Solanum, L., L.

Knapp, Sandra, Vorontsova, Maria S. & Prohens, Jaime, 2013, Wild Relatives of the Eggplant (Solanum melongena L.: Solanaceae): New Understanding of Species Names in a Complex Group, PLoS ONE 8 (2), pp. 1-12 : 5

Key to the Species of the Eggplant Clade

1a. Fruit with soft pericarp, in a variety of shapes and colours, edible, the mesocarp spongy, usually white or cream, sometimes green or green-tinged; fasciation common, number of flower parts up to 8 and the ovary inflated. Cultivated. S. melongena

1b. Fruit spherical, yellow (sometimes pale orange-yellow) when mature, with comparatively hard pericarp, not palatable, the mesocarp usually green and jelly-like, if slightly spongy less than 1 cm thick; wild plants, flowers 5-merous. 2

2a. Leaves deeply and ornately lobed with primary lobes extending 2/3–3/4 of the distance to the midvein and secondary lobes always present. Southern Africa and around the Mediterranean. S. linnaeanum

2b. Lobes entire or lobed, lobes extending up to 2/3 of the distance to the midvein, secondary lobes usually not present. 3

3a. Leaf lobes obtuse to acute at the tips, sometimes rounded, sometimes with small secondary lobes; lobes J -2/3 of the distance from the leaf outline to the midvein. Leaves and young stems glabrescent to moderately pubescent. 4

3b. Leaf lobes rounded at the tips, sometimes obtuse, never with secondary lobes; lobes up to 1/3(1/2) of the distance from the leaf outline to the midvein. Leaves and young stems usually densely pubescent (hairs overlapping). 6

4a. Calyx lobes on long-styled flowers 7–10 mm long, ovate and leafy, obtuse at the tips. South Africa. S. umtuma

4b. Calyx lobes on long styled flowers 4–7 mm long, deltate or long-triangular with acuminate tips. 5

5a. Calyx lobes on long-styled flowers 4–7 mm long, deltate, ca. 1/6 as long as the fruit at maturity. Continental Africa north of the Equator. S. cerasiferum

5b. Calyx lobes on long-styled flowers 6–7 mm long, longtriangular, 1/2 to 2/3 as long as the fruit at maturity. Cape Verde Islands. S. rigidum

6a. Stems prickly (but see Table 3 ). Prickles straight or slightly curved, usually with broad bases. Corolla on long-styled flowers 1.8–2.5 cm in diameter. Anthers ca. 4.5 mm long. Asia from the Philippines to southeast Asia, India and Madagascar. S. insanum

6b. Stems prickly or smooth. Prickles, if present, curved or straight. Corolla on long-styled flowers 2.5–4.5 cm in diameter. Anthers 5–9 mm long. 7

7a. Leaves usually entire, sometimes lobed. Trichomes on the lower leaf surface sessile or with short stalks to only 0.1 mm long. Fruits 1.5–3 cm diameter. Ubiquitous weed at low altitudes in East Africa. S. campylacanthum

7b. Leaves lobed. Trichomes on the lower leaf surface with stalks to 0.5(1) mm long. Fruits 2.5–4.5 cm diameter. 8

8a. Leaves velvety red-brown on the upper surface. Calyx lobes on long-styled flowers ovate to oblong, leafy, 7–10 mm long. Southern Africa. S. aureitomentosum

8b. Leaves yellow-green to green-brown on the upper surfaces. Calyx lobes on long-styled flowers deltate, 2.5–6 mm long. 9

9a. Leaves concolorous to weakly discolorous, pubescence yellowish. Leaves ca. 1.5 times longer than wide. Young stems (dry specimens) terete to angular; NE Africa and the Middle East to Pakistan. S. incanum

9b. Leaves strongly discolorous, pubescence dirty greenish-brown on the upper surfaces and whitish on the lower surfaces. Leaves 1.5–2.5 times longer than wide. Young stems (dry specimens) with pronounced raised longitudinal ridges. