A revision of Xylopia L. (Annonaceae): the species of Tropical Africa Author Johnson, David M. Department of Botany-Microbiology, Ohio Wesleyan University, Delaware, OH, 43015, USA Author Murray, Nancy A. Department of Botany-Microbiology, Ohio Wesleyan University, Delaware, OH, 43015, USA namurray@owu.edu text PhytoKeys 2018 2018-04-24 97 1 252 http://dx.doi.org/10.3897/phytokeys.97.20975 journal article http://dx.doi.org/10.3897/phytokeys.97.20975 1314-2003-97-1 BD026E15CD67FF99E01FF605FFF6FFEF 1239255 3. Xylopia rubescens Oliver, Fl. trop. Afr. 1: 30. 1868. Fig. 11 Xylopicrum rubescens (Oliver) Kuntze, Revis. gen. pl. 1: 8. 1891. Type. NIGERIA ["Upper Guinea"]. Rivers, Old Calabar, s. d., W. C. Thomson 53 (holotype: K! [000199073]). Xylopia klaineana Pierre ex Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 59-60. 1901. Xylopia rubescens Oliver var. klaineana (Engler & Diels) Pellegrin, Bull. Soc. Bot. France, Mem . 31: 70. 1949. Type. GABON. Without definite locality, Oct 1898, T.-J. Klaine 1327 (holotype: P! [00169139]; isotypes: B! [100154150], P! [00169138]). Xylopia humilis Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 60 + t. 21B, a-f. 1901. Type. LIBERIA [ "Oberguinea" ]. Grand Bassa County, Fishtown bei Granbassa, 27 Aug 1898, M. Dinklage 2006 (lectotype, here designated: B! [10 0154147]; isotypes: A! [00061927, 00062417], B! [100154145, 100154146, 1001541480], K! [000199074, 000199075, 000199076]). Xylopia batesii Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 62. 1901. Type. CAMEROON or GABON. Angom, 70 engl. Meilen oestlich von Gabun, Oct 1896 [29 Oct 1897 on P sheet], G. L. Bates 561 (holotype: K! [000199058]; isotypes: BM! [000510769], G! [00190711], P! [00169131, 00169132]). Xylopia butayei De Wildeman, Ann. Mus. Congo, Ser . 4, Bot. 1: 33. 1902. Type. DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central, Malela (Bas-Congo), R. P. Butaye, coll. J. Gillet 2239 (holotype: BR!; isotype: BR! [0000008825391]). Xylopia zenkeri Engler & Diels, Bot. Jahrb. Syst. 39: 480. 1907. Type. CAMEROON. South Province, bei Bipindi unweit Mimfia im Urwald, Mar 1904, G. A. Zenker 2827 (holotype B! [100154149]; isotypes: BM! [000511041], G! [00190712, 00190713], GOET! [005735], HBG! [502474], K! [000199060], L! [0196246], M! [0107919], P! S! [07-13458], WAG! [0065882], WU! [0025792]). Xylopia gossweileri Exell, J. Bot. 64: Suppl. 6. 1926. Type. ANGOLA ["Portuguese Congo"]. Cabinda Province, Cabinda, Pango Munga, Mayumbe, s. d., J. Gossweiler 6222 (holotype: BM! [000511046], photos at GH, MO, NY). Description. Tree up to 25 m tall, d.b.h. up to 70 cm, rarely described as a shrub or liana, bole straight, cylindrical, usually with stilt roots arising from the trunk up to a height of 2 m, short secondary branches forming a narrow crown; bark white, pale yellowish brown, or light gray, smooth. Twigs brown to gray, eventually whitish gray, initially appressed golden-pubescent, the hairs 0.2-0.5 mm long, but soon glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 7.3-21.3 cm long, 3.6-8.4 cm wide, subcoriaceous, occasionally chartaceous, strongly discolorous, olive-green adaxially, rusty or orange-brown abaxially, rarely concolorous, oblong, elliptic, or oblanceolate, apex short-acuminate or cuspidate, the acumen or cusp 2-15 mm long, occasionally acute or rounded, base cuneate to occasionally rounded and decurrent on petiole, glabrous adaxially, finely appressed-pubescent abaxially, rarely glabrous; midrib impressed to plane adaxially, raised and usually formed into a sharp keel distal to the midpoint abaxially, secondary