Mendoncia gilgiana (Lindau) Benoist, Bull. Soc. Bot.

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 : 74-77

6. Mendoncia gilgiana (Lindau) Benoist, Bull. Soc. Bot. France. 85:679. 1939 (“1938”).

Afromendoncia gilgiana Lindau, Bot. Jahrb. Syst. 20:1. 1894. Monachochlamys gilgiana (Lindau) S. Moore, J. Bot. 67:227, in clavi. 1929.

TYPE.— CAMEROON. Southwest: Urwald zwischen Barombi-ba-Mbu und Kake [ca. 04°37ʹ51.92ʺN, 009°23ʹ46.03ʺE], 4 Sep 1890, Preuss 481 (lectotype, designated here: K-000393683 !; isolectotypes: BM. K-00393682 !, P-00435324 !).

Mendoncia gilgiana (Lindau) Benoist var. tisserantii Benoist, Bull. Soc. Bot. France 85:679. 1939 (“1938”).

TYPE.— CENTRAL AFRICA REPUBLIC: Ouaka: région de la Oubangui , 20 km N de Bambari [ca. 05°56ʹ0.74ʺN, 020°40ʹ18.05ʺE], 10 Oct 1925, Tisserant 2055 (lectotype, designated here: P-00435316 !) .

Young stems pubescent (sometimes sparsely so) with yellowish or golden-brown, antrorse to antrorsely appressed or retrorse to retrorsely appressed, unbranched, eglandular trichomes 0.1– 1 mm long, sometimes also with minute (i.e., ˂ 0.05 mm in diameter), sessile glands and/or an overstory of flexuose to antrorse to recurved, yellowish or golden-brown, unbranched, eglandular trichomes 1.6– 2.3 mm long, trichomes of internodes soon becoming sparse. Leaves subcoriaceous, petioles to 57 mm long, pubescent like young stems, blades ovate-elliptic to elliptic, 20–116 mm long, 8–63 mm wide, rounded to truncate to subcordate at base, acute-apiculate to subacuminateto acuminate-aristulate at apex, abaxial surface sparsely pubescent with scattered, erect to flexuose to antrorse to antrorsely appressed, golden-brown, unbranched, eglandular trichomes 0.2– 1.5 mm long, trichomes sometimes concentrated on or restricted to major veins or only a few present on midrib near base of blade, adaxial surface glabrous or pubescent like abaxial surface. Inflorescences borne on young, leafy stems in axils of leaves, solitary or opposite at nodes, dichasia 1–5 per axil, peduncles to 25 mm long, sparsely pubescent like young stems. Bracteoles white to pale green (often tinged with pink or red) or purplish, mostly persistent in fruit, subcircular to elliptic to broadly ovate to lanceolate, 7. 2–23 mm long, 3. 6–16 mm wide, truncate to rounded to subcordate at base, acute to acuminate and sometimes apiculate at apex, apicule to 1 mm long, abaxial surface and margin mealy-glandular and usually pubescent (sometimes sparsely so) with an overstory of erect to flexuose trichomes similar those of overstory trichomes of young stems (except up to 3 mm long), adaxial surface glabrous to mealy-glandular. Calyx glabrous. Corolla white to purplish, 15.8–25. 5 mm long, externally glabrous, internally with cluster of sessile, glandular trichomes in throat near stamen insertion, tube 9–20. 4 mm long, limb 9–13. 1 mm in diameter, upper lip 3.5–8. 7 mm long with rounded lobes 2.8– 5.3 mm long and 2.3–4. 5 mm wide, lower lip 3.3–9. 6 mm long with rounded lobes 2.3–7. 4 mm long and 2.3–8. 4 mm wide. Stamens 3. 3–7 mm long, thecae 3. 4–5 mm long, densely pubescent at base with a tuft of bristles 0.05– 0.3 mm long and sometimes with sessile to subsessile grands dorsally, connective extending 0.4– 1.1 mm beyond thecae, extension of connective attenuate, glabrous, staminode 0.8– 1.5 mm long. Pollen 5-colpate, E = 24– 34 µm, P = 27–35 µm, P:E = 1.049–1.186, C = 5.6–8.5 µm, C: P = 0.169–0.242, rugulae microverrucate to microgemmate to microbaculate. Style 6. 5–20 mm long, glabrous or sometimes mealy-glandular near base, stigma subequally 2-lobed, lobes 0.1– 0.4 mm long. Drupe ± irregularly shaped, overall obovoid and widest at or just below apex, 6.8–11. 8 mm long, 4.8–9.0 mm in diameter (at widest diameter near apex), apically truncate to abruptly and either symmetrically or asymmetrically acute, glabrous to mealy-glandular.

