Xylopia staudtii Engler & Diels, Notizbl. Koenigl . Bot. Gart. Berlin 2: 298. 1899.

Johnson, David M. & Murray, Nancy A., 2018, A revision of Xylopia L. (Annonaceae): the species of Tropical Africa, PhytoKeys 97, pp. 1-252 : 45-48

4. Xylopia staudtii Engler & Diels, Notizbl. Koenigl. Bot. Gart. Berlin 2: 298. 1899. Figs 4A , 13

Xylopicrum staudtii (Engler) Kuntze, Deutsch. Bot. Monatsschr. 21:173-174. 1903. Type. CAMEROON. Southwest Province, Johann-Albrechtshöhe, 1896, A. Staudt 530 (holotype: B!; isotypes: K! [000105614], P! [00169112, 00169113]).

Xylopia mayombensis De Wildeman, Bull. Jard. Bot. État 4: 386. 1914. Type. DEMOCRATIC REPUBLIC OF THE CONGO ["Belgian Congo"]. Kongo Central Province, Ganda-Sundi, 1913, Comte J. de Briey 219 (holotype: BR!; isotypes: BR! [8825421, 8825438, 8825445, 8825506]).

Description.

Tree up to 35 (-50) m tall, d.b.h. up to 80 cm, bole straight, slender, with branching stilt roots and small buttresses extending from the base, secondary branches horizontal, forming a conical to rounded crown; bark whitish to orangish gray or gray brown, rough, somewhat scaly. Twigs brown to gray, eventually light gray to light brown, appressed-pubescent, the hairs 0.3-0.4 mm long, soon glabrate; nodes frequently with two axillary branches. Leaf with larger blades 5.1-11.8 cm long, 2.0-5.6 cm wide, subcoriaceous to coriaceous, discolorous, often paler abaxially, oblanceolate to obovate, occasionally elliptic, apex blunt-acuminate, acumen 2-3 mm long, or acute, base cuneate and decurrent on petiole, glabrous adaxially, sparsely sericeous abaxially; midrib impressed to plane adaxially, raised abaxially, secondary veins brochidodromous, 7-11 per side, diverging at 45-70° from the midrib, plane or raised adaxially, strongly raised abaxially, higher-order veins forming a conspicuous reticulum that is slightly raised adaxially and strongly raised abaxially; petiole 2.5-9 mm long, canaliculate, sparsely appressed-pubescent or glabrate. Inflorescences axillary, 1-2 (-3)-flowered, sparsely pubescent to glabrate; peduncle 1 per axil, ca. 0.5-2.4 mm long; pedicels 2 per peduncle, 2.5-7 (-8) mm long, 0.8-1.3 mm thick; bracts 2-4, evenly spaced on pedicel, 1.1-2 mm long, semicircular, occasionally tearing down the center as the inflorescence enlarges, apex rounded, occasionally with a tiny apiculum; buds ovoid, apex obtuse. Sepals spreading at anthesis, 1/4-1/2-connate, 1.6-2.7 mm long, 2.6-3.5 mm wide, coriaceous, broadly ovate to semicircular, apex obtuse to acute, appressed-pubescent. Petals yellow to yellow-orange in vivo, outer petals slightly spreading at anthesis, 5.8-9.6 mm long, 4-5.2 mm wide toward base, 3.5-4.3 mm wide at midpoint, fleshy, ovate, apex acute, appressed-pubescent but with a glabrous patch at base adaxially, velutinous or appressed-pubescent abaxially; inner petals erect to slightly spreading at anthesis, 4.1-8.4 mm long, 2.0-3.2 mm wide toward base, 1.7-2.5 mm wide at midpoint, chartaceous, rhombic to broadly lanceolate, apex acute, base with undifferentiated margin, slightly keeled abaxially, pubescent adaxially, pubescent on apical half and glabrous and verrucose on basal half abaxially. Stamens ca. 100-120; fertile stamens 1.6-2.1 mm long, clavate, apex of connective 0.3-0.5 mm long, shieldlike but center formed into a conical point, overhanging anther thecae, pubescent, anthers 6-7-locellate, filament 0.3-0.5 mm long; outer staminodes 1.4-1.7 mm long, oblong to broadly clavate, apex obtuse to obliquely truncate; inner staminodes 1.7-2.6 mm long, clavate, apex rounded; staminal cone 1.3-2.1 mm in diameter, 0.4-0.9 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 3-11; ovaries 1.3-2.4 mm long, narrowly oblong, tomentose, stigmas free or loosely connivent with tips spreading, 2.6-4.6 mm long, linear, studded with round tubercles on the side and pubescent toward base. Torus flat, 2.2-3 mm in diameter. Fruit of up to 5 glabrate or sparsely appressed-pubescent monocarps borne on a pedicel 7-13 mm long, 3-8 mm thick, sparsely pubescent to glabrate; torus 6-16 mm in diameter, 4.3-5 mm high, depressed-globose. Monocarps with green exterior and scarlet endocarp in vivo, 3.7-9.8 cm long, 1.2-2.1 cm wide, 1.0-1.7 cm thick, oblong and somewhat falcate, occasionally weakly torulose, apex rounded or with a curved beak or mucro 1.3-3 mm long, base contracted into a stipe 7-15 mm long, 2.5-6 mm thick, finely wrinkled, strongly verrucose; pericarp 0.7-2.5 mm thick. Seeds 1-5 per monocarp, in a single row, lying parallel to long axis, 14-19 mm long, 9-12.9 mm wide, 9-11 mm thick, oblong-ellipsoid, oblong-elliptic in cross section, truncate at micropylar end, rounded at chalazal end, brown to black, smooth, shiny, raphe/antiraphe forming a raised ridge encircling the seed, micropylar scar 1.5-3.5 mm long, 1.5-2.0 mm wide, elliptic to circular; sarcotesta absent; aril bright yellow or orange, rarely pink or violet in vivo, amber-colored when dried, brushlike, 10-14 mm in diameter, 4.8-8 mm high, fleshy, granular.

