Chaetocarpus africanus Pax

Breteler, F. J., 2002, Novitates Gabonenses 46. A new Chaetocarpus (Euphorbiaceae) from Gabon, Adansonia (3) 24 (2), pp. 221-227 : 222-226

Chaetocarpus africanus Pax

In Engl., Bot. Jahrb. Syst. 19: 113 (1894).— Types: Pogge 112, 1384, 1388, Congo (Kinshasa), Mussamba (no 112) and Mukenge (no 1384, 1388) (syn-, B, delet.); neotype (designated here): Lisowski 66707, Congo (Kinshasa), Kasai, near Kanango , fr., fl.b. Nov. 1981 (holo-, BR; iso-, WAG), see note.— Figs. 1 , 3 , 4 .

SPECIMENS EXAMINED (selection). — ANGOLA: Cavaco 1267, Lunda, fl. Oct.-Dec. (P, WAG); Exell & Mendonça 736, Lunda, fr. Apr. (BM); Gossweiler

Breteler F.J.

10577, Sacandica, fr. Dec. ( BM) ; Gossweiler 11565, Lunda, fr. Apr. ( K) ; Gossweiler 13675, Dundo, fl. Oct. ( BM, K, P) ; Gossweiler 13885, Dundo, fl. Nov. ( BM, K, P) ; Gossweiler 14056 B, Dundo, fl. Mar. ( BM, K, P) ; Gossweiler 14056 C, Dundo, fr. ( BM) ; Lynes 340, Missão, fl. Dec. ( BR) ; Milne-Redhead 4242, Moxico, fr. Jan. ( BM, BR, K) ; Raimundo et al. 897, Huambo, fl. Aug. ( BR) ; Soares in Cavaco 52, Dundo, fl. Dec. ( P) . — CONGO (Brazzaville): Charvet 123, Brazzaville, fr. Feb. ( P) ; Chevalier 4041, Brazzaville, fr. July ( P) ; Chevalier 5022, between Nigoua and Ngantchou , fl. Aug. ( P); J. de Brazza 179, piste du Dielé, fr. Oct.-Nov. ( P, WAG) ; de Neré 430, Boko, fr. Aug. ( P) ; Deschamps 13066, Kouilou, fr. June ( BR) ; Descoings 7056, Gaboma, fl.b. June ( P) ; Descoings 7468, Makoua, ster. June ( P) ; Descoings 9631, 20 km Brazzaville-Foulakari, fl. Feb. ( P) ; Descoings 9831, falaises de Douvres, fr. Nov. ( P) ; Dowsett-Lemaire 1403, Tchissanga, fl. Dec. ( BR) ; Farron 4031, Moutampa, ster. Mar. ( P) ; Koechlin 5634, Hinda, ster. Dec. ( P) ; Sita 440, forêt de la Patte d’Oie, fr. Oct. ( P, WAG) ; Thollon 513, Brazzaville, fr. Nov. ( P, WAG) ; Thollon 1281, Loango, fl. Oct. ( P) ; Vermoesen 2440, Ngandu-Sedek, fr. June ( BR, K, P, WAG) . — CONGO (Kinshasa): Bamps & Malaisse 8195, Kyamascumba- Kolwezi, fr. Jan. ( BR, K) ; Bequaert 826, Kinshasa, fr. Oct. ( BR, P) ; Breyne 103, Kimuenza, fr. Mar. ( BR, WAG) ; Breyne 4061, Wombe, fl.b. Dec. ( BR) ; Callens 1899, Dembo, fr. Nov. ( BR) ; Callens 1964bis, Mpese, fl. Dec. ( BR) ; Claessens 294, Kole, fr. ( BR) ; Claessens 328, Katako Kombe , fr. Jan. ( BR) ; Claessens s.n., Boma, fr. ( BR, P) ; Compère 1359, Kimaza, fl. Jan. ( BR) ; Dechamps 10, Kakenge, fr. Feb. ( BR, K) ; Delvaux 63, Masondoye, ster. Feb. ( BR) ; Desenfans 1813, Sapeza, fr. Feb. ( BR) ; Devred 582, Mvuazi, fr. July ( BR, WAG) ; Devred 2077, Tono-Feshi-Kwango, fr. June ( BR, K, WAG) ; Dumont 128, Mikope, fl., fr. May ( BR) ; Dumont 222, Ilebo, fl. May ( BR, K, WAG) ; Evrard 4623, Nkinki-Pomandjoku, fr. Aug. ( BR, WAG) ; Evrard 4655, piste Yongo-Yenge, fr. Aug. ( BR, K) ; Flamigni 6174, Nioki, fr. Feb. ( BR) ; Flamigni 