Baum, 1995, A Systematic Revision of Adansonia (Bombacaceae), Ann Miss Bot Gard, 82:440-470
II. Adansonia section Adansonia
Trees with irregular, often very broad trunks and irregular crowns. Flowering during the wet or dry season. Flower buds globose, approximately as long as broad; borne on long pendulous peduncle/ pedicels. Petals white, broadly obcordate, equally long and broad. Androecium white; staminal tube ca. 3-6 cm long, free filaments 720-1600, ca. 3-5 em long. Fruit varying in shape, persistence of the calyx, and indumentum; pericarp thick and woody. Seeds usually less than 12 mm long, reniform, and laterally flattened. Germination phanerocotylar.
Adansonia digitata L., Syst. Nat. ed. 10, 2: 1144. 1759. Adansonia bahobab L., Sp. Pl. 2:960. 1763. Adansonia baobab Gaertn., Fruct. 2: 253, t. 135. 1791. Boababus digitata (L.) Kuntze, Rev. Gen. 1: 66. 1891. TYPE: 862.1 LINN (lectotype, designated by Robyns, 1980).
Ophelus sitularius Lour., Fl. Cochin. 412. 1790. Adansonia situla (Lour.) Spreng., Syst. 3: 124. 1826.
Steud., Nom. Bot., ed. 2: 24. 1840. Adansonia integrifolia Raf., Sylva Tell., 149. 1838. TYPE: Not seen, probably destroyed.
Adansonia sphaerocarpa A. Chev., Vigit. Rig. Tombouctou. In Actes Congris Int. Bot. 1900: 271. 1901. TYPE: Mali. Timbouctou, Fouta-Djalon, Chevalier 12424 (holotype, P).
Adansonia digitata var. congolensis A. Chev., Bull. Soc. Bot. Fr. 53: 493. 1906. TYPE: San-Thomi Island. 1906. TYPE: Congo. Brazzaville, Chevalier 4230 (holotype, P).
Adansonia somaliensis Chiov. Fl. Somala, 8: 30. 1932. Provisional name and therefore invalidly published.
Usually massive deciduous trees reaching 25 m in height and up to 10 m diam., with single or multiple, cylindrical or fluted, often buttressed trunks and spreading, rounded crowns. Branches irregularly distributed, massive. Bark gray, smooth to irregularly tuberculate. Leaves 5-7(-9)-foliolate; petioles pubescent or glabrous; stipules caducous; leaflets sessile to subsessile, varying greatly in size, medial leaflet 5-15 x 3-7 cm, usually elliptic-obovate, with acuminate apices and decurrent bases; glabrous or with simple or clumped hairs; margins entire. Flowers produced during dry or wet season; buds globose with an acute-conical apex, solitary, rarely paired; flower stalk pendulous, 15-90 em long. Calyx lobes (3-)5, triangular, green and tomentose to scabrous outside, cream and villous within, reflexed, 5-9 x 3-5 cm, fused into a broad (5 cm diam.) disc below. Petals white, crumpled in bud, broadly obovate, approximately equal in length to breadth, 4-8 x 4-8 cm, narrowing to a thickened base. Androecium, white, comprising a 3-6-cm cylindrical or tapering staminal tube, surmounted by 720-1600 (Davis & Ghosh, 1976) free filaments, ± equal in length to the staminal tube. Ovary, conical-ovoid or globose with a thick indumentum of upward-pointing hairs; 7-9 deeply intruded placentae. Style white, bent over at right angles or rarely straight; densely villous below, glabrous above, fitting loosely into staminal tube and persisting after floral abscission. Stigma white with irregular lobes. Fruit variable; globose to ovoid to oblong-cylindrical, calyx lobes persistent or caducous; pericarp up to 8-10 mm thick, woody, with few embedded longitudinal fibers, covered in a velvety indumentum of yellowbrown or greenish hairs. Seeds reniform, laterally flattened, 10-13 x 8-10 x 4-5 mm. Germination phanerocotylar.