PHENOLOGY.— Flowering: all year with peak flowering during July–November; fruiting: July–April.

DISTRIBUTION AND HABITATS.— Widespread throughout tropical Africa ( Cameroon, Central African Republic, Congo-Brazzaville, Congo-Kinshasa, Equatorial Guinea, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Liberia, South Sudan, Tanzania, and Uganda; EOO = 4,487,300 km 2; Fig. 14 ). Plants occur in lowland and montane, primary and secondary, moist to wet, evergreen forests; secondary bush; gallery forests; swamp forests; forest edges; roadside thickets; and in clearings. Elev. 100–1600 m.

ILLUSTRATIONS.— Lindau (1895:290, Fig. 115, D–M); Heine (1966:69, Pl. 14); Vollesen (2008:77, Fig. 12 ); Fig. 15 .

In the progologue of Mendoncia gilgiana Lindau (1894) cited two collections (Preuss 481 from Cameroon and Stuhlmann 2690 from Congo-Kinshasa). The syntypes were presumably at B and are no longer extant. A lectotype is chosen from isosyntypes at K. Duplicates of Stuhlmann 2690 were not located during our studies. The lectotype of M. gilgiana var. tisserantii is chosen from the three syntypes, all studied by us, cited in the protologue ( Benoist 1939): Tisserant 599, Tisserant 2055, and Lebrun 1613.

Bracteolar shape among specimens of Mendoncia gilgiana varies widely from subcircular to ovate-elliptic to broadly ovate to lanceolate. Pubescence is also variable in this species. For example, some collections (e.g., de Wilde 7888 and Leeuwenberg 6236, both from Cameroon) have both the overstory and understory trichomes on young stems, peduncles, and bracteoles, whereas others (e.g., Adam 29700 and 29644, both from Liberia) have only the sparse understory trichomes on young stems and peduncles and glabrous bracteoles. In Aké Assi 5424 from Ivory Coast, the young stems, peduncles, and bracteoles all bear only the understory type trichomes. Benoist (1939) distinguished M. gilgiana var. tisserantii from the nominate variety by its stems, petioles, and bracteoles being sparsely pilose. A few years later, however, he only mentioned M. gilgiana ( Benoist, 1944) . After studying this species throughout its range, this variety was not accepted as distinct by Heine (1966). Pubescence varies widely throughout the range of the species, and we concur that recognition of var. tisserantii seems unwarranted.

Ndolo Ebika 906 from Congo-Brazzaville would appear to be the first record of Mendoncia gilgiana from that nation. Plants from southern Congo-Kinshasa (Katanga: vic. Ferme Randu, ca. 09°19ʹ3.22ʺS, 022°55ʹ55.18ʺE; Fig. 14 ), known to us only from photographs by Jos Stevens ( Fig. 15 ), appear similar to M. gilgiana , but would seem to differ by the spherical ripe drupes. Because drupe shapes in the descriptions here are based on dried fruits, it is possible that the fresh fruits of M. gilgiana are or can be spherical. This occurrence, the southernmost known record of the genus in Africa, is tentatively treated as pertaining to M. gilgiana , included in the EOO, and is indicated on the map with a question mark. Collections of Mendoncia from this region are desirable to verify the identity of these plants.