veins weakly brochidodromous, 8-16 per side, diverging at 45-70° from the midrib, slightly raised adaxially and abaxially, higher-order veins forming a conspicuous reticulum that is distinctly raised on both surfaces, rarely indistinct; petiole 5.4-12 mm long, canaliculate, sparsely appressed-pubescent to glabrous. Inflorescences axillary, usually from the axils of fallen leaves, 1-3 flowered, pubescent; peduncles 1 per axil, 1.5-2.5 mm long; pedicels 1-3 per peduncle, 3.5-8.5 mm long, 1-1.3 mm thick; bracts (2) 3-5, evenly spaced up to 1/2-2/3 distance from base, persistent, uppermost 1.1-2.9 mm long, ovate, apex obtuse; buds linear-subulate to linear-lanceolate, occasionally falciform, apex acute, occasionally uncinate. Sepals spreading at anthesis, nearly free to 1/3-connate, 2.2-4.2 mm long, 3.0-3.5 mm wide, coriaceous, ovate to broadly triangular, apex acute, sericeous abaxially. Petals yellow, yellow-orange, or caramel-colored, the inner petals red except for the cream to yellow base and apex in vivo ; outer petals erect or slightly spreading at anthesis, 17.6-35 mm long, 2.5-5.1 mm wide at base, 1.3-3.4 mm wide at midpoint, fleshy, linear, apex acute, appressed-pubescent adaxially but with a glabrous patch at base, appressed-pubescent abaxially; inner petals erect at anthesis, 3.5-6.7 mm long, 2.2-4.6 mm wide, fleshy, rhombic to ovate, apex acuminate, the acumen 1.4-3.1 mm long, base with undifferentiated margin, pubescent on acumen and glabrous toward base adaxially, keeled and pubescent in distal half to either side of the keel abaxially. Stamens 70-77; fertile stamens 1.6-2.2 mm long, quadrate, oblong, or clavate, apex of connective 0.4-0.7 mm long, shieldlike, overhanging anther thecae, puberulent or papillate, anthers 6-8-locellate, filament 0.3-0.9 mm long; outer staminodes 1.2-2.5 mm long, oblong-pentagonal, oblong, or ovate, apex obtuse; inner staminodes 1.1-1.3 mm long, narrowly oblong, apex obtuse to truncate; staminal cone 2.1-2.4 mm in diameter, 0.3-0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels (4-) 7-12; ovaries 1.0-2.1 mm long, narrowly oblong, golden-tomentose, stigmas loosely connivent, 1.4-2.9 mm long, linear, bearing glandular appendages. Torus flat, 2.3-3.0 mm in diameter. Fruit of up to 15 glabrate monocarps borne on a pedicel 9-15 mm long, 2.2-7 mm thick, glabrate; torus 6-14 mm in diameter, 5-10 mm high, subglobose to globose. Monocarps with black or dark purple exterior and pink to scarlet endocarp in vivo , 4.1-16.3 cm long, 0.6-1.2 cm wide, 0.6-1.1 cm thick, narrowly oblong, torulose to moniliform, somewhat falcate, apex rounded to a distinct beak up to 5 mm long, base contracted into a stipe 4-20 mm long, 2-6 mm thick, obliquely wrinkled, finely verrucose; pericarp 0.6-1.0 (2.0) mm thick. Seeds 1-7 per monocarp, in a single row, lying parallel to long axis, 9.5-19.8 mm long, 5.5-10.7 mm wide, 5.5-9.8 mm thick, oblong-ellipsoid, circular in cross-section, truncate at micropylar end, rounded at chalazal end, reddish brown to brownish black, smooth or slightly wrinkled, shiny, raphe/antriraphe raised, less distinct around chalazal end, micropylar scar 1.5-3.5 mm long, 1.5-2.5 mm wide, ovate; sarcotesta absent; aril orange to red in vivo , light brown when dried, brushlike, 5.5-9 mm in diameter, 3.9-4 mm high, fleshy, granular. Phenology. Specimens with flowers have been collected from all months of the year except December, although flowering appears more limited for specimens from the northeastern (February, May, and July) and southeastern (June, August-November) areas of the distribution, perhaps