Representative specimens examined.. WEST AFRICA. BURKINA FASO: Ouagadougou to Sapone, km 1516, Bassayam, 12°12'N, 1°33'W, 18 Nov. 1980 (1, fr), J. Lejoly 80/217 (BR). CAPE VERDE ISLANDS: near Porto Prago, St. Iago, 7 May 1861 (1), Anon s.n. (E). CAMEROON: Marona, Aug. 1945 (fl, 1), A. Vaillant 100 (P). DAHOMEY: Mid Dahomey, Bassas country, BassasZoumi and vicinity, 9-10 May 1910 (l, fl), Chevalier 23641 (P). GHANA: Amansare, 2 July 1913 (fl, 1), N. P. Ashanti 513 (K). GUINEA: banks of the Niger, 19 Jan. 1909 (R,1), Chevalier 20453 (K, P). IVORY COAST: Ferkessedougou to Ouango Fitini, 13 Mar. 1969 (1), P. SENEGAL: Kaslack distr., Menirah Village, 5 May 1940 (l, fl), J.-G. Adam 27199 (MO). TOGO: NE Agouenyive (AgouevO, 17 Apr. 1978 (fl, I), Zepernik 124 (K). SIERRA LEONE: Jigaya, 28 Sep. 1914 (1, fl), V. If! Thomas 2799 (K). CENTRAL AFRICA. ZAIRE: M'vuazi, 28 Dec. 1949 (I, fl), R. Devred 648 (BR, K). NORTH/ EAST AFRICA. CHAD: Bogor Sieke near Logone, 26 Aug. 1969 (1), Fotius 1689 (P). EGYPT: Cairo, Schweinjiurth 1605 (US). ETHIOPIA: road from Gondar to Axum, 265 km from Gondar near Takazza River, 5 June 1968 (fl, I), G. J. H. Amshoff 4973 (BR, MO). KENYA: Meru National Park, just S of Rojewero main bridge, 18 Dec. 1972 (1, imm. fr), J. Ament 444 (K); Mombassa near Lineoni Ferry, Feb. 1970 (fl), Tweadie 3782 (K). SOMALIA: S Somalia, Bur Akaba, E foot of Mountain, 20 June 1983 (fl, I), J. B. Gillett & C. F. Hemming 24910 (K). OMAN: Wadi Ghazir, 2 July- 1982 (1, buds), Jlaconochie .3523 (E, K). SUDAN: Djerme (I), Chevalier 30,55 (BR). TANZANIA: Iringa distr., Ruaha National Park, 2km NNW of Msernbe at Nlbagi track, 22 Oct. 1970 (fl), A. Bjornstadt 657 (K). Zanzibar, Massazine, 25 Nov. 1960 (1, fl), H. G. Faulkner 2735 (BR, K). YEMEN: Taiz Prov., Samsarah, 35 km S of Taiz on road to Turbah, 23 May 1984 (1, fl), K. J. Gordon 3300 (E). SOUTHERN AFRICA. ANGOLA: near Andongo, Feb. 185 7 (1, fl), IVelwitsch 5415 (BM). BOTSWANA: Umtali distr., Hot Springs, 22 Oct. 1948 (fl, 1), iV. C. Chase 3728(BM). MALAWI: Northern prov., Nkhata Bay distr., Nkata Bay, Chikale Beach, 5 Dec. 19, 6 (fl), J. Pawek 12000 (K). MOZAMBIQUE: Mulanve distr., Nambwale village near Tunitulu hill, Lake Chilwa, 27 Nov. 1980 (fl, 1), J. D. Chapman 5188 (BR). NAMIBIA: Ombalantu, 1 Apr. 1973 (I, fl, fr), R. J. Rodin 9201 (ECON, MO). SOUTH AFRICA: Zoutspansberg, Transvaal, 12 Nov. 1932 (fl, I), Obermeyer et al 69 (K). ZAMBIA: 2 mi. N of Sinazezi, Gwerabe valley, It bite 2627 (K). ZIMBABWE: Victoria Falls, 13 No,. 1919 (fl, 1), 1.. Shantz 416 (K). INDIAN OCEAN. COMORES: Mayotte, Chissioi Caroni (islet off SW coast), 27 July 1979- (fl, 1), D. Lorence 2800 (MO). MADAGASCAR: Mahajanga, large tree in center of town near the sea, 20 Oct. 1991 (1, fl), Baurn 329 (MO, P, TAN); around villages near Lac Gnamby, near Mt. Tsitondroina, Dec. 1905 (1, fl), Perrier de la Bathie 1019bis (P); around village of Anaboringy near Soalala (Ambongo), Mar. 1903 (1), Perrier de la Bathie 5734 (P). FRANCE. REUNION: St. Dents, Nov. 1973 (l, fl), F. Friedman 2461 (P). %IAURITIUS: Port Louis, 17 Dec. 1975 (1, fl), D. Lorence & J. Gueho 17639 (P). ASIA. INDIA: Banda, NWP, .-lug. 1901 (1, fl), A. Bell 712 (K); Madras, St. Thomas Mount, 1856 (fl, 1), Drew s.n. (E). SRI LANKA: Mannar district, Tirukketisvaram, 11 Dec. 1970 (fl, fr), F. R. Fosberg 53631 (US); Jaffna district, Delft Island, A. Robyns 6966 (BR, E, K). TAIWAN: Pingtung City, Chang 10168 (A). PACIFIC. HAWAII. Oahu: Honolulu, Queen's Hospital, 14 Sep. 1950 (fl, 1), O. Degener 20716 (NY). CARIBBEAN. ANTIGUA: Donovans Estate, 26 Sep. 1938 (fl, 1), 11. E. Box 1,550 (BM). GRENADA: St. Georges, July 1905 (1, fl), IV. E. Broadway s.n. (F). CUBA: vicinity of Soledad, Santa Clara Prov., Aug. 1940 (fl, 1), R. A. Howard 4188 (A). HAITI: Pleine Centrale, Michel de I'Adalave, 18 Feb. 1925 (1, fl), E. L. Ekrnan 3258 (US). MARTINIQUE: without further locality (fl), P. Duss 2032 (NY). PUERTO RICO: Mita, 1layaguez, 1 Oct. 1981 (l, fl), A. H. & P. Liogier 32387 (NY). ST. CROIX: Ham's Bay, 16 July 1897 (1, fl), J- J. Ricksecker 451 (E, F). ST. KITTS: Bassterre, the park, Aug. 1967 (fl, t), R. K. Wadsworth 579 (A). U.S.A. Florida: Fairchild Botanical Garden, 15 May 1970 (I, fl), W T. Gillis 9418 (A).