6397, Bokebene, fl. Oct. ( BR) ; Galliez 179, Elundu, fr. Dec. ( BR, K) ; Germain 7627, Katako Kombe , fr. June ( BR, K) ; Germain 7946, Mwene Ditu, fl.b. July ( BR, K) ; Gilbert 14582, Ipeke, fl. July ( BR, K, WAG) ; Gillardin 215, Bilala, ster. Feb. ( BR) ; Huart 80, Malondo, ster. June ( BR) ; Jans 809, Bokoro, fl. Oct. ( BR, WAG) ; Jespersen s.n., Watsi, fl.b. Nov. ( BR); E. & M. Laurent s.n., Kapinga, fr. Nov. ( BR) ; Lebrun 6090, between Kindu and Katako Kombe , fl. July ( BR, K) ; Lebrun 6721, between Mushie and Bolobo , fl. Dec. ( BR, K) ; Lebrun 6757 Bolobo , fl.b. Dec. ( BR, WAG) ; Lejoly 82/896, Bankana, fl. Dec. ( BR); A. Léonard 5500, Kitoko, fl.b. Aug. ( BR) ; Liben 1763, Badibanga, fr. Oct. ( BR) : Liben 1956, Miabi, fl.b. Nov. ( BR) ; Liben 2195, Tshondo, fr. Jan. ( BR) ; Lisowski 66707, Kananga, fr. Nov. ( BR, WAG), neotype; Nelis s.n., Bokala, fr. June ( BR) ; Pauwels 274, Kimvulu, fr. Oct. ( BR) ; Sapin s.n., Tshibangu, fr. Jan. ( BR) ; Schlechter 12554, Stanley Pool, fl.b. June ( BM, BR, K, P, WAG) ; Schmitz 2649, Dilolo, fr. Jan. ( BR) ; Toka 59, Lukolela, ster. May ( BR) ; Vanderyst 3094, Kikwit, fl. Jan. ( BR) ; Vanderyst 5533, Sanda, fl. June ( BR) ; Vanderyst 8578, Ipamu, fr. Jan. ( BR) ; Vanderyst 10157, Mpio-Mpio, fr. Aug. ( BR) ; Vanderyst 11175, Kamtsha, ster. Nov. ( BR, K) ; Vanderyst 16365, Mbau, fl. ( BR) ; Wagemans 1441, Boma-Banana, fr. Oct. ( BR, K) ; Wellens 249, Kizu, fl. Mar. ( BR) . — GABON: Breteler 6235, km 6 Moanda- Franceville , fr. Sep. ( BR, C, K, LBV, MO, P, PRE, SRGH, WAG) ; Breteler 6328, km 5 Moanda- Franceville , fl. Sep. ( AAU, B, BR, C, K, LBV, MA, MO, P, PRE, SRGH, WAG) ; Breteler & Jongkind 10709, 30 km E of Lastoursville, fr. Nov. ( K, LBV, MO, P, PRE, WAG); F. J. & B. J. M. Breteler 12394, 70 km E of Lastoursville , fr. Nov. ( G, K, LBV, MA, MO, P, PRE, WAG); F. J. & B. J. M. Breteler 12444, 10 km Moanda-Franceville, fl. Dec. ( BR, G, K, LBV, MA, MO, P, PRE, WAG); F. J. & B. J. M. Breteler 12447, 15 km Moanda-Franceville, fr. Dec. ( G, K, LBV, MO, P, PRE, WAG); F. J. & B. J. M. Breteler 12480, near Bakoumba, fl. Dec. ( BR, K, LBV, MA, MO, P, WAG) ; Breteler 15826, Ndambi, fl. Apr. ( WAG); J. J. de Wilde et al. 9920, 7 km SE of Franceville, fr. Dec. ( BR, G, K, LBV, MA, MO, P, PRE, WAG); J. J. de Wilde et al. 9965, 37 km E of Franceville, fl. Dec. ( K, LBV, MO, P, WAG); J. J. de Wilde et al. 9970, 37 km E of Franceville , fr. Dec. ( LBV, MA, MO, P, WAG) ; Dibata 1109, SSE of Moanda , fr. Aug. ( WAG) ; Le Testu 7127, Lastoursville , fl. Apr. ( P, WAG) ; Le Testu 7847, Lastoursville , fl. Jan. ( BR, P) ; Le Testu 7931, Lastoursville , fl. Feb. ( BR, P) ; Le Testu 8539, Lastoursville , fl. Nov. ( BR, P, WAG); A. M. Louis 1644, km 8 Moanda-Mounana, fr. Nov. ( WAG); A. M. Louis 3102, 60 km Franceville-Leconi, fl. June

