LIST OF ABBREVIATIONS A.V.P.=O.Hedberg, Afroalpine Vascular Plants; B.J.B.B.=Bulletin du Jardin Botanique de l’Etat, Bruxelles; Bulletin du Jardin Botanique Nationale de Belgique; B.S.B.B.=Bulletin de la Société Royale de Botanique de Belgique; C.F.A.= Conspectus Florae Angolensis; E.J.=A.Engler, Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie; E.M.=A.Engler, Monographieen Afrikanischer Pflanzen-Familien und Gattungen; E.P.=A.Engler, Das Pflanzenreich; E.P.A.=G.Cufodontis, Enumeratio Plantarum Aethiopiae Spermatophyta; in B.J.B.B. 23, Suppl. (1953) et seq.; E. & P. Pf.=A.Engler & K.Prantl, Die Natürlichen Pflanzenfamilien; F.A.C.=Flore d’Afrique Centrale (formerly F.C.B.); F.C.B.=Flore du Congo Belge et du Ruanda-Urundi; Flore du Congo, du Rwanda et du Burundi; F.D.O.A.=A.Peter, Flora von Deutsch-Ostafrika; F.F.N.R.=F.White, Forest Flora of Northern Rhodesia; F.P.N.A.=W. Robyns, Flores des Spermatophytes du Pare National Albert; F.P.S.=F.W.Andrews, Flowering Plants of the Anglo-Egyptian Sudan or Flowering Plants of the Sudan; F.P.U.=E.Lind & A.Tallantire, Some Common Flowering Plants of Uganda; F.R.=F.Fedde, Repertorium Speciorum Novarum Regni Vegetabilis; F.S.A.=Flora of Southern Africa; F.T.A. =Flora of Tropical Africa; F.W.T.A.=Flora of West Tropical Africa; F.Z.=Flora Zambesiaca; G.F.P.=J.Hutchinson, The Genera of Flowering Plants; G.P.=G.Bentham & J.D.Hooker, Genera Plantarum; G.T.=D.M.Napper, Grasses of Tanganyika; I.G.U.=K.W.Harker & D.M.Napper, An Illustrated Guide to the Grasses of Uganda; I.T.U.=W.J.Eggeling, Indigenous Trees of the Uganda Protectorate; J.B.=Journal of Botany; J.L.S.=Journal of the Linnean Society of London, Botany; K.B.=Kew Bulletin, or Bulletin of Miscellaneous Information, Kew; K.T.S.=I.Dale & P.J.Greenway, Kenya Trees and Shrubs; K.T.S.L.=H.J.Beentje, Kenya Trees, Shrubs and Lianas; L.T.A.=E.G.Baker, Leguminosae of Tropical Africa; N.B.G.B.=Notizblatt des Botanischen Gartens und Museums zu Berlin-Dahlem; P.O.A.=A.Engler, Die Pflanzenwelt Ost-Afrikas und der Nachbargebiete; R.K.G.=A.V.Bogdan, A Revised List of Kenya Grasses; T.S.K.=E.Battiscombe, Trees and Shrubs of Kenya Colony; T.T.C.L.=J.P.M.Brenan, Check-lists of the Forest Trees and Shrubs of the British Empire no. 5, part II, Tanganyika Territory; U.K.W.F.=A.D.Q.Agnew (or for ed. 2, A.D.Q.Agnew & S.Agnew), Upland Kenya Wild Flowers; U.O.P.Z.=R.O.Williams, Useful and Ornamental Plants in Zanzibar and Pemba; V.E.=A.Engler & O. Drude, Die Vegetation der Erde, IX, Pflanzenwelt Afrikas; W.F.K.=A.J.Jex-Blake, Some Wild Flowers of Kenya; Z.A.E.= Wissenschaftliche Ergebnisse der Deutschen Zentral-Afrika-Expedition 1907– 1908, 2 (Botanik). FAMILIES OF VASCULAR PLANTS REPRESENTED IN THE FLORA OF TROPICAL EAST AFRICA The family system used in the Flora has diverged in some respects from that now in use at Kew and the herbaria in East Africa. The accepted family name of a synonym or alternative is indicated by the word “see”. Included family names are referred to the one used in, the Flora by “in” if in accordance with the current system, and “as” if not. Where two families are included in one fascicle the subsidiary family is referred to the main family by “with”. Foreword and preface (£3.00) Glossary (£23.50) Index of Collecting Localities (£18.50) PTERIDOPHYTA Actmiopteridaceae (£2.30) Grammitidaceae Polypodiaceae (£10.00) Adiantaceae (£15.00) Hymenophyllaceae Psilotaceae (£1.70) Aspleniaceae Isoetaceae Pteridaceae (£8.50) Azollaceae (£1.70) Lomariopsidaceae (£10.00) Salviniaceae (£1.40) Blechnaceae Lycopodiaceae Schizaeaceae (£3.40) Cyatheaceae Marattiaceae (£1.70) Selaginellaceae Davalliaceae (£1.70) Marsileaceae (£6.00) Thelypteridaceae Dennstaedtiaceae (£6.50) Oleandraceae (£6.00) Vittariaceae (£2.95) Dryopteridaceae Ophioglossaceae (£7.00) Woodsiaceae (£8.00) Equisetaceae (£1.70) Osmundaceae (£1.70) Gleicheniaceae (£2.30) Parkeriaceae (£1.70) GYMNOSPERMAE (£3.00) Cupressaceae Cycadaceae Podocarpaceae ANGIOSPERMAE Acanthaceae Aponogetonaceae (£3.90) Agavaceae Aquifoliaceae (£1.50) Aizoaceae (£4.50) Araceae (£10.20) Alangiaceae (£1.50) Araliaceae (£3.00) Alismataceae (£3.00) Arecaceae—see Palmae Alliaceae (£4.00) Aristolochiaceae (£3.00) Aloaceae (£14.50) Asclepiadaceae—see Apocynaceae Amaranthaceae (£22.00) Asparagaceae Amaryllidaceae (£5.10) Asphodelaceae (£6.00) Anacardiaceae (£8.50) Asteraceae—see Compositae Ancistrocladaceae (£1.85) Avicenniaceae—as Verbenaceae Anisophyllaceae—as Rhizophoraceae Annonaceae (£10.50) Balanitaceae (£6.00) Anthericaceae (£11.50) Balanophoraceae (£1.95) Apiaceae—see Umbelliferae Balsaminaceae (£11.80) Apocynaceae Basellaceae (£1.50) Parti (£20.50) Begoniaceae Part 2 Berberidaceae (£1.50) © 2003 Royal Botanic Gardens, Kew FLORA OF TROPICAL EAST AFRICA BALANITACEAE MARTIN J.S.SANDS Deciduous or semi-evergreen spiny trees or shrubs. Spines simple or branching, derived from the distal of 2 or more buds, axillary or at a varying supra-axillary interval1. Leaves alternate or spirally arranged, either reduced to simple, minute and usually triangular, mostly caducous, exstipulate scale-leaves, or bifoliolate, sessile or petiolate, with a linear or triangular, sometimes persistent, terminal foliole2; stipules caducous or persistent, triangular to filiform, entire. Flowers actinomorphic, sepals and petals free, bisexual, 4–5- merous, rarely solitary, usually in a 2–many-flowered, bracteate, mostly cymose and subumbellate to fasciculate inflorescence, borne at spineless or spiniferous nodes on the stem or spines. Sepals imbricate, often reflexed and caducous, one or both margins glabrous, silky-hairy within. Petals spreading, sometimes reflexed, usually irregular, bent or contorted at the apex, yellow to green, glabrous outside, glabrous or hairy within. Stamens 8–10, free, glabrous; anthers dorsifixed, 2-thecous, dehiscing by longitudinal slits. Disc intrastaminal, annular, succulent, corrugated and minutely papillose, surrounding the base of the ovary. Ovary superior, hemispherical to ovoid, 4–5-locular, each locule containing 1 pendulous ovule; style simple, terminal, glabrous, stigma small and simple. Fruit a 1-seeded drupe on a thickened pedicel; exocarp leathery or brittle, mesocarp variable from pulpy to fibrous and oily, endocarp hard, often woody, splitting distally at germination; seed with plano-convex cotyledons. Monotypic. For the purpose of this Flora, Balanitaceae is recognized as an independent family. The genus Balanites has been variously classified and its supra-generic position continues to be debated. Recent molecular work by Sheahan & Chase (Syst. Bot. 25(2): 380 (2000)) has shown that Balanites is embedded in the Tribuloid clade within Zygophyllaceae; the Angiosperm Phylogeny Group (Ann. Missouri Bot. Gard., 85:531– 553 (1998)) also include Balanites in Zygophyllaceae. BALANITES Delile, Descr. Egypte, Hist. Nat. 2:221, t. 28, 1 (1813); Sands in K.B. 56:1–128 (2001) Description as for the family. Nine species, two species in India and Burma, the others distributed throughout much of Africa, with one also occurring in Yemen and another extending into Arabia and the Jordan valley. Several species of Balanites are of economic importance in Africa. A major use is that of the fruit of several species, especially the ‘desert date’ (B. aegyptiaca) which is edible and yields a valuable oil as well as the pharmaceutically important steroid, diosgenin, and Flora of tropical East Africa 2 a saponin-glucoside toxic to cold-blooded animals that are hosts to guinea-worm and stages of bilharzia. The leaves and inflorescences have several uses including as vegetables. The wood of most species has many uses such as furniture making and turnery, and bark and roots especially are variously used in traditional medicine. All aerial parts are browsed by livestock. 