Distribution The distribution of Adansonia digitata was previously described by Miege (1974), Lucas (1971), and Wickens (1983). It is indigenous in semiarid sub-Saharan Africa, extending from Angola, through Southern Africa to East Africa, as far north as southern Sudan and Ethiopia. The extensive populations in West Africa are isolated from those in East Africa by a major, and not fully explained, gap which includes the whole of the Central African Republic (Miege, 1974; Wickens, 1983). It should be noted that the current distribution of A. digitata in Africa is partly anthropogenic with naturalized populations, e.g., in Zaire (Miege, 1974; Wickens, 1983). It has been introduced by humans throughout the tropics (see specimen localities above).
Wickens (1983) reported that in Africa Adansonia digitata is mainly found in drier lowland areas (up to 1250 m in Sudan) having 200-800 mm annual rainfall (extremes of 90 mm and 1400 mm). Well-drained sandy soils seem to be preferred, although the plants are also found on lateritic soils around the margins of seasonal pools and along rivers.
The populations in Madagascar have been the subject of some controversy. Miege (1974) suggested that the Malagasy Adansonia digitata could be relics of the populations that colonized continental Africa. However, since most A. digitata in Madagascar are associated with villages, it is more likely that they were recently introduced by Arab traders (Jumelle & Perrier de la Bāthie, 1910; Perrier de la Bāthie, 1952b; Wickens, 1983). This latter explanation is supported by the documented transport of A. digitata to Zanzibar, India, and Sri Lanka (see Burton-Page, 1969; Vaid, 1978; Wickens, 1983).
Phenology. Varies greatly between localities. Leaves are shed during the dry season. Flowering can occur in the presence or absence of leaves.
Cytology. Chromosome counts from East and West Africa are 2n = 144 (Baker & Baker, 1968, Miege & Burdet, 1968) and 2n = 160 (Baum & Oginuma, 1994), with 2n = 96 and 128 reported for Southern Africa (Riley, 1960; Schroder in Wickens, 1983).
Taxonomy and nomenclature.Adansonia digitata has many diagnostic characters, including several that are unique in the genus and likely to be apomorphic, e.g., a pendulous flower, globose buds, and broad petals. I thus have no doubt that A. digitata is an exclusive group. However, the question of whether A. digitata is a basal, exclusive group is harder to answer. Chevalier (1906) argued for the subdivision of A. digitata into at least three species diagnosed by differences in fruit shape. However, I see no evidence that fruit shape diagnoses discrete groups and hence reject Chevalier's taxonomy. Without further studies of variation within A. digitata I cannot rule out the existence of exclusive subgroups, but in the absence of evidence for such subgroups, (e.g., fixed differences between West Africa, East Africa, and Southern Africa), I advocate that A. digitata be treated at the species rank.
Ethnobotany. A substantial body of literature documents the multitudinous uses of the roots, hollow trunks, bark, wood, leaves, flowers, and fruit of Adansonia digitata. Reviews and access to the ethnobotanical, anthropological, and economic literature are provided by: Chevalier (1906), Dalziel (1948), Adam (1962), Watt & Breyer-Brandwijk (1962), Owen (1970, 1974), Guy (1971), Wickens (1979, 1983), Armstrong (1983), Burkill (1985), and von Maydell (1986).
Conservation. Despite ongoing ecosystem destruction in Africa, Adansonia digitata is conservationally secure because of its wide ecological tolerance. Nonetheless, as pointed out by Wickens (1983), some management may be useful in ensuring that the species survives in areas where it is threatened by tree clearance or destruction by elephants.