(LBV); L. White 1319 , Lopé-Okanda Res., fr. Jan. (WAG); L. White 1338 , Lopé-Okanda Res., fr. Feb. (LBV). — ZAMBIA: Angus 510A, Kalene Mission, fl.b. Sep. (K); Mutimushi 3154, Chinyazzi R., fl. May (P); Mutimushi 3156, Mwinilunga, fr. May (K); Richards 16961, Mujileshi R., fr. Nov. (K); Robinson 5946, 6 km N of Kalene Hill, fr. Dec. (K); Robinson 5951, 6 km N of Kalene Hill, fl. Dec. (K); F. White 3322, N of Kalene Hill Mission, ster. Sep. (K).

NOTES. — The three syntypes on which PAX based his Chaetocarpus africanus were lost at Berlin. Duplicate material has not been found, neither at BR nor at K or P. The neotype designated originates from the same area where Pogge collected the numbers 1384 and 1388 .

The number of sepals in Chaetocarpus is very variable. This variation not only pertains to the differences between male and female flowers of the same species, but is also related to the continent from where the material originates. Based on the number of sepals and continental origin PAX & HOFFMANN (1912) subdivided the genus into three sections, one for the Asiatic species with 4 sepals, one for the American species with 5 sepals, and one for the single African species with 4 sepals in the male and 6-8 in the female flower. Although there is also variation in sepal number in Asia (see below) and America, the greatest variation and the highest number of sepals (9) is found in Africa. VAN WELZEN (1994) considered the, sometimes present, fifth and (rarely) sixth inner sepal in the Asian species to be petal remnants. These inner perianth elements, however, only show a small difference in shape and texture when compared to the most inner of the outer sepals, quite unlike the differences seen between sepals and petals in the related genus Trigonopleura ( WEBSTER 1994) . If VAN WELZEN is followed, the female flower of C. rabaraba Capuron from Madagascar with 9 perianth elements, and of C. africanus and C. gabonensis with 6-8 elements would have to be described as ‘‘petals present’’. In these flowers, however, there is no difference between the perianth elements that justifies a subdivision into sepals and petals. In the two continental African species of Chaetocarpus , however, there is a marked difference between the outer two sepals and the other ones, so that LÉONARD (1962) described this phe- nomenon as ‘‘sépales bisériés, inégaux’’. These outer two sepals are considerably smaller (see Fig. 1D and LÉONARD 1962, fig. 8A) and look like two bracteoles. This distinction is not seen in the calyx of the Asian and American species, with 4, respectively with 5 sepals. Are the outer two sepals in these extra-african species homologous with the two bracteole-like sepals in Africa? I suppose so. If these are true bracteoles as well, the Chaetocarpus calyx has undergone a considerable reduction in the number of sepals. The higher number of sepals in the female elements of C. africanu s and C. gabonensis may indicate a slower process of sepal loss than is observed in the male elements of the same species. The presence of a fifth and a sixth sepal in Chaetocarpus castanocarpus (Roxb.) Thwaites has then little to do with the loss of petals, but with that of sepals.

Figures

Fig. 1. — Chaetocarpus gabonensis Breteler: A, branchlet with stipules and flowerbuds; B,C, stipule, outside and inside respectively; D, Ƌ flower; E, young fruit; F, part of fruit; G, detail of fruit wall. — Chaetocarpus africanus Pax: H, branchlet with stipules and flowerbuds; I,J, stipule, outside and inside respectively; K, part of fruit; L, detail of fruit wall. (A-C, Breteler c.s. 13026; D, Breteler c.s. 15571; E, Breteler c.s. 15570; F-G. Louis et al. 832; H-J, Breteler c.s. 12447; K-L, Breteler 6235). Drawing by W. WESSEL-BRAND.

Fig. 3. — Distribution of Chaetocarpus in Gabon.

Fig. 4. — Distribution of Chaetocarpus africanus Pax.