Phenology.

Specimens with flowers and with fruits have been gathered in all months of the year and with fruits from all months except March. In Sierra Leone, "flowers appear during the rains from July to August and fruits are ripe by October" ( Savill and Fox 1967); in Ghana, the flowering season is given as June to October, and the fruiting season as January to March ( Hall and Swaine 1981).

Distribution

(Fig. 10 ). Occurs from Sierra Leone to Ghana, and then again from eastern Nigeria east to southwestern Uganda and south to the Cabinda Province of Angola and east-central Democratic Republic of the Congo; high forest and occasionally freshwater swamp forest, at elevations from sea level up to 1350 m. In Sierra Leone, the trees have a preference for moist valleys, and can be weedy in timber regeneration plots ( Savill and Fox 1967).

Local names.

Diroma (Gossweiler 7992), drehn (Cooper 60, 234), duanan (Ghana, Vigne 982, Hall and Swaine 1981), fofois (Gola, Voorhoeve 19), fondé ( Aubréville 38, 66, 1941), niumbi (Kitetela, Germain 7631), nkala (Hauzer 29; Bulu, de Wilde 7941), ntom (Ntoumou, Focho et al. 2010), odjobi (Ntomou, Focho et al. 2010; Letouzey 8178), takon-blu-chu (Cooper 139), yengetomei (Sierra Leone, Savill and Fox 1967).

Additional specimens examined.