ADDITIONAL SPECIMENS EXAMINED.— CAMEROON. Central: toward Nom in Ndokwanen , 19 km S of Ndikiniméki, [ca. 04°37ʹ14.27ʺN, 010°52ʹ43.92ʺ], Asonganyi 341 ( P), 373 ( P) ; 35 km SE of Yaoundé, S of village Mfoe , [ca. 03°38ʹ52.89ʺN, 011°43ʹ9.31ʺE], Breteler 1790 ( P) ; 7 km NNW of Yaoundé, village Ngoya II, [ca. 3°55ʹ34.94ʺN, 11°29ʹ14.41ʺE], Breteler 1953 (A, K, P, UC) ; Nanga-Eboko , [04°40ʹ11.88ʺN, 012°22ʹ36.05ʺE], Jacques-Felix 4756 ( P) ; Ngoro et Séréré (30 km NNE de Bafia), [ca. 04°51ʹ40.17ʺN, 011°23ʹ12.42ʺE], Letouzey 7915 (K, P) ; près N’Dokononoro , à 15 km SW de N’Dikinimeki, [04°38ʹ37.42ʺN, 010°48ʹ37.72ʺE], Letouzey 10888 (K). East: 14 km NE of Doumé, near road to Bertoua and Dimako , [ca. 04°20ʹ49.89ʺN, 013°31ʹ23.22ʺE], Breteler 767 (A, K, P) ; 43 km NW of Bertoua, along road from Mbang to Ebaka , [ca. 04°56ʹ47.05ʺN, 013°29ʹ34.52ʺE], Breteler 1383 ( P) ; Yokadouma, near Catholic mission, [ca. 03°28ʹ16.96ʺN, 015° 4ʹ27.19ʺE], Breteler 1496 ( P) ; Bertoua, 15 km along road to Deng Deng , [ca. 04°42ʹ5.11ʺN, 013°37ʹ24.93ʺ], Breteler 1834 (K, P) ; Bétaré Oya [05°35ʹ52.58ʺN, 014°04ʹ58.78ʺE], Jacques-Felix 4574 ( P) ; Dengdeng, [05°11ʹ46.87ʺN, 013°31ʹ33.11ʺE], Jacques-Felix 4666 ( P), 4667 ( P) ; 12 km N of Ndemba II = 32 km N of KM 29 of road Bertoua–Nanga Ebbko, [ca. 04°46ʹ57.92ʺN, 013°22ʹ9.68ʺE], J. Leeuwenberg 5960 (K, MO) ; near Momjépom, KM 21 of road Yokadouma-Moloundou, [ca. 03°21ʹ59.02ʺN, 014°59ʹ22.70ʺE], Leeuwenberg 6236 (K, MO, P) ; Bangue ( KM 75 route Yokadouma – Moloundou), [02°55ʹ44.46ʺN, 015°14ʹ46.21ʺ], Letouzey 5112 (K, P) ; près Yabenot II, 30 km SSE de Ngoila ( Axe Lomie-Souanke ), [ca. 02°24ʹ32.18ʺN, 014°04ʹ59.27ʺE], Letouzey 12006 ( P). Littoral: Ebone, Nkongsamba–Douala , KM 114 , 004 °52ʹN, 009°54ʹE, Bamps 1517 (K, P) ; Ebo Forest Research Station (proposed Natl. Park ), New Masseng trail, J. Osborne et al. 166 (K). South: around Zoetele , 52 km SE Mbalmayo, [ca. 03°14ʹ40.49ʺN, 011°51ʹ55.62ʺE], Asonganyi 125 ( P) ; Station du Cacaoyer de N’Koemvone , 02°49ʹN, 011°08ʹE, de Wilde 7519 ( MO) ; hill roughly between N’Kolandom and N’Koemvone , 02°49ʹN, 011°09ʹE, de Wilde 7888 (K, MO, P) ; Dept. Dja et Lobo, Nkolembembe , 60 km SE of Akonolinga, 3°15ʹN, 012°31ʹE, Dongmo & Nkongmeneck 553 ( MO) ; près Aveubé (25 km ENE de D’joum), [ca. 02°40ʹ49.80ʺN, 012°54ʹ13.83ʺE], Letouzey 8283 (K, P) ; Meyo–Nyaka (9 km SSE