in relation to the more restricted seasonal rainfall patterns of these areas compared to the coast. Similarly, collections have been gathered from the coastal localities with fruits in February, May-June, August, and October-November, but only from November in the northeast, and May and August-October in the southeast. Figure 11. Xylopia rubescens . A Habit with fruit B Inner petal, adaxial surface C Outer petal, adaxial surface D, E Stamens, abaxial view F Staminode, abaxial view G Stigma apex H Inflorescence I Seed, longitudinal view. A from Brenan et al. 8022 (K), B-H from Angus 870 (MO) I from Breteler et al. 10446 (WAG, spirit collection). Distribution (Fig. 12 ). Occurs from Guinea and Liberia in West Africa east to South Sudan and south to Angola, Zambia, and Mozambique at elevations from sea level up to 1690 m. This species occurs in a range of wetland habitats, including gallery and other riparian forests, swamp forest, Raphia swamps, and pond edges. Local names. Fonde de marais ( Aubreville 1511 ), fonde des rivieres , fula-bifum ( Bates 561 ), iyere (Kakwa, Myers 13598 ), mabama ( Gossweiler 8957, Gossweiler s. n. ), majindi (Banda, Tisserant 1885 ), mbowobowo (Kimatengo, Ruffo & Kisena 3235 ), mtua (Pahouin du Gabon, Fleury 33135 ), mut ( Gossweiler 8747 ), muyombo (Kiluba de Kabongo, Schmitz 5771 ), mwengele (Wemba, Brenan & Greenway 8022 , Kiswahili or Kirungu, Hopper 1 ), nitumbo ( Gossweiler 8747 ), ntom (Ntomou, Focho et al. 2010 ), ntua (Pahouin de Gabon, Fleury 33135 ), odjobi (Ntoumou, Focho et al. 2010 ; Yaounde-boulou , Letouzey 1611 ), odjobi nzam (Cameroon, Focho et al. 2010 ), odzobe ( Yaounde , Fleury 33135 ), odzǖ'ē ( Tessmann 1913 ), ojobi ( Bates 1317 ). Figure 12. Distribution of Xylopia rubescens . Bolder lines represent country borders, fainter lines lakes and major rivers. Additional specimens examined. GUINEA . Macenta, Soulakoto, 10 Aug 1949 (st), Adam 5910 (MO, P); Macenta, Tenemadou 10 Aug 1949 (st), Adam 5911 (MO, P); Macenta+Beyla Prefectures, Simandou Range, 8°33'41"N , 8°53'06"W , 868 m , 23 Mar 2008 (fl buds), Tchinegue 3113 (K). LIBERIA . Troh, Sangwin River drainage, 6 May 1948 (fr), Mayer 150 (US). IVORY COAST . Route de Dabou, Marais de l'Agneby , 27 Nov 1968 (fl), Ake Assi 10378 (MO); Banco, Aubreville 1511 (BR, P); Assinie dans le Sanvi, Chevalier 16321 bis (P); Abidjan , Banco Forest Reserve, 9 Oct 1974 (fr), de Koning 4070 (WAG-2 sheets), 2 Feb 1975 (fl, fr), de Koning 5296 (WAG), 22 Feb 1976 (fl), 6615 (MO, WAG-2 sheets); Abidjan , 3 km N of Armebe , about 10 km NE of Dabou, c. 5°22'N , 4°19'W , 15 May 1979 (fr on label), de Kruif E 20 (WAG-2 sheets); Abidjan , along Agneby R., not far from Armebe , about 10 km W of Dabou, 5°21'N , 4°20'W , 21 May 1979 (yg fr), de Kruif 57 (WAG). GHANA . Ankasa Forest Reserve, Mpatabo-Elubo Road, Enti 890 (MO); Atuabo Road near Chrisan, 24 Oct 1973 (st), Enti & Awriah R1136 (K, MO). NIGERIA . Prov. Calabar, Eket District, Stubbs Creek Forest Reserve, 3 May 1951 (fr), Amachi FHI 24311 (K); "Southern Nigeria," without specific locality s. d. (fl), Kennedy 1960 (A, B, BM, K); Jamieson River , Sapoba, 1935 (fl), Kennedy 2752 (BM); without definite locality, van Meer 985 (WAG); S. Nigeria, Thomewill s. n. (K); Benue Plateau , Jos District, 30 km S of Jos, 9°45'N , 8°50'E , 3 Feb 1972 (fr), Wit & Wit FHI 64927 (K, WAG-2 sheets). CAMEROON . Bitye, Yaunde, 1919 (fl), Bates 1317 (BM, MO); environs de Duala, Jun 1917 (fl, fr), Fleury 33135 (P); Vuneli, 1 Feb 1928 (fl), Hedin 1668 (OWU, P); marecage du Niagoul entre Koumbou et Miambo, 14 Apr 1959 (fl, fr), Letouzey 