Flora of Tropical East Africa - Sapindaceae (1998)

Bernard Verdcourt, Frances G.Davies, B. Verdcourt

• Publisher: Routledge
• Year: 2017
• Print ISBN: 9789061913801
• eBook ISBN: 9781351447911
• Topic: Biological Sciences
• Subtopic: Botany
• Index: Biological Sciences

The flora is prepared at Royal Botanic Gardens, Kew, in close collaboration with East African Herbarium and in liaison with the University of Dar es Salaam, the University of Nairobi and the Makerere University. Significant contributions are also made by specialists elsewhere. The flora is designed to a high academic standard and should be a useful resource reference for anyone concerned with the identification and utilization of plants in eastern Africa. Each family is published as a separate part.

FLORA TROPICAL EAST AFRICA

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SAPINDACEAE

F.G. DAVIES & B. VERDCOURT*

Trees, shrubs or rarely herbs, sometimes climbing by tendrils. Indumentum commonly of simple hairs, sometimes in tufts in the axils of leaf-veins, rarely fasciculate; glands of several kinds occurring on both vegetative and flowering parts. Leaves alternate, sometimes crowded (palm-like) at the apex of the tree, variously simple, ternate, biternate, pinnate or bipinnate, in the latter two kinds most often without a terminal leaflet at maturity; stipules lacking or small. Inflorescences axillary or cauliflorous, thyrsoidal, paniculate or racemose. Flowers regular or slightly zygomorphic, unisexual except in some Dodonaea but with non-functional organs of the other sex usually present. Calyx of (3–)4–5(−7) free or partially united imbricate or valvate sepals. Petals absent or 4–5, often with a basal claw, usually with a simple or elaborated scale on the inner face. Disk conspicuous, simple, or rarely a double ring, or reduced to a pair of glands. Stamens 5–20 (−74), often 8, but sometimes variable in number within a species, inserted in most cases inside the disk or occasionally on its surface; filaments free, terete or barely flattened, glabrous or hairy; anthers variously ovoid-sagittate to spherical, sometimes pilose, the connective rarely glandular, dehiscing introrsely by longitudinal slits; pollen grains tricolporate. Ovary 1–8-locular; ovules usually 1–2 (rarely several) per locule; style apical, except in Allophylus where semi-gynobasic, entire or 2–3-lobed. Fruit a capsule, sometimes lobed, or drupe, often composed of one matured mericarp with the aborted remaining carpels visible at its base. Seed usually with a hard black or brown testa, which in one case contains stomata, often with a conspicuous fleshy aril or sarcotesta, without endosperm.

About 147 genera and 2000 species, typically tropical and strongly represented in the American, African and Asian tropical areas; a number of species are cultivated for their edible fleshy fruits.

Radlkofer (E.P. IV, 165: 1–1539 (1931–4)) devoted a lifetime to the monographing of the family. Recently Leenhouts, in preparation for Flora Malesiana, has revised many genera and reappraised the tribes erected by Radlkofer. In 1976 (Muller & Leenh. in The evolutionary significance of the exine) he suggested that Radlkofer’s more primitive tribes, the Sapindeae, Thouineae and Paullineae, are actually the most derived, and the Dodonaeae are not derived but a relict group. In effect this reverses the sequence of Radlkofer, and this is the order adopted here. Leenhouts (1976) further considers that the Aceraceae and Hippocastanaceae are no more than tribes of the Sapindaceae. [This is probably basically correct but these groups are of such horticultural importance I would not wish to tamper with their position – B.V.]

The flowering biology of the Sapindaceae in East Africa is very poorly known and field observations are urgently needed for all genera and species. There are two main classes of sexual arrangement: dioecy, generally constant for a genus (but Allophylus has only some dioecious species) and monoecy. In the latter the tree has mass-flowering of all its inflorescences simultaneously, each inflorescence starting with male flowers which drop off by abscission of the pedicel shortly after anthesis. The next flowers to open are female, which if fertilised remain on the inflorescence, which then reverts to male flowers, sometimes in large numbers and continuing for a long season. However, this sequence may be imperfect through one or more stages being absent in any particular individual in any given season. The sex of the flower bud appears to be determined at least partly by environmental factors and at a late stage, and the sex of an immature inflorescence is impossible to determine in those genera where flowers are morphologically hermaphrodite – more than half those in East Africa. The term staminode is used here for a stamen which fails to dehisce. However, a small percentage of pollen in the staminodes of at least one species has been shown to be fertile.

The structure of the fleshy seed-appendage has been the subject of some disagreements. Van der Pijl (Acta. Bot. Neerl. 6: 608 (1957)) argues that the structure is not homologous with the aril in other families and should be called an ‘arillode’. Corner (The seeds of Dicotyledons, 1976) disagrees and continues to use the term aril, while considering it sarcotestal in origin in some genera. The term aril will be used here regardless of ontogeny. Fruits of several species are quite unknown and should be looked for in the field.

