Xylopia hypolampra Mildbraed, Notizbl. Koenigl . Bot. Gart. Berlin, Append. 27: 18. [11 Oct] 1913.

Johnson, David M. & Murray, Nancy A., 2018, A revision of Xylopia L. (Annonaceae): the species of Tropical Africa, PhytoKeys 97, pp. 1-252 : 138-141

31. Xylopia hypolampra Mildbraed, Notizbl. Koenigl. Bot. Gart. Berlin, Append. 27: 18. [11 Oct] 1913. Figs 4G , 42E-F

Xylopia brieyi De Wildeman, Bull. Jard. Bot. État 4: 385. 1914. Type. DEMOCRATIC REPUBLIC OF THE CONGO ["Belgian Congo"]. Kongo Central Province, Ganda-Sundi, 8 Oct 1911, J. de Briey 108 (lectotype, here designated: BR! [0000008824844]; isotypes: BR! [0000008824790, 0000008824806, 0000008824813, 0000008824837], US! [1270066]).

Type.

CAMEROON. East Region, zwischen Station Lomie, Bidjum und dem Dscha-Posten , 600-700 m, 13 May 1911, J. Mildbraed 5183 (holotype: B!; isotype: HBG! [502479]) .

Description.

Tree up to 43 m tall, d.b.h. up to 80 cm, bole round, rising to small open crown of horizontal branches; bark brown-gray, smooth, very finely cracked in all directions. Twigs brown, eventually grayish black, tomentellous, the hairs 0.2-0.4 mm long, eventually glabrate; no nodes seen with two axillary branches. Leaf with larger blades 5.7-7.5 cm long, 1.4-1.9 cm wide, subcoriaceous, concolorous, lanceolate, apex attenuate or rarely acuminate, the acumen ca. 12 mm long, and minutely retuse or obtuse, base obliquely cuneate, rarely rounded or somewhat angular, glabrous except for the pubescent midrib adaxially, densely golden- or silvery-sericeous abaxially; midrib plane adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 10-18 per side, diverging at 50-70° from the midrib, these and higher-order veins indistinct adaxially, obscured by indument abaxially; petiole 4-5.5 mm long, semi-terete, pubescent. Inflorescences axillary, 1-3-flowered, pubescent; peduncle absent; pedicels superposed in leaf axil, 2.2-3.8 mm long, 1.0-1.3 mm thick; bracts 3-4, evenly spaced and somewhat imbricate, persistent, 1.8-2.3 mm long, ovate to broadly ovate, apex obtuse to rounded; buds linear, often falciform, apex acute, sometimes uncinate. Sepals slightly spreading at anthesis, 1/3-connate, 2.1-3.2 mm long, 2-2.5 mm wide, coriaceous, broadly triangular, apex acute, pubescent abaxially. Petals pale green to yellow in vivo; outer petals slightly spreading at anthesis, 25-28.7 mm long, 2.5-2.6 mm wide at base, 1.0-1.1 mm wide at midpoint, coriaceous, filiform, apex obtuse and slightly incurved, densely puberulent except for glabrous basal concavity adaxially, sericeous except for a glabrous patch at base abaxially; inner petals more or less erect at anthesis, 16-31 mm long, 1.9-2.5 mm wide at base, 0.6-1.0 mm wide at midpoint, coriaceous, filiform, apex acute, base with undifferentiated margin, longitudinally ridged and puberulent on both surfaces. Stamens ca. 100; fertile stamens 1.0-1.5 mm long, narrowly oblong, apex of connective purplish red in vivo, ca. 0.2 mm long, shieldlike, overhanging anther thecae, minutely papillate, anthers 7-8-locellate, filament 0.4-0.6 mm long; outer staminodes 1.3-1.7 mm long, oblong, apex obtuse to truncate; inner staminodes ca. 1.1 mm long, oblong, apex rounded to truncate; staminal cone 1.3-1.7 mm in diameter, 0.6-0.7 mm high, completely concealing the ovaries, rim laciniate. Carpels 7-12; ovaries 0.7-0.8 mm long, oblong, pubescent, stigmas connivent or sometimes free at the very tips, 1.6-2.5 mm long, filiform, with a tuft of hairs at the apices. Torus flat, slightly concave under the ovaries, 1.5-2.2 mm in diameter. Fruit of up to 8 glabrate monocarps borne on a pedicel 2.5-6 mm long, 3-4.8 mm thick, with the bracts persistent, glabrate; torus 4.5-12 mm in diameter, 3.5-7.5 mm high, depressed-globose. Monocarps with a greenish brown exterior flecked with pale brown lenticels, sometimes tinged with cinnamon or red, and pink-red endocarp in vivo, 2.6-4.1 cm long, 1.1-2.2 cm wide, 1.5-2.1 cm thick, obovoid to oblong or ellipsoid, rarely globose, not torulose, apex rounded, sessile and rounded to truncate at base, often marked by longitudinal ridges but somewhat sunken between them so that the cross-section is bluntly angled, densely lenticellate; pericarp 0.5-1.4 mm thick, fibrous, woody. Seeds up to 10 per monocarp, in two rows, lying perpendicular to long axis, 7.1-10.6 mm long, 6.3-7.9 mm wide, 4.2-5.7 mm thick, elliptic, ovate, oblong or nearly circular, wedge-shaped to semicircular in cross section, truncate at micropylar end but micropylar scar bent to the side, rounded at chalazal end, light reddish brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 1.3-4 mm long, 1.4-2 mm wide, ovate to circular; sarcotesta greenish white in vivo; aril absent.