1611 (K-3 sheets, P); pres Akok Bikele, 3 Mar 1962 (fl), Letouzey 4464 (K, P); station du Cacaouer de N'Koemvone , 14 km on the road from Ebolowa to Ambam, 2°49'N , 11°08'E , 11 Apr 1975 (fl), de Wilde 8166 (B, BR, K, MO, P, WAG); Bipindi, Mimfia Bergen, Jan 1903 (fl), Zenker s. n. (F, NY). CENTRAL AFRICAN REPUBLIC . Oubangui, reg. de Yango, Mar 1920 (fl), Allouette s. n. (L); Manovo-Gounda-St. Floris National Park, 9.3 km S of Koumbala Pende confluence on Pende Creek, 8°21'N , 21°14'E , 610 m 15 May 1984 (fl), Fay 6639 (MO, P); Yalinga, 15 Jul 1922 (fl), Le Testu 3998 (BM, P); Waka, bassi[n?] riv. Dangava, 10 May 1925 (fl), Tisserant 1885 (BM, BR, P). SOUTH SUDAN . Equatoria, Yei, Libogo, Khor Ini, 19 Nov 1940 (st), Myers 13586 (K); Libogo, Yei, 27 Nov 1940 (fr), Myers 13598 (K). EQUATORIAL GUINEA . Bioko: Malabo-Luba, Estrada km 46, 3 Nov 1986 (fl, fr), Carvalho 2646 (B, BM, F, FI-T, K-2 sheets, MO, NY, WAG).- Rio Muni: Nkolentangan [bei Alen , Tessmann 1913 ], Span. Guinea-Nintod, Engong, 450 m , 24 Feb 1908 (fl), Tessmann 160 (K). GABON . 5-15 km NW of Ndjole , Missanga, 0°05'S , 10°45'E , 13 Nov 1991 (fr), Breteler & Jongkind 10446 (WAG-2 sheets); Uboro sur le Ramboue , Chevalier 27105 (P); environs de Libreville, Nov 1898 (fl), Klaine 186 (OWU, P); Bitam, region entre Ogooue et Cameroun, 9 Mar 1933 (fl), Le Testu 9019 (BM, BR, OWU, P); Obour, region entre Ogooue et Cameroun, 1 May 1933 (fl), Le Testu 9095 (BM, P). REPUBLIC OF THE CONGO . NE de Brazzaville, route des falaises de Douvres, village de Gamakala, mare a Sphaignes, 22 Jun 1960 (fl), Descoings 5904 (P); Marais du Djili, pres de Brazzaville (M. Congo ), Koechlin 5299 (P); champ de ter de Lifuola, mare de Gawa Kala, 12 Aug 1966 (fl), Lissouba 22 (P); Tourbiere de Ngamakala, 24 Feb 1973 (fl), Makany 882 (K); Plateau des Cataractes, region de Boko, 4 Aug 1963 (fr), de Nere 404 (P); Route de Brazzaville, forets du Mayumbe, Jan 1891 (fl), Thollon 4026 (P). DEMOCRATIC REPUBLIC OF THE CONGO . Equateur : Bamania [next to Mbandaka], 1930 or 1934 (fl), Lebrun 1246 (A, B, K).-Haut-Katanga: Left-hand side of Luapula R. to Fort Rosebery, 5 Oct 1947 (fl, fr), Brenan & Greenway 8022 (BM, EA, K-2 sheets, NY, P); a 6.2 km au NNW du Post de Katshupa, Plateau de Kundelungu, foret galerie de la riviere Luanza, a 500 m de la cource, en lisiere , 1690 m , 28 Oct 1968 (fl), Malaisse 6127 (K, P); Kundelungu, Oct 1950 (fl, fr), Schmitz 3176 (BR).-Haut-Lomami: Kamunza, 25°50'E , 7°02'S , fin Sep 1957 (fl), Schmitz 5771 (BR); Riviere Kilwesi, Prov. Katanga , Terr. Mitwaba, Parc national de l'Upemba , 19 Aug 1948 (fl), de Witte 4121 (WAG-2 sheets).- Kasai-Oriental : Gandajika, Prov. Kasai , 26 Jun 1956 (fl), Risopoulos 531 (K, WAG).- Kinshasa : Bas-Congo , Kinshasa , Maluku, Lac Vert, 13 Apr 1970 (fl), Breyne 864 (MO).- Kongo Central : Kisantu, 1 Nov 1949 (fr), Callens 2143 (K); Bas-Congo , route Kisantu-Madimba, 20 Sep 1952 (fl), Troupin 2104 (BR); Leopoldville, Territ. Boma, Estuaire du fleuve Congo , 6 Sep 1958 (fl), Wagemans 2000 (K).- Kwango : entre Kwango-Wamba tete de sources de la Mpfulula [ca. 5°10'S , 16°40'E ], 700 m , 14 Aug 1944 (fl), Germain 2793 (K).-Lualaba: environs de Kolwezi, Tuissesu Kanamwamfwe, 25°25'114E, 10°37'645S, 22 Aug (fl), Malaisse & Kisimba Kibuye 117 (K).