹ58.48ʺE], Zenker 194 ( GH) , 965 (K, P), 1801 ( P), s.n. ( P). CENTRAL AFRICAN REPUBLIC. Sangha-Mbare: Kongana , 25 km SE of Bayanga, 02°47ʹN, 016°25ʹE, Harris 5029 (E-photo). CONGO-BRAZZAVILLE . Kouilou: Mayombe, near Niari River , 04°02ʹ24.7ʺS, 012°09ʹ52.4ʺE, M’Boungou et al. MR 421 ( MO) ; route Pounga–Dimonika, source “ Paris Sangha ,” Cusset 568 ( P) ; environs de Dimonika, entre Tour Meteo et piste Kuilila–Makaba [ca. 04°08ʹ3.44ʺS, 012°21ʹ4.06ʺE], Cusset 1193 ( P) ; environs de Dimonika: versant E du Bamba, au-dessus de la Loubomo, Cusset 1227 ( P) ; Dimonika, Moutsamboté 139 ( P) . Lékoumou: Mont Ndoumou, au niveau de village de Mandili , [ca. 03°22ʹ9.19ʺS, 013°39ʹ48.90ʺE], Bouquet 1788 ( P) . Department not determined: Mayombe, Hallé 1523 ( P) . CONGO-KINSHASA. Equator: Station Inéac Boketa, Riviere Wolo , [ca. 03°10ʹ11.05ʺN, 19°48ʹ01.59ʺE], Evrard 1027 ( BR) ; Bomputu ( Boende ), [ca. 00°18ʹ51.74ʺS, 020°31ʹ10.59ʺE], Evrard 3977 ( BR, K) ; Befale–Tolongote , [ca. 00°33ʹ56.88ʺN, 020°45ʹ18.57ʺE], Evrard 4163 ( BR) . Orientale: Bambesa , [03°27ʹ33.85ʺN, 25°42ʹ09.68ʺE], Gerard 5537 (K) ; Terr. Isangi, Yabohondo , [ca. 00°44ʹ22.47ʺN, 023°58ʹ35.27ʺE], Germain 8757 (K) ; Zone de Mambasa (Ituri), Epulu , 01°25ʹN, 028°35ʹE, Hart 727 ( BR, F) , 925 ( BR, F); Zone de Mambasa (Ituri Forest), Lenda [01°24ʹN, 028°34ʹE], Kahimdo 87 (K, MO) ; Buta , [02°50ʹ22.62ʺN, 024°44ʹ9.04ʺE], Lebrun 2539 ( CAS) ; environs de Kisangani, le Kongole sur la Lindi , [ca. 00°34ʹ11.07ʺN, 025° 07ʹ57.16ʺE], Lisowski 52254 (K) ; Jambao , a 25 km au NW de Jangambi, [ca. 0°54ʹ40.16ʺN, 24°21ʹ16.10ʺE], Louis 8974 ( MO, P) ; Lèlanda W de Janojambi, [ca, 00°47ʹ58.47ʺN, 024°22ʹ57.64ʺE], Louis 10825 (K) ; Territoire Mambasa (Ituri Forest), Lenda , 01°24ʹN, 28°34ʹE, Madidi 332 (K, MO) . North-Kivu: Territory Kalehe, route Kavumu–Walikale , Trougi , [ca. 01°51ʹ57.98ʺS, 028°29ʹ54.26ʺE], Troupin 2502 (K) . South-Kivu: Tubalaka, Tsunyakini / Bunyakiri , Terr. Kalihe , [ca. 02°05ʹ30.37ʺS, 028°34ʹ36.47ʺE], Gutzwiller 1398 ( BR) . GABON. Estuaire: Akoga, Mts. de Cristal, Hallé 878 ( P) ; Libreville, Klaine 700 ( CAS, P) ; 22 km Kougeleu – Asak , [ca. 00°26ʹ5.99ʺN, 010°02ʹ20.70ʺE], Leeuwenberg & Persoon 13599 (K, MO, P) ; about 7 km E. of M’Voum, 24 km NE of Ntoum, 0°33ʹN, 009°52ʹE, Louis et al. 275 ( MO) ; River Muni, Corisco Bay, Mann 1849 (K, P) ; Monts de Cristal: Tchimbélé Dam region, 00°37ʹN, 010°24ʹE, McPherson 17918 ( MO) . Moyen-Ogooué: Missanga , 5-15 km NW of Ndjolé, 00°05ʹS, 101°45ʹE, Breteler & Jongkind 10386 ( CAS, G) . Ngounié: between Mouila and Yeno, about 34 km on road from Mouila, 01°45ʹS, 011°20ʹE, Breteler et al. 8106 (K, MO, P) ; old forest along Waka river, about 1–2 km SW of Forestry exploitation Camp Waka situated about 32 km SW of Sindara (by road 65km), 01°14ʹS, 010°53ʹE, Louis et al. 1368 ( MO) ; “Haute Ngounyé,” Le Tetsu 5497 ( P) ; 60 km on road Mouila to Yeno, 01°41.91ʹS, 011°24.09ʹE, Wieringa et al. 4552 (K) . Nyaga: région du Nyanga; Manzembi, [ca. -3.146086455, 10.91076607], Le Tetsu 2104 (G, P) . Ogooué-Ivindo: Belinga, Mines de Fer , [ca. 01°08ʹ7.92ʺN, 13°12ʹ07.74ʺE], Aubreville et al. 20 ( P) ; Belinga, about 2 km. along the lower track of Babiel Nord, Breteler & de Wilde 723 ( MO, P) ; Station I.R.E. T. (M’Passa Field Station), 10 km S de Makokou sur la rivière Ivindo [00°30ʹ38.58ʺN, 012°48ʹ15.73ʺE], Dorr & Barnett 4241 (K, MO) ; Station d’Ipassa , 10 km S de Makokou, Florence 812 ( P) ; M’Passa Field Station, near Makokou on Riviere l’Ivindo, transect 17, Gentry 33450 ( MO) ; Makokou , [00°33ʹ35.78ʺN, 12°53ʹ17.72ʺE], Hallé 1078 ( P) ; 6 km NE de Mékambo , [ca. 01°01ʹ12.92ʺN, 013°59ʹ28.88ʺE], Hallé 2599 (K, P) ; 15 km SW Makokou, CNRS Mission Biologique , [ca. 00°27ʹ51.58ʺN, 012°45ʹ33.04ʺE], Hallé 2655 (K, P) ; Belinga, Hallé 3005 ( P) , 3041 ( P), 3240 ( P), 3393 ( P); Ipessa, 10 km S de Makokou, Layon J vers 620, Hladik 2485 ( P) ; Ipessa, Makokou, Hladik s.n. ( P) . Ogooue-Lolo: région de Lastoursville , [ca. 00°49ʹ58.95ʺS, 012°40ʹ21.68ʺ], Le Tetsu 7675 ( P) . Woleu-Ntem: about 22 km NE of Asok , [ca. 00°51ʹ2.58ʺN, 010°27ʹ48.27ʺE], Breteler & de Wilde 234 ( MO) . Province not determined: région entre Ogooué et Cameroun, Bengò, Le Tetsu 9117 ( P) ; Ogoué (river), Leroy s.n. ( P) . COUNTRY UNDETERMINED. Without locale: Hladik 1396 ( P) ; “ Nèuga ,” Lana 191 ( BR) .