Phenology.

Collections with flowers have been obtained from November to June, and those with fruits in all months of the year except September; in Lopé National Park, Gabon, a peak of flowering was observed in October and November, followed by production of fruits from June to August (E. Bush and K. Abernethy, personal communication).

Distribution

(Fig. 43 ). Occurs from central Cameroon east to southwestern Central African Republic and south to the Cabinda Province of Angola and southwestern Democratic Republic of the Congo, where it grows in evergreen or semi-deciduous forest, sometimes along forest edges, and in gallery forest, at elevations of 400-900 m. In the northern Republic of the Congo, seedlings are reported as growing on roadsides (congotrees.rbge.org.uk: Royal Botanic Garden Edinburgh); the report is probably reliable, although we have seen no X. hypolampra specimens from the Republic of the Congo.

Local names.

Abiès (Bulu, de Wilde 7963), canzi (Bayaka, LeTestu 1749), ekui (reported as timber trade name, ITTO), lucanga (Murta 43), lukanga ivembuka (lukanga jaune) (Sargos 141), molo-nzange (Lissongo, Tisserant 1246, 1385), ndong-eli np (+ Fang, Wilks WIL 1040), nyanghogha (Mitsogo, Wilks WIL 1040), odjobi (Foury 101), sangi (Babindjere, Harris & Fay 222).

Additional specimens examined.

CAMEROON. Bitya near River Ja, s. d. (fl), Bates 1757 (K); South Province, Department Ocean, Mvie, about 11 km (along a straight line) ENE of village Mvie, 12 km N of Akom II by road, 2°55'N, 10°39'E, 400 m, 28 Jan 1998 (fl), van der Burgt & Laan 364 (K, MO, WAG); Central Division, Gazette: Ndanan 1, near Mefou town, 3°37'29"N, 11°34'56"E, alt. 710 m, 8 Mar 2004 (fr), Cheek 11487 (K); without definite locality, 1935 (fl), Foury 101 (OWU, P); a 30 km au NE de Bange (km 75 route Yokadouma-Moloundou), 25 May 1963 (fr), Letouzey 5139 (P); Bipindi-Ebolowa, Aug or Dec 1913, Mildbraed 7618 (B, K); Dengdeng, Sommer 1914 (buds), Mildbraed 8827 (BM, K-4 sheets); 16 km on the road from Ebolowa to Minkok, 2°58'N, 11°17'E, 670 m, 6 Feb 1975 (fl), de Wilde 7963 (B, BR, K, M, NY, P, U, WAG). CENTRAL AFRICAN REPUBLIC. Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 13 Feb 1988 (fr only), Harris & Fay 222 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 27 Feb 1988 (fr), Harris & Fay 266 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 21 Mar 1988 (fr), Harris & Fay 319 (MO); Boukoko, 20 Nov 1948 (fl), Tisserant 1246 (K, P); 23 Feb 1949 (fr), Tisserant 1385 [fruit of Tisserant 1246] (P). GABON. Ngounié: St. Martin - Munungu, July 1939 (fl, fr), Walker s. n. or 3454 (BM, K, MO, P); 6 km SSE du village Bilengui, 2°01'S, 11°26'E, 5 Feb 1985 (buds), Wilks WIL 1040 (WAG).- Nyanga: Mayombe Bayaka, région du Nyanga, Inganga, 20 May 1914 (fl), Le Testu 1749 (BM, K, MO, P); Tchibanga, 21 Feb 1919 (fl), Le Testu 2023 (BM, F, MO--2 sheets, P).- Ogooué-Ivindo: forêt des Abeilles, 40 km SSW of confluence of Ogooué-Ivindo, 00°30'S, 12°02'E, 5 Aug 1993 (fl, fr), Dibata 1171 (K-2 sheets); Bélinga, Mines de Fer, 700-900 m, 4 Jun 1966 (fr), Hallé 3736 (P); Réserve de la Lopé, au sud d’Ayem, chantier SOFORGA, 0°25'S, 11°30'E, 13 Mar 1989 (st), McPherson 13763 (F, MO, NY); ca. 25 km ENE of Booué, 0°02'S, 12°06'E, 18 May 1987 (fr), Reitsma et al. (MO, NY, RSA); Reserve de Lopé-Okanda, west-central region of tourist zone, top of "Point of View" hill, 00°10'47"S, 11°34'48"E, 363 m, 3 Nov 2000 (fr), Stone et al. 3171 (MO); MPAM/ Lopé River, Lopé Reserve, 0°15'S, 11°40'E, 16 May 1991 (fl), White LJTW 0483 (MO); road Mékambo to Makokou, 4 km W of Mbela-Baya, 0°58.5'N, 13°52'E, 500 m, 31 Dec 2000 (fl, fr), Wieringa et al. 3748 (WAG).- Ogooué-Lolo: About 30 km E of Lastoursville, 0°40'S, 13°00'E, 19 Nov 1991 (fl, fr), Breteler & Jongkind 10590 (MO, WAG); about 20-40 km NNE of Koumémayong, 0°15'N, 11°55'E, 13 Apr 1988 (fl, fr), Breteler et al. 8669 (WAG); Makande surroundings, about 65 km SSW of Booué, ca. 0°41'S, 11°55'E, 21 Jan 1999 (fr), Breteler et al. 14716 (WAG); région de Lastoursville, 1929-1931 (fl), Le Testu 8094 (BM, BR, K-2 sheets, NY, P, US); km 16 E-most road on chantier 19 branching off 21 km from Lastoursville direction Koula-Moutu, 0°56'S, 12°35'E, 23 Nov 1988 (fr), van der Maesen 5790 (MO, WAG).-Woleu-Ntem: without definite locality, May (fr), Louis et al. 3419 (MO).-Province unknown: Kouilou infr., Sargos 141 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central: Luki, 10 Dec 1947 (fl), Donis 1617 (K); INEAC, Luki, Mayumbe Prov. Kinshasa, Terr. Lukula, 27 Mar 1959 (st), Mahieu 292 (WAG), 27 Marh 1959 (fl, fr) Mahieu 293 (WAG); Luki, vallée de la Minkudu à flanc de esteau, 27 Jun 1927 (fl, fr), Toussaint 2395 (K, MO, P, US, WAG); Leopoldville Prov., Boma Territory, Luki, 7 Mar 1955 (fr), Wagemans 956 (K). ANGOLA. Mayombe, Oct-Nov 1921 (st), Dawe 267 (K); Buco Zau, 28 Jul 1916 (fr), Gossweiler 6532 (BM); Mayumbe, Buco Zau, Dec 1916 (fr), Gossweiler 7225 (BM); Cabinda-Chiaca, na Estrada para Buco Zau, 15 Mar 1959 (fl), Murta 43 (BM).