-Tshopo: lac Yandja (Yangambi), 19 May 1944 (st), Louis 16985 (K). UGANDA . Amua River, West Madi, May 1948 (fl), Eggeling E.5775 (K-2 sheets). TANZANIA . Kassanga area, Ufipa District, 4000-4500 ft , 1960 (fl), Hopper 1 (EA, K, TFD); T8, Mbinga District, Kitanda ponds at Ndondo Village-Liparamba at 1180 m , 2 May 1991 (fr), Ruffo & Kisena 3235 (K, TFD). ANGOLA . Sumba, Peco, proximum flumen Zaire (Congo), 0 m, 15 May 1923 (fl, fr), Gossweiler 8747 (BM, K-3 sheets, MO, US); Sumba, Peco, proximum flumen Zaire (Congo), Feb 1925 (fl, fr), Gossweiler 8957 (BM, K, US); Sumba, Peco, proximum flumen Zaire (Congo), Aug 1926 (fl), Gossweiler 9126 or 9126A (B, BM, US); Sumba, Peco, proximum flumen Zaire (Congo), Jul 1926 (fl), Gossweiler s. n. (BM, US); Hochland von Quela, 1200 m , Oct 1938 (fl), Nolde 845 (BM) . ZAMBIA . Northern Province , Chinsali District, Shiva Ngandu, 29 Nov 1952 (fl), Angus 870 (BM-2 sheets, EA, K, MO, NY [as White 870 ]); Luwinga, 15 May 1958 (st), Angus 1942 (K); Kawambwa, 23 Aug 1957 (fl), Fanshawe 3557 (K); Chinsali, 25 Sep 1967 (fl, fr), Fanshawe F10170 (K); Shiwa Ngandu, 3 Aug 1938 (fr), Greenway & Trapnell 5573 (EA, K); Northern Province , Chinsali District, Chipomo Falls National Monument, along Chimanabuwi River, 11°44'58"S , 32°00'17"E , 1310 m , 17 May 1994 (fr), Harder et al. 3145 (MO), (fr), Harder et al. 3164 (MO); Mwinilunga, 10 Sep 1955 (fl), Holmes 1192 (K); Inono Valley Falls above Mukoma, 3000', 21 Dec 1954 (fl), Richards 3696 (K); Abercorn District, Kasulo, 5000', 11 Jan 1955 (fl), Richards 4036 (K); Abercorn District, Lucheche R., Abercorn, 1200 m , 10 Oct 1964 (fl, fr), Richards 19193 (BR, K); Abercorn District, Lunzuwa Falls, 26 Oct 1952 (fl), Robertson 184 (BM, EA, K, P); Kamuswazi River, Tunduma Road, 5000', 20 Jul 1970 (fr), Sanane 1293 (K); Western Province , Fort Rosebery District, near Samfya Mission, Lake Bangweulu, 30 Aug 1952 (st), White 3165A (K-2 sheets), near Samfya Mission, Lake Bangweulu, 30 Aug 1952 (fr), White 3182 (K); Western Province , Mwinilunga District, tributary of Zambezi River, 4 mi N of Kalene Hill Mission, 20 Sep 1952 (fl), White 3309 (K, MO). MOZAMBIQUE . Dist. Mocambique , adm. Mecuburi-Serra Chinga, no vale entre as duas Chinga 10 e Chinga 2, Aguiar Macedo 3274 (DSM). Xylopia rubescens is readily recognized by the combination of relatively large leaves, which are often orange-red on the abaxial surface of the leaf in dried specimens, twigs with light gray bark, narrow flowers that are often clustered on leafless portions of twigs, stalked glands on the stigmas, and distinctly moniliform monocarps. Throughout its wide range, it is a wetland species. The orange-red cast to the dried leaves, from which the species epithet is presumably derived, is especially pronounced in young leaves. The stalked glands on the stigmas (Fig. 11g ) are unique in the genus. William Hawthorne (personal communication) reported that a gland is present on the adaxial surface of the petiole apex in this species, but this characteristic is not discernible in dried specimens and is perhaps only useful for identifying living plants. Specimens are occasionally misidentified as X. aethiopica , which shares the relatively large and subcoriaceous leaves, narrow flower buds, and torulose monocarps, and which is also occasionally found in wet habitats. Xylopia rubescens differs from X. aethiopica , however, in having short inner petals, larger but fewer (<15 per fruit) monocarps, and seeds with the brushlike aril typical of sect. Neoxylopia . Xylopia rubescens has a number of taxonomic synonyms, which represent minor variations connected by intermediates among the collections examined in this study. Engler and Diels (1901) separated X. humilis from X. rubescens on the basis of the less prominent vein reticulum of the lower leaf surface, but we found this character to vary widely over the range and to be a function of leaf