Figures

FIGURE 7. Map of central Africa showing distributions of Mendoncia combretoides and M. lindaviana.

FIGURE 17. Mendoncia lindaviana. A. Older, woody shoot bearing dichasia with flowers and fruits at nodes. B. Flower. C. Dichasium with flower in background (showing relationship between style/stigma and anthers) and dichasium with corolla dehisced in foreground (showing 2-lobed stigma). D. Node of woody shoot showing dichasia borne on peg-like stubs and bearing young fruits. (A, C, photos by Xander van der Burgt of M’Boungou et al. MR 421 from Congo-Brazzaville, used with permission; B, photo by Benedict John Pollard from Congo-Brazzaville, used with permission; D, photo and copyright by Ehoarn Bidault of Bidault 900bis from Gabon, on Tropicos [www.tropicos.org/Image/100228305], CC by- NC-ND 3.0).

FIGURE 3. Morphological features of Mendoncia spp. A. Abaxial leaf surface of M. cowanii var. coursii (Rakotonandrasana 485). B. Abaxial leaf surface of M. lindaviana (Vermoesen 191). C. Dichasium of M. cowanii var. coursii (Rakotonandrasana 485) with one bracteole removed showing single flower with densely pubescent calyx. D. Oblong drupe of M. lindaviana (Louis et al. 275). E. Cross-section through dried drupe of M. vinciflora (Lewis et al. 1353) showing bony seed with embryo. F. Node of older shoot of M. lindaviana (Breteler et al. 8106) with dichasia borne on branched and woody short-shoots.