Xylopia hypolampra , with its distinctive narrow coriaceous abaxially sericeous leaves, is readily separable from other African Xylopia species. The pedicels are always short, such that the flowers and fruits appear sessile in the leaf axils. The outer surface of the monocarps at maturity is brown and strongly marked with lenticels, and typically splits into three segments instead of the usual two. The monocarps are often longitudinally ridged and bluntly angled when dry.

Xylopia hypolampra becomes a slender small-crowned canopy tree in forests across its distribution and appears to be locally common. Associates mentioned by collectors include " Sterculiaceae " (two separate collections from Cameroon and Central African Republic), Megaphrynium macrostachyum , Piptadeniastrum africanum , and species of Albizia , Celtis , and Entadophragma . A photograph of flowers (Couvreur 568 from Bélinga, Gabon, Nov 2013), shows a small beetle visiting the flower, but the species could not be determined, nor is it known whether the insect was behaving as a pollinator. Hornbills and, perhaps less frequently, monkeys (ex Harris & Fay 266) feed on the fruits and seeds; at the Dja Preseerve site in Cameroon, hornbills were particularly effective in extending the seed shadow for individual trees ( Holbrook and Smith 2000) .

Hutchinson (1923) observed the similarity of the leaves of Xylopia hypolampra to those of a number of Neotropical species of the genus such as X. sericea and X. discreta , implying a phylogenetic connection between South American and African species, but recent phylogenetic work has shown that Xylopia hypolampra is not closely related to any tropical American species ( Stull et al. 2017).

The original German description of Xylopia hypolampra given by Mildbraed in 1913 makes no mention of a type specimen. A Latin description and citation of a type specimen were provided by Mildbraed and Diels (Bot. Jahrb. Syst. 53: 445, 1915), but in the meantime (1914) the name Xylopia brieyi , a taxonomic synonym for X. hypolampra , was published by De Wildeman. All of these dates precede the requirement for a Latin diagnosis (ICN 2012, Article 39.1) and for citation of a type (ICN 2012, Article 40.1) so the 1913 description constitutes valid publication and the name X. hypolampra with Mildbraed as the sole author is accepted. The holotype for Xylopia hypolampra is extant at B and thus the lectotypification provided by Le Thomas (1969) of a duplicate at HBG was unnecessary.

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 42. Xylopia pynaertii, X. mildbraedii, and X. hypolampra. A, B X. pynaertii A Habit B Fruit C, D X. mildbraedii C Fruit D Habit E, F X. hypolampra E Habit F Fruit. A from McPherson 13825 (MO) B from Letouzey 12317 (P) C from Breteler et al. 12632 (WAG) D from Reitsma & Reitsma 2816 (NY) E from Le Testu 2023 (F) F from Le Testu 8094 (BM).

Figure 43. Distributions of Xylopia villosa, X. letestui, and X. hypolampra. Bolder lines represent country borders, fainter lines lakes and major rivers.