thickness. Engler and Diels, acknowledging that they had not seen the type material of X. rubescens , distinguished X. klaineana from it on the basis of its thinner leaves that lacked the reddish cast. Le Thomas (1969) reduced X. klaineana to a variety of X. rubescens , but drew a sharper distinction between the two taxa, calling attention, again, to the thinner leaves with more prominent venation on the abaxial leaf surface, and also to the much larger seeds of the type of X. klaineana compared to the type material of nominate X. rubescens . Study of material from the entire distribution, however, revealed that mature fruits of this species, such as those present on the type specimen of X. klaineana , are seldom collected, and that larger seeds are found from scattered localities across the range. While the seeds of the type specimen of X. klaineana are the largest seen for this species ( 17-20 mm long), they are followed closely, in descending order, by seeds of specimens from Gabon ( 17-18 mm long, Breteler & Jongkind 10446 ), Cameroon ( 15-16 mm long, Fleury 33135 ), Bioko, Equatorial Guinea ( 14.6-14.9 mm long, Carvalho 2646 ), and Ivory Coast ( 14.5 mm long, de Koning 4070 ). Smaller seeds from throughout the range are sunken and paler brown, with incompletely formed ruminate endosperm, all characteristics of immature seeds. Thus seed size alone is insufficient for maintaining X. klaineana as a distinct taxon . The label of the type specimen of Xylopia batesii describes the plant as having a shrub or vine habit. The leaves of the type are rounded to nearly truncate at the base, and the outer petals are gradually tapered. While this combination of characters is not usual for X. rubescens , we found each character to vary independently. For example, the specimen Harder 3145 from Zambia was described as a lianescent shrub but it has cuneate leaf bases, the specimen Gossweiler 6222 from Angola ( type of X. gossweileri ) has strongly rounded leaf bases but has abruptly narrowed petals and was collected from a tall tree, and the specimen Carvalho 2646 from Bioko has very broad petals (over 3 mm wide at the midpoint), strongly cuneate leaf bases, and was collected from a tree 12-15 m tall . Xylopia rubescens has the second-widest distribution of any African Xylopia species after X. aethiopica and appears to be a wetland opportunist. It has not been collected from most of the Congo River basin within the Democratic Republic of the Congo , where a suitable habitat would seem to be present. Plant associates reported in Cameroon included Ancistrophyllum sp., Cyrtosperma sp., Gaertnera sp., Gardenia imperialis , Mitragyna sp., Raphia sp., and Rhynchospora corymbosa ; in Zambia Garcinia mbulwe , Mitragyna stipulosa , Syzygium elegans , and S. cordatum were noted to be growing with X. rubescens . Seeds of Xylopia rubescens are eaten and dispersed by three species of hornbills and three species of monkeys in the Dja Reserve of southern Cameroon . Seeds of X. rubescens defecated by hornbills were shown to germinate and at a higher rate than uneaten seeds and seeds recovered from gray-cheeked mangabey fecal samples showed 40% germination when planted ( Whitney et al. 1998 , Poulsen et al. 2001 ) Tessmann (1913) reported that the leaves of this plant (called there Xylopia zenkeri ) were used in a former time by Fang people in Equatorial Guinea to make a preparation for the treatment of elephantiasis. The leaves were ground together with those of Dioscorea preussii between pieces of bark and then cooked, the resulting water then administered in an enema.