1 distance above the subtending leaf 2 vestigial terminal leaflet KEY TO FLOWERING MATERIAL Balanites sp. ‘Omo Valley’ is known only from sterile material and therefore not included in this key. 1. Flowers 5-merous; petals hairy within 2 Flowers 4- or 5-merous; petals glabrous within 3 2. Tree usually more than 30 m high; spines forked or branching several times, the 1. B. spine-branches usually more or less equal; fruit 8–12 cm long wilsoniana Shrub or tree less than 20 m (rarely 25 m) high; spines simple or branching with 2. B. the spine-branches usually unequal; fruit usually less than 6 cm long, rarely to 8 maughamii cm 3. Spines not bearing flowers or leaves; ovary elongating early in development 3. B. aegyptiaca Spines bearing flowers or leaves; ovary not or scarcely elongating in early 4 development 4. Flowers 5-merous 4. B. pedicellaris Flowers 4-merous 5 5. Spines arising (1–)2–5(–10) cm above the subtending leaf axil; secondary 5. B. spines present; ovary hairy or glabrous rotundifolia Spines arising 0.5–2 cm above the subtending leaf axil; spines sometimes 6. B. glabra branching but secondary spines absent; ovary glabrous KEY TO STERILE SPECIMENS This key assumes the presence of spines or at least a field report of their occurrence. Spinules are small secondary spines borne on the primary spine and usually at a wide angle to it. 1. Spines naked without leaves or flowers or their scars 2 Spines bearing leaves or exhibiting leaf and/or flower or inflorescence scars 5 2. Small shrub less than 0.5 m high; spinules present; leaflets sharply acute or B. sp. ‘Omo apiculate 7. Valley’ Flora of tropical East Africa 3 Large shrub or small tree; spinules absent, leaflets obtuse, rounded or bluntly 3 acute to acuminate 3. Spines usually forked or branching with deflection of the primary spine, at least 4 on the trunk and main branches All spines simple, unbranched, or branch-spines rare, and short clearly 3. B. subordinate without deflection of the primary spine aegyptiaca 4. Large tree usually more than 30 m high; forked or branching spines mostly borne 1. B. on the trunk and branches, infrequent and simple on branchlets; remains or scars wilsoniana of inflorescences supra-axillary, up to 5(–10) mm above the axil; stipules caducous; indumentum of petioles and young growth silvery-grey Tree rarely exceeding 20 m high; spines on younger stems as well as on the 2. B. upper trunk and branches; remains or scars of inflorescences axillary; stipules maughamii usually persistent; indumentum of petioles and young growth yellowish- or greyish-green to buff 5. Spines sometimes branching, tending to widen dorsiventrally at the base, 0.5–3 6. B. glabra cm above the axil; spinules absent; foliage-leaves infrequent; scale-leaves occurring on the parent stem, sometimes persistent Spines frequently branching, scarcely widening at the base, 0.5–10 cm above the 6 axil; spinules often present; foliage-leaves frequent; scale-leaves only evident on growth or secondary spines 6. Primary spine and branch-spine/spinule supra-axillary intervals 0.5–1.2(–2.6) cm 4. B. and 1–2 mm respectively; leaflets broadly obovate to spathulate, cuneate; scale- pedicellaris leaves occurring on the spinules, or sometimes on growth, up to 1.3 mm long; stipules caducous Primary spine and branch-spine/spinule supra-axillary intervals (1–)2–5(–10) cm 5. B. and (2–)4–7 mm respectively; leaflets usually orbicular to broadly obovate, rotundifolia rounded or broadly cuneate; scale-leaves occasional on young growth, 2–3 mm long; stipules often persistent Flora of tropical East Africa 4 1. B. wilsoniana Dawe & Sprague in Dawe, Bot. Miss. Uganda Prot: 