SIERRA LEONE. Yengetumeh M., Kambin Hangha, 21 Aug 1918 (buds), Aylmer 239 (K); Neaboi Valley, Kambui Forest Reserve, 1 Apr 1955 (fr), Jordan 2024 (K); Gola Forest, Bagbe Line, 21 May 1952 (buds), Small 724 (B, K, MO, P). LIBERIA. Saniquellie, Kitoma, 21 Mar 1959 (st), Adam 16813 (MO), 17 Dec 1969 (fr), Adam 25287 (MO); 20 Oct 1971 (st), Adam 26378 (MO); Kakata, Blazie, 7 Mar 1959 (st), Adam 16733 (MO, WAG); Ganta, 30 km S Ganta, 15 Oct 1975 (fr), Adam 29894 (MO); from vicinity of Firestone Plantations along Dukwia ["Dukwai"] R., Monrovia, 3 Oct 1928 (fl, fr), Cooper 60 (BM, F, GH, K, NY, US, YF), 17 Nov 1928 (fl, fr), Cooper 139 (BM, F, GH, K, NY, PH, US, YF), 23 Feb 1929 (st), Cooper 234 (BM, F, K-2 sheets, NY, PH, US, YF); Firestone Plantation #3, 2 Aug 1926 (fl, fr), Linder 66 (A, K-2 sheets); near Blohni, Blohni River drainage, 28 Apr 1948 (fr), Mayer 97 (US); Bong Range, 200 m, 19 Jul 1960 (fr), Voorhoeve 19 (WAG). IVORY COAST. Abidjan, Aubréville 38 (B, K, P), 66 (K, P, US); Banco, undated (fr), Aubréville 1941 (A, P); forêt du Téké, Adzopé-Abidjan km 73, 5°33'N, 4°03'W, 11 Feb 1969 (fr), Bamps 2044 (BR); Abidjan, Banco Forest Reserve, part N of Route du Rail, 29 Apr 1976 (fr), de Koning 6833 (WAG-3 sheets). GHANA. Tarkwa, Subiri F. R. (Benso), Sept 1951 (fl), Andoh A30/51 (FH 5561) (B, K, NY, P); Neung Forest Reserve (W), Dompim, 16 May 1974 (fr), Enti FE-1315 (K, MO, WAG); Neung Forest Reserve, nr. Bonsa River, Tarkwa Dist., 3 Sept 1981 (fr), Enti FE-2095 (MO); Atewa F. R., 1800', 25 Feb 1971 (fl, fr), Hall GC 43251 (MO); Western Province, Elubo, approx. 22 km ESE towards Takoradi, along Elubo-Taboradi road, then N 8 km on road to Ankasa Forest Reserve, N of Ankasa River, 05°17'N, 02°45'W, 80 m, 14 Jul 1995 (fl, fr), Harder et al. 3406 (MO); Abosso, Aug 1926 (fl), Vigne 982 (K, P). NIGERIA. Southern Nigeria, Central Province, 1931 (fl), Rosevear C.21 (K). CAMEROON. East Province, Department Haut-Nyong, Dja Reserve, Bouamir Research Area, 90 km SE of Akonolinga, 03°12'N, 12°49'E, 640-700 m, 24 Aug 1994 (fl), Fogiel 864 (MO-2 sheets); 22 km à l’Ouest de Masea (village situé à 50 km au SSW de Yokadouma, 4 Jul 1963 (fl), Letouzey 5404 (P); Mebemonko, 20 km NO d’Oveng, 24 Oct 1966 (fl, fr), Letouzey 8178 (K, P); près Nteigne, Pk 108, Route Mintom-Mbalam, near Djoum, Jan 1973 (fl), Letouzey 11854 (K); colline a l’ENE de Mbalam 140 km ESE de Djoum près Souanke-Congo, 20 Jan 1973 (fl, fr), Letouzey 11865 (BR, K-2 sheets, P); Übergangs- und Kampfgebiet gegen die Savanne an der Nord-grenze der Hylaea südlich des Sanaga zwischen Jaunde und Dengdeng unweit der Vereinigung von Lom (Sanaga) und Djerem, etwa 88 km NO Jaunde, Feb 1914 (fl), Mildbraed 8171 (K); Southwest Province, forested lower slopes of Mt. Cameroon above Batoke, 4°05'N, 9°05'E, 300-600 m, 24 Apr 1984 (fl), Thomas 3463 (B, K, MO); Prov. Southwest, Takamanda Forest Reserve, footpath from Mbilishi to Kaluma, 6°15'N, 9°26'E, 650 m, 1 May 1987 (fr), Thomas et al. 7401 (MO); Station du Cacaoyer de N’koemvone, 11 km on the road from Ebolowa to Ambam, 2°49'N, 11°08'E, 31 Jan 1975 (fl), de Wilde 7941 (B, BR, K, MO, P); Station de Cacaoyer de N’Koemvone, 14 km on the road from Ebolowa to Ambam-track crossing the Mvila river, 2°49'N, 11°06'E, 4 Mar 1975 (fl), de Wilde 8029 (B, K, MO); South Province, hill above Nlonacko near village Ebianemeyong, c. 2°26'N, 10°21'E, 500 m, 12 Dec 1998 (fl), de Wilde et al. 12161 (MO); Mimfia, Mar 1913 (fl), Zenker 246 (B, G, GH, M, MO, P, US, WAG); Bipinde, 1908 (fl), Zenker 3653 (BM, F, G, K, L, M, MO, US, WU), Bipinde, Mimfia, Aug 1909 (fl), Zenker 3953 (BM, F, G, K, L, M, MO, P, WU); Bipinde, 1903 (fl), Zenker 4862 (B, BM, G, K, L, M, MO, P, PR, US). EQUATORIAL GUINEA. Río Muni: Près de la frontière gabonaise, chantier forestier à l’est de Cogo, 1°05'N, 10°00'E, 3 May 1989 (bud), McPherson 14003 (MO); Bebai, Campo-gebiet, Weg u Tkum [locality is in NE corner of modern Equatorial Guinea ( Tessmann 1913)], 18 Nov 1908 (fl), Tessmann 644 (K). GABON. Estuaire: S of Estuaire du Gabon along Remboué River, British Gas site, 00°12'S, 10°01'E, 10 m, 11 Jan 1991 (fl, fr), McPherson 15113 (MO); côté plantation Sogacel 3 km N de Ndouaniang, 12 Aug 1984 (fl, fr), Wilks WIL 991 (WAG-2 sheets).- Haut-Ogooué: Plateau Batéké National Parc, 02°06'59"S, 14°04'03"E, 421 m, 26 Feb 2003 (fr), Niangadouma & Walters 144 (MO, WAG).- Ngounié: new rd from Mouila to Yeno, 5 km either side of Kembela village, 1°42'S, 11°23'E, 20 Jul 1986 (fl, fr), Thomas & Wilks 6515 (K, MO, P).- Nyanga: région du Nyanga, Inganga, Mayombe Bayaka, 20 May 1914 (fl), Le Testu 1748 (BM, MO, P, US); forêt du Mayombe Bayaka, près de Tchibanga, 10 Dec 1914 (fl), Le Testu 1913 (BM, K-2 sheets, MO, P); chantier CEB, 35 km SW of Doussala, 2°30'S, 10°30'E, 19 May 1985 (fl), Reitsma et al. 1071 (MO, NY, RSA, WAG); chantier CEB, ca. 50 km SW of Doussala, 2°36'S, 10°35'E, 14 Jun 1985 (fr), Reitsma & Reitsma 1168 (BISH, MO, NY, RSA).- Ogooué-Maritime: Toucan, ca. 01°47'S, 09°53'E, 9 Jun 2002 (fl, fr), Bourobou Bourobou et al. 707 (MO-3 sheets).- Ogooué-Ivindo: M’Passa Field Station, near Makokou on Riviere l’Ivindo, 8 Jul 1981 (fr) Gentry 33219 (MO); Ile Ipassa, Makokou, 17 Jun 1972 (fr), Hladik 2334 (P); Monts Iboundji, 27 Dec 1930 (fl), Le Testu 8630 (BM, BR, P).- Woleu-Ntem: Oyem, région entre Ogooué et Cameroun, 9 Sep 1933 (fl), Le Testu 9287 (BM, BR, K-2 sheets, P).-Province unknown: Billagone, 100', 22 May 1938 (fl), Thomson 2 (K). REPUBLIC OF THE CONGO. Route du chantier de Boungolo (Pointe-Noire), 31 Jan 1966 (fl), Farron 4892 (K, P). DEMOCRATIC REPUBLIC OF THE CONGO. Équateur: Entre Bokatola and Bikoro, Sep 1930 (fl), Lebrun 1425 (BM, K, MO, NY, RSA, US).- Ituri: Ituri District, Lodjo, SW of Lodjo village, 2°03.09'N, 29°59.51'E, 1080 m, 26 Jan 2011 (fr), Bytebier et al. B 3367 (K, MO).- Kongo Central: Kisafu [Maduda], 10 Oct 1951 (fr), Hauzer 29 (BR).-Sankuru: Katako-Kombe, Rubber Plantation, Jun 1952 (fr), Germain 7631 (BR).- Sud-Kivu: Mukono, Terr. Mwenga, 8 Jul 1959 (fl, fr), Leonard 4877 (BR).-Tshopo: Tsangi Terr., Yangambi, 120 m, 5 Mar 1952 (fl), Toussaint 918 (K).-Tshuapa: Piste Yalikungu-riv. Tshuapa, Terr. Ikela, 25 Nov 1958 (fl), Evrard 5212 (BR, K). ANGOLA. Mayumbe, M’bulu hills, source of N’Zanga River, 11 Apr 1919 (fl, fr), Gossweiler 7992 (BM, BR, K-3 sheets). UGANDA. Impenetrable Forest, Kigezi, Apr 1946 (fl), Butt 45 (ENT, not seen, photo at K); [U2], Rukungiri District, Kayonza, Bwindi forest, Ishasha Gorge, 0°53'- 1°08'S, 30°25'- 30°35'E, 1350 m, Apr 1998 (fl), Hafashimana 0504 (K).