The East African genera belong to the following subfamilies and tribes:

Subfamily Dodonaeoideae (Dyssapindaceae of Radlkofer)

Tribe Dodonaeeae – 1, Dodonaea

Tribe Doratoxyleae – 2, Filicium; 3, Zanha

Tribe Harpullieae – 4, Majidea

Subfamily Sapindoideae (Eusapindaceae of Radlk.)

Tribe Cupanieae – 5, Aporrhiza; 6, Lychnodiscus; 7, Blighia; 8, EHocoelum; 9, Hapbcoelopsis

Tribe Nephelieae – 10, Stadmania; Litchi; Nephelium,; 11, Pappea

Tribe Schleichereae – 12, Macphersonia; 13, Lecaniodiscus; 14, Haplocoelum; 15, Camptolepis

Tribe Melicocceae – Tnstiropsis; Melicoccus

Tribe Lepisantheae – 16, Lepisanthes; 17, Glenniea; 18, Placodiscus; 19, Pancovia; 20, Chytranthus

Tribe Sapindeae – 21, Deinbollia; 22, Sapindus

Tribe Thouinieae – 23, Allophylus

Tribe Paullinieae – 24, Cardiospermum; 25, Paullinia

Several species have been or are cultivated in East Africa, including several well known fruits; all are included in the keys below. Cultivated species belonging to genera dealt within the text will be found there.

Litchi chinensis Sonn, subsp. chinensis (Nephelium litchi Cambess.) (T.T.C.L.: 559 (1949); U.O.P.Z.: 332 (1949)) the lychee (litchee) has been cultivated at Kenya, Kiambu District, Nairobi, Closeburn, Gillett 22754, Kilifi District, 34 km. N. of Mombasa, Vipingo, Bally 8854 and Tanzania, Lushoto District, Amani, Greenway 949 & Magogo 736 & Ngonyani 16 & Furuya 139 and Morogoro, Greenway & Eggeling 8601 and Mengo District, Entebbe (Dale, Introd. Trees Uganda: 48 (1953); also Jex-Blake (Gard. E. Afr., ed. 4: 302 (1957)) mentions that ‘trees grow well and fruit abundantly near Nairobi’). Monoecious evergreen tree to 35 m. Leaflets in 2–4(−5) pairs, elliptic or ± obovate, (3–) 8–11 (−16) cm. long, 1.8–4 cm. wide, mostly acuminate at the apex, cuneate at the base, ± glaucous beneath. Inflorescences 15–30 cm. long with individual cymules 5–12-flowered; flowers yellow. Fruit bright red to purplish when ripe, subglobose, ± 3 cm. long, nearly smooth to densely covered with flat pyramidal acute tubercles up to 1 mm. high. Seeds polished blackish brown, very minutely rugulose, ellipsoid, with slight neck near hilum, ± 1.8–2.5 cm. long, 1.2–1.8 cm. wide, shining, partly or completely enveloped in a pinkish, bluish white or pale yellow juicy aril up to ± 5 mm. thick; hilum circular, 5 mm. diameter, straw-coloured. Morton, Fruits of Warm Climates: 250 (1987) deals with some of the better known cultivars; seedless varieties exist. A full account of the genus is given in Fl. Males., ser. 1,11: 653–658 (1994).

Nephelium lappaceum L. var. lappaceum (T.T.C.L.: 559 (1949); U.O.P.Z.: 377, fig. on 378 (1949)) the rambutan has been grown for its edible fruit at Lushoto District, Amani, Greenway 746; 952; Soleman in A.H. 6184; and Mengo District, Entebbe (Dale, Introd. Trees Uganda: 52 (1953)). Tree 10.5–27 m.; twigs glabrescent to persistently hairy. Leaves 1-foliolate or with 1–7, mostly 5, leaflets; petiole 1.5–12 cm. long; leaflets relatively broad, obovate-oblong, 5–30 cm. long, 2.5–11 cm. wide, obtuse, rounded, truncate to slightly emarginate at the apex or sometimes apiculate to slightly acuminate or rarely distinctly acuminate, mostly widest above the middle, the sides very curved, glabrous above, hairy on midrib or ± all over beneath. Inflorescences axillary or terminal, lax; petals absent. Fruits very variable in colour, crimson, purple, maroon, greenish, yellowish or orange-yellow, ellipsoid to subglobose, (3.5–)6–8 cm. long, 3.5 cm. wide, covered with soft fleshy ± curved, strap-shaped or spine-like appendages 0.5–2 cm. long from tubercles; aril white, tran...

Table of contents

• Cover
• Table of Contents
• FLORA TROPICAL EAST AFRICA
• INDEX TO SAPINDACEAE