14, 23 & 40 (April 1906) & (desc. expans.) in J.L.S., Bot. 37:506 (Nov. 1906); Z.A.E. 2:422 & t. 47 (1910); I.T.U.: 230 (1940) & ed. 2, with Dale: 407 (1952); Gilbert in F.C.B. 7:66 (1958) pro parte; Hamilton, Uganda For. Trees: 194 (1981); Sands in K.B. 56:20, t. 5, map 1 (2001). Type: Uganda, Toro District, Kibale Forest, Dawe 511 (K!, holo.) Usually evergreen tree 30–45(–50) m high with an irregular, sometimes open crown; trunk up to 1.2 m in diameter, sometimes buttressed and usually very deeply fluted; bark smooth to irregularly rough and warty, yellowish to light brown, sometimes with scattered small black spheres of hardened resinous exudate; branchlets frequently from swollen nodes, often deciduous leaving a conical pit, glabrous or puberulous and glabrescent, yellowish-green occasionally becoming blackened. Spines borne at a wide angle on the trunk and branches, up to 15 cm long and 9 mm diameter at the base, without leaves or flowers, forked or branching several times, the branch-spines subtended by scale-leaves when young; spines on flowering and some sterile branchlets infrequent, usually simple and short, up to 1(–2) cm long borne 5–12 mm above the axil; spinules absent. Leaves on sterile and fertile branchlets, usually persistent; stipules narrowly triangular, 0.2–0.5 mm long, soon caducous; petiole 1–3.1 cm long; petiolules 0.3–1.8 cm long; leaflets ovate to ovate-elliptic with the inner half often slightly smaller than the outer, 5.8–11.5 cm long, 2.7–7.5 cm wide, acute to acuminate, often developing a drip-tip 1.5–3 cm long on sterile shoots, more or less equally rounded or abruptly cuneate, the two sides sometimes joining the petiole 1–2 mm apart, membranous, eventually coriaceous; venation often prominent, glabrous, but sparsely puberulous on the main vein beneath at first; foliole 0.3–3(–14) mm long, sometimes early caducous. Inflorescence 2– 5(–8)-flowered, subfasciculate or condensed, often an umbellate cyme, 0.5–1 cm from the leaf-axil on stems of the current year, or several on an axillary, usually leafless shoot, grey-puberulous to tomentellous; peduncle absent or up to 18 mm long. Flowers 5- merous; sepals elliptic to ovate, remaining concave, 3–6 mm long, 1.5–3.7 mm wide, acute, usually caducous as the bud opens, shortly grey-puberulous to tomentellous outside, the glabrous margin narrow; petals pale yellowish green, oblong-elliptic to oblanceolate, becoming reflexed at anthesis, 6–10 mm long, 1.5–2.5 mm wide, acute, the glabrous tip sometimes slightly contorted, villous within; stamens 10, spreading-erect; anthers 1–1.5 mm long, 0.5–1 mm wide; ovary 1–2 mm high, densely white- to grey- hairy; style 1–1.5 mm long. Fruit only one developing from an inflorescence, soon elongating in early development, brown to yellow at maturity, ovoid or ellipsoid to broadly fusiform, (6.5–)8–12 cm long, (3.5–)5.8–7 cm wide, tapering to obtuse ends, glabrous and dark, pulpy, oily and malodorous within; seed loose at maturity, cream, ellipsoid to fusiform, up to 4.3 cm long. var. wilsoniana; Sands in K.B. 56:25, t. 5/a–k, map 1 (2001) Pedicels up to 1.3 cm long at an thesis. Petals villous within, not exceeding 7 mm long. UGANDA. Bunyoro District: Budongo Forest, 1935, Eggeling 1634! & 15 May 1941, Thomas 3894!; Mengo District: Mabira Forest, Mulange, Jan.–Feb. 1920, Dummer 4396! DISTR. U 2, 4; from Ivory Coast in the west to Uganda and southwards into Congo (Kinshasa) HAB. Moist forest; 1100–1200 m Flora of tropical East Africa 5 NOTES. A var. mayumbensis occurs in Congo (Brazzaville) and Angola, and var. glabripetala in Nigeria. They are distinct in the longer petals and the longer pedicels at anthesis; var glabripetala has glabrous petals.. Many specimens of B. maughamii subsp. acuta from Kenya and Tanzania were formerly identified as B. wilsoniana.