Xylopia staudtii is the tallest of any Xylopia species, becoming a canopy tree of up to 50 m. The elaborate stilt roots of this species, described in detail by Jeník (1970), consist not only of adventitious stilt roots emerging from the trunk up to one meter above the ground, but also stilted pneumatophores ("peg roots") that arise from lateral roots up to 10 m distant from the tree trunk. These striking roots suggest adaptation to swamp forests, although the species is not restricted to such habitats.

With its broad flower buds, Xylopia staudtii is most similar to Xylopia africana , also sharing with that species the oblong thick-walled monocarps and large seeds with a brushlike aril. In fact, many collections of X. staudtii made by Zenker in Cameroon were distributed as X. africana . The lone taxonomic synonym, Xylopia mayombensis De Wild., was based on a specimen with petals at the larger end of the range of petal size for X. staudtii but is not otherwise exceptional for the species.

Sunderland et al. (2003) reported X. staudtii to be a dominant tree in lowland (300-500 m), mid-elevation (500-800 m), and montane (800-1500 m) forests of the Takamanda Reserve, having the second-highest relative density and the fourth-highest basal area of all tree species sampled in montane forest plots. The seeds of X. staudtii have been reported as a food item for two hornbill species ( Whitney et al. 1998), four species of mangabeys and guenons ( Sourd and Gautier-Hion 1986, Poulsen et al. 2001), and mandrills ( Lahm 1986). The nutrient analysis of the arils of X. staudtii by Sourd and Gautier-Hion (1986) showed high levels of lipids and proteins, suggesting that the species provides a high-value food resource to these dispersers and perhaps others. Some seeds defecated by gray-cheeked mangabeys and by hornbills germinated ( Whitney et al. 1998, Poulsen et al. 2001).

Figures

Figure 4. Fruits and seeds of representative Xylopia species. A Xylopia staudtii from Democratic Republic of the Congo B Xylopia aethiopica from Republic of the Congo C Xylopia quintasii from Cameroon D Xylopia tenuipetala from Mozambique E Xylopia collina from Mozambique F Xylopia gracilipes from Mozambique G Xylopia hypolampra from Gabon H Xylopia tanganyikensis from Tanzania. A by Quentin Luke B by David Harris C, G by Thomas L. P. Couvreur D by Jonathan Timberlake E, F by Mervyn Loetter H by Noriko Itoh. C reproduced with permission of Thomas L. P. Couvreur and of the American Society of Plant Taxonomists D reproduced with the permission of Jonathan Timberlake and of the Board of Trustees, Royal Botanic Gardens Kew.

Figure 10. Distributions of Xylopia africana, X. globosa, and X. staudtii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Figure 13. Xylopia staudtii. A Outer petal, adaxial view B Inner petal, adaxial view C Stamen, abaxial view D Carpel E Habit F Fruit G Seed, view of micropylar end H Seed, lateral view I Close-up of inflorescence. A-D from Le Testu 8630 (BM) E, I from Evrard 5212 (BR) F from Reitsma 1071 (WAG) G, H from Reitsma & Reitsma 1168 (BISH).