Ambam), [ca. 02°18ʹ53.94ʺN, 011°17ʹ59.97ʺE], Raynal & Raynal 10106 ( P). Southwest: vicinity of Nyasoso , Cable et al. 2882 (K), 3246 (K) ; Kupe village, hunter’s path from Kupe village to mountain top, running to S and parallel with Esense river , 04°47ʹN, 009°41ʹE, Cheek 7092 (K) ; Nyasoso, Mount Kupe, Walter’s Trail , 04°50ʹN, 009°42ʹE, Cheek 7487 (F, K, P) ; Mt. Kupe, Nyasoso, Max’s trail to top of mountain, 04°49ʹN, 009°42ʹE, Cheek & Ebwekoh 5660 (K) ; Division Kupe-Muanenguba, Muambong , 04°58ʹN, 009°46ʹE, Cheek et al. 9366 (K) ; Mt. Kupe, Gazette-Nyasoso, Nyasoso– Bedume road, God-dat trail (opposite Ngusi road), 04°52ʹN, 009°41ʹE, Etuge M. et al. 2515 (K, MO) ; Mount Kupe, Schoenenberger 1 (K) ; Mount Kupe, SW slope, main trail to the top from Kupe village , 04°45ʹN, 009°41ʹE, Schoenenberger 51 (F, K, P) ; Division Kupe-Muanenguba, above Nyasoso on Mann’s trail up Mt. Kupe , Sidwell et al. 384 (K) ; Korup Natl. Park between Ikenge and Esukutang , ca. 6 km W of Ikenge, ca. 05°17ʹN, 009°05ʹE, Thomas et al. 7603 ( MO) ; Bakossi Mts. , W of Bangem, 05°05ʹN, 009°42ʹE, Thomas & Mcleod 5280 ( MO). Province not determined: Samnat ( Dikel ), et Messimni (confluent Mékié-Djérem), Letouzey 3602 ( P). CENTRAL AFRICAN REPUBLIC. Lobaye: bord de la Lobé, 5 km NW de Boubatiki , [ca. 03°59ʹ54.21ʺN, 017°49ʹ38.56ʺE], Badré 55 (K, P) ; région de Mbaiki et Boukoko , [ca. 03°52ʹ30.12ʺN, 017°57ʹ30.75ʺE], Tisserant 118 ( P). Ouaka: région de Bambari, Riv. Gbatemoze , 15 km NW de Bambari, [ca. 05°58ʹ22.61ʺN, 020°36ʹ23.67ʺE], Tisserant 599 ( P) ; galerie Ruiss. aff. Yamwé , 20 km N Bambari, [ca. 05°59ʹ55.98ʺN, 020°33ʹ34.63ʺE], Tisserant 2055 ( P). Sangha-Mbare: 45 km S of Lidjombo, E side of Sangha River , Ndakan study area, 02°21ʹN, 016°09ʹE, Harris 2576 (K, MO) ; Dzangha camp, 11 km NE of Bayanga, 02°57ʹ N, 016°21ʹ E, Harris 3523 (E-photo) ; 2 km W of Kongana camp, 02°47ʹN, 016°25ʹE, Harris 4070 (E-photo). CONGO-BRAZZAVILLE. Sangha: Bomassa, 02°12ʹ38ʺN, 016°11ʹ38ʺE, Ndolo Ebika 906 (E-photo). CONGO-KINSHASA. Equator: Sud-Ubangi, Libenge-Ubangi, [ca. 03°36ʹ57.63ʺN, 018°37ʹ59.24ʺE], Lebrun 1613 (F, P). North-Kivu: Manyema, Mutongo , Terr. Walikale , [01°21ʹ00.61ʺS, 028°05ʹ42.06ʺE], Gutzwiller 3314 (K, MO). Orientale: Bambesa , [ca. 03°26ʹ31.83ʺN, 025°41ʹ8.31ʺE], Blomme 143 (K) ; Yaliboto vers Yalibonga ( Bengamisa ), Yanonge , [ca. 00°34ʹ08.45ʺN, 