Solanum macrocarpon L.

Flora Zambesiaca. Vol. 8, Part 4. Solanaceae. Gonçalves AE. 2005

Morphology General

Erect, often much branched, annual to perennial herb or shrub to 1. 5 m high, armed or rarely unarmed in some cultivars; hairs stellate, long stalked to sessile, long-radiate, sometimes with a long ray and occasionally appearing simple, rarely absent except for a few minute, simple, glandular hairs when young; prickles straw-coloured becoming fuscous upwards, to 18 mm long, straight, subulate from a ± broad base, glabrous

Morphology Reproductive morphology Flowers Calyx

Calyx densely clothed with ± stalked and long-radiate stellate hairs to glabrous, ± prickly or unarmed, in fruit strongly enlarged, appressed to and often enveloping it, very prickly; tube 3–4 cm long, campanulate; lobes foliaceous, 8–15 mm long, elongating to 4 cm in fruit, lanceolate-subulate, sub-acuminate Calyx densely clothed with ± stalked and long-radiate stellate hairs to glabrous, ± prickly or unarmed, in fruit strongly enlarged, appressed to and often enveloping it, very prickly; tube 3–4 cm long, campanulate; lobes foliaceous, 8–15 mm long, elongating to 4 cm in fruit, lanceolate-subulate, sub-acuminate.

Morphology Reproductive morphology Flowers Corolla

Corolla bluish to purple or occasionally white, 1. 6–2.5 cm across, broadly campanulate to rotate-stelliform; lobes broadly triangular, abruptly ending in a short, hairy mucro, densely clothed with long-radiate hairs on the median region outside and with a few stellate hairs on the midrib to quite glabrous inside Corolla bluish to purple or occasionally white, 1.6–2.5 cm across, broadly campanulate to rotate-stelliform; lobes broadly triangular, abruptly ending in a short, hairy mucro, densely clothed with long-radiate hairs on the median region outside and with a few stellate hairs on the midrib to quite glabrous inside.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamen filaments 1–2 mm long; anthers 5–8 mm long, oblong to lanceolate in outline or broadly lanceolate-ellipsoid, emarginate at both ends or cordate basally Stamen filaments 1–2 mm long; anthers 5–8 mm long, oblong to lanceolate in outline or broadly lanceolate-ellipsoid, emarginate at both ends or cordate basally.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 1. 5–2.5 mm in diameter, ± globose, glabrous except for a few sparse, minute, glandular hairs near the top, 4–6-locular.

Morphology Reproductive morphology Flowers Gynoecium Style

Style 7–10 mm long, much shorter in male flowers, ± robust, recurved to the apex, sparsely hairy often with a few uniradiate hairs and also or only with a few glandular ones near the base

Morphology Reproductive morphology Fruits

Fruit ± glossy, at first green-white, later yellow, golden-yellow or orange-yellow, 3–4 cm in diameter or 3–4 × 3.5–4.5 cm, globose or depressed-globose, glabrous, bitter but edible in some cultivars when cooked Fruit ± glossy, at first green-white, later yellow, golden-yellow or orange-yellow, 3–4 cm in diameter or 3–4 × 3.5–4.5 cm, globose or depressed-globose, glabrous, bitter but edible in some cultivars when cooked.

Morphology Reproductive morphology Seeds

Seeds pale yellow-brown or yellowish, 3–4 × 2.5–3 mm, oblique or flattened lenticular, subreniform, conspicuously or minutely reticulate all over Seeds pale yellow-brown or yellowish, 3–4 × 2.5–3 mm, oblique or flattened lenticular, subreniform, conspicuously or minutely reticulate all over.

Note

Chromosome number: 2n=24 Heine, loc. cit. (1963), was of the opinion that S. macrocarpon should probably be regarded as a cultivated glabrous form of the wild S. dasyphyllum, perhaps with hybrid swarms between the two "species". Later Omidiji in Nigerian Agric. J. 13, 1 (1976), referring to the close relationship between them, suggested that they should be conspecific. Then Bukenya in an unpublished M.Sc. thesis (1980), concluded that the two taxa were one only, proposing the name S. macrocarpon; see also Bukenya & Carasco in E. Afr. Agric. For. J. 59: 187–204 (1994). Jaeger, loc. cit. (1985), considered two subspecies within S. macrocarpon sensu lato, subsp. macrocarpon for the cultivated forms and subsp. dasyphyllum for the wild plant, though not recognizing geographical separation or definitive morphological limits between them. J.B. Hall & Bukenya in pers. comm. (fide Jaeger & Hepper in D'Arcy, op. cit: 49 (1986)), studying material from Ghana, concluded that S. macrocarpon should be considered a domesticated form of S. dasyphyllum, both of them intergrading morphologically thus having to be considered conspecific. Recently the same authors in Bothalia, loc. cit. (1987), recognized and described six cultivars and the putative wild ancestor within S. macrocarpon complex, considering the variation displayed attributable to genotypic differences and environmental factors. Taking notice of the several authors cited and considering the unsatisfactory separation of S. macrocarpon from S. dasyphyllum on the basis of the latter being prickly and hairy and the former unarmed and glabrous, I think they should be one species alone under the name S. macrocarpon. See also Lester & Daunay, loc. cit. (2003). Dammer, loc. cit. (1895), recorded S. duplosinuatum from Mozambique N: "Moçambique" and Z: Quelimane Distr., Quelimane. Other Mozambique records not seen by me include Peters s.n., from Nampula Prov. (mainland coast and Moçambique Is.), referred by Klotzsch, loc. cit. (1861) and C.H. Wright, loc. cit. (1906), to S. duplosinuatum, and by Bitter, tom. cit.: 191 (1923), to S. dasyphyllum, and Stuhlmann 136, from Zambezia Prov. (Quelimane), referred also by Bitter, tom. cit.: 191 (1923), to S. dasyphyllum. Binns, loc. cit. (1968), records S. macrocarpon from Malawi, C: Nkhotakota (Nkhota Kota).

Ecology

Evergreen forest edges, floodplains, riverbanks, cultivated ground, in ± dry or sometimes moist situations; up to 1765 m.

Distribution

ZAM B, ZAM W, ZIM N, ZIM C, MAL S, MOZ T, MOZ MS Malawi Widespread throughout tropical and subtropical Africa, recorded from the Canary, S. Tomé, Príncipe and Annobón Islands, from West to East Africa extending northwards to Egypt and southwards throughout East Africa to South Africa (KwaZulu-Natal); also from Zimbabwe Mozambique Zambia

Morphology General Habit

Erect, often much branched, annual to perennial herb or shrub to 1.5 m high, armed or rarely unarmed in some cultivars; hairs stellate, long stalked to sessile, long-radiate, sometimes with a long ray and occasionally appearing simple, rarely absent except for a few minute, simple, glandular hairs when young; prickles straw-coloured becoming fuscous upwards, to 18 mm long, straight, subulate from a ± broad base, glabrous.

Morphology Branches

Branches sometimes dark purple, with dense to sparse indumentum and generally with scattered prickles. Branches sometimes dark purple, with dense to sparse indumentum and generally with scattered prickles

Morphology Leaves

Leaves solitary, sometimes purple tinged, sessile or with a short petiole, occasionally up to 5 cm long; lamina ± membranous, (5)6–35(41) × (2)3–22(25) cm, ovate to obovate, base broadly cuneate to attenuate and ± unequal-sided, long-decurrent into the petiole, but sometimes not decurrent lower down on the branches, apex ± acute, ± deeply sinuate-pinnatifid to sinuate-repand, the lobes ± triangular or ovate-triangular to ± lanceolate, deeply lobulate to entire, rounded or obtuse, rarely acute, the sinuses rounded between the lobes, conspicuously hairy at first, the hairs only persisting above on the midrib and secondary nerves, unequally radiate, setose or lacking, ± dense or scattered beneath, ± long and robustly stalked, finely and pauciradiate, ± prickly mainly on midrib and secondary nerves, more densely so beneath, to quite unarmed. Leaves solitary, sometimes purple tinged, sessile or with a short petiole, occasionally up to 5 cm long; lamina ± membranous, (5)6–35(41) × (2)3–22(25) cm, ovate to obovate, base broadly cuneate to attenuate and ± unequal-sided, long-decurrent into the petiole, but sometimes not decurrent lower down on the branches, apex ± acute, ± deeply sinuate-pinnatifid to sinuate-repand, the lobes ± triangular or ovate-triangular to ± lanceolate, deeply lobulate to entire, rounded or obtuse, rarely acute, the sinuses rounded between the lobes, conspicuously hairy at first, the hairs only persisting above on the midrib and secondary nerves, unequally radiate, setose or lacking, ± dense or scattered beneath, ± long and robustly stalked, finely and pauciradiate, ± prickly mainly on midrib and secondary nerves, more densely so beneath, to quite unarmed

Morphology Reproductive morphology Inflorescences

Cymes lateral, unbranched, sub-umbelliform or racemiform, 2–6-flowered, usually the lowest flower(s) larger and more prickly, sometimes all flowers unarmed, sometimes flowers solitary; peduncle 0–2 cm long, ± prickly to quite unarmed; pedicels 0.5–3 cm long, slender but somewhat stout in fertile flowers, ± prickly or unarmed, erect or ± curved, in fruit elongated to 4 cm, strongly thickened chiefly distally and robust, recurved or deflexed. Cymes lateral, unbranched, sub-umbelliform or racemiform, 2–6-flowered, usually the lowest flower(s) larger and more prickly, sometimes all flowers unarmed, sometimes flowers solitary; peduncle 0–2 cm long, ± prickly to quite unarmed; pedicels 0.5–3 cm long, slender but somewhat stout in fertile flowers, ± prickly or unarmed, erect or ± curved, in fruit elongated to 4 cm, strongly thickened chiefly distally and robust, recurved or deflexed

Morphology Reproductive morphology Flowers

Flowers 5(6)-merous. Flowers 5(6)-merous

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary 1.5–2.5 mm in diameter, ± globose, glabrous except for a few sparse, minute, glandular hairs near the top, 4–6-locular; style 7–10 mm long, much shorter in male flowers, ± robust, recurved to the apex, sparsely hairy often with a few uniradiate hairs and also or only with a few glandular ones near the base.

Cytology

Chromosome number: 2n=24.