24°42ʹ54.02ʺE], Bolangi Bo’yanguma 64 ( P) ; Ituri Distr., Mongbwalu , N of Msisi village, 01°59.56ʹN, 030°00.29ʹE, Bytebier et al. 3293 (K) ; Bas-Uele, Dewulf 135 ( CAS) ; terr. Monkoto, Iwama , [ca. 02°08ʹ38.46ʺS, 021°34ʹ01.12ʺE], Evrard 2830 (K) ; terr. Befale, Kikako , [ca. 00°16ʹ20.68ʺN, 020°58ʹ31.99ʺE], Evrard 3055 (K) ; Bambesa , [03°27ʹ33.85ʺN, 25°42ʹ09.68ʺE], Gerard 3286 (K), 4567 ( MO) ; Irumu–Beni , KM 100 , 01 °27ʹN, 29°52ʹE], Gille 261 (F, P) ; Wamba–Uele , [ca. 02°08ʹ01.69ʺN, 28°00ʹ43.19ʺE], Lebrun 3281 ( P) ; Haut-Zaire , 12 km E de Wanie-Rukula, [00°12ʹ04.18ʺN, 25°35ʹ40.19ʺE], Lisowski 15616 (K), 16153 (K) ; Ituri, Mont Hoyo , bord de la route forestiere menant vers le Poste Hoyo, [ca. 01°13ʹ05.37ʺN, 29°48ʹ48.74ʺE], Lisowski 41144 (K) ; Yangambi , KM 6 route de Ngazi, Louis 517 ( FHO) ; Yalibwa, en Yangambi , [ca. 00°54ʹ20.78ʺN, 024°28ʹ53.65ʺE], Louis 1350 ( CAS) ; Yangambi , reserve division cafeiers, Louis 5700 (K, P) ; Yangambi, [ca. 00°48ʹ40.29ʺN, 024°32ʹ19.70ʺE], Louis 7622 (K, MO-photo, P) ; Yambuya [ca. 01°15ʹ45.47ʺN, 24°33ʹ13.83ʺE], Louis 7735 (K, P). South-Kivu: Panzi , galerie de la Makita, Callens 3436 (K) ; Terr. Kalehe, près vill. Makwe, KM 105 route Kavumu–Walikale , [01°56ʹ6.98ʺS, 028°27ʹ57.96ʺE], Christiaensen 1847 ( MO) ; Muhaki Terr. Shabunda , [ca. 02°43ʹ29.14ʺS, 027°20ʹ54.96ʺE], Leonard 3937 ( CAS). Province not determined: Semlike , Kassner 3102 ( P). EQUATORIAL GUINEA. Bioko Sur: between Musola and Concepción , [ca. 03°24ʹ48.92ʺN, 008°41ʹ49.84ʺE], Wrigley & Melville 549 (K). Centro Sur: KM 90–91 , Bata–Niefang–Monte Alen, proximo a Niefang–Evinayong , [ca. 01°34ʹ27.22ʺN, 010°22ʹ25.58ʺE], Carvalho 5376 ( MO). GABON. Ogooue-Ivindo: Mekambo , [ca. 01°00ʹ34.82ʺN, 013°57ʹ07.65ʺE], Hallé 2595 ( P). GHANA. Eastern: Atewa Range F.R., [ca. 06°08ʹ31.24ʺN, 00°36ʹ26.58ʺW], Hall & Enti 39461 (K). GUINEA. Macenta: Mts. Ziama, path from Sérédou to large antenna on Mt. Papo , [08°22ʹ32.30ʺN, 009°19ʹ34.63ʺW], Burgt 1290 (K). IVORY COAST. Dix-Huit Montagnes: entre Danané et N’Zo, [07°07ʹ30ʺN, 007°46ʹ17ʺW], Aké Assi 5424 (G) ; Nimpleu , près du Mont Momy [07°27ʹ4.12ʺN, 008°04ʹ43.59ʺW], Aké Assi 7047 ( P). District not determined: frontière Guinèe-Côte d’Ivoire, Nozerau s.n. ( P). KENYA. Vihiga: Yala River Forest, side opposite Nature Reserve, near Quarry Hill , [ca. 00° 00ʹ11.40.67ʺN, 034°52ʹ58.04ʺE], Gilbert 6886 (K). LIBERIA. Lofa: Nekabozu District, Voinjama , [ca. 08°22ʹ21.21ʺN, 009°44ʹ14.46ʺW], Baldwin 9971 (K). Nimba: Yéképa, forêt frontière Guinée , [ca. 07°34ʹ08.39ʺN, 08°30ʹ40.52ʺW], Adam 29644 ( MO) ; Yéképa, Gangra Road , Adam 29700 ( MO). SOUTH SUDAN. Eastern Equatoria: Talanga, Imatong Mountains , 04°01ʹN, 32°45ʹE, Friis & Vollesen 494 (K). TANZANIA. Kagera: Bukoba Distr., Minziro Forest Reserve , 01°05ʹS, 031°32ʹE, Bidgood et al. 4858 ( CAS, K) ; Bukoba Rural Distr., Minziro Village, Nyakabanga , near Kagera River , 01°03ʹ09ʺS, 031°35ʹ59ʺE, Festo et al. 266 (K, MO) ; Bukoba Rural Distr., Minziro Forest Reserve, SW of Minziri village toward Mtukula , 01°02ʹ33ʺS, 031°29ʹ47ʺE, Festo et al. 1292 (K, MO) ; Bukoba Rural Distr., Minziro Forest Reserve , 01°01ʹ06ʺS, 031°37ʹ06ʺE, Simon & Bayona 364 (K, MO). UGANDA. Central: Entebbe , [ca. 00°05ʹ59.73ʺN, 032°28ʹ07.20ʺE], Brown 314 (K) ; Wakiso Distr., Kajansi Forest, mile 10 Entebbe Rd. , [ca. 00°12ʹ13.91ʺN, 032°33ʹ02.57ʺE], Chandler 1898 (K, P) ; Mengo Distr., ca. 5 mi SW of Mpigi, Mpanga Forest Reserve , [ca. 00°12ʹ16.93ʺN, 032°18ʹ30.07ʺE], Drummond & Hemsley 4745 (K). Eastern: Bugisu Distr., Namatale L.F.R., [ca. 01°06ʹ14.69ʺN, 034°25ʹ07.00ʺE], Philip 927 (K) ; Western: Busingiro, Budongo , Harris 143 (K) ; Bulisa Distr., Budongo Forest, [ca. 01°47ʹ36.98ʺN, 031°35ʹ38.77ʺE], Loveridge 106 (A, K, MO-photo) ; Masindi Distr., Siba Forest , [ca. 01°41ʹ49.74ʺN, 31°27ʹ12.42ʺE], Sangster 15 (K) ; Bunyoro Distr., Bujenje Co., Budongo Forest , [ca. 0147ʹ 46.52ʺN, 031°34ʹ55.61ʺE], Synnott 601 (K). Region not determined: Forest ( Makia ?), Mubango?, Drummer 5586 (K) ; without locality, Scott 7331 (K).

Figures

FIGURE 14. Map of central Africa showing distribution of Mendoncia gilgiana (see text for explanation of question mark).

FIGURE 12. Map of Madagascar showing distributions of Mendoncia decaryi and M. delphina, and map of Madagascar and Mayotte showing distribution of M. flagellaris.

FIGURE 15. Mendoncia gilgiana. A. Node of young stem with open flower on one dichasium and greenish bracteoles. B. Flower and pinkish purple bracteoles. C. Mature drupes and spreading and deciduous bracteoles. (Photos by Jos Stevens from southeastern Congo-Kinshasa; African Plants-A Photo Guide: www.africanplants.senckenberg.de; non-commercial scientific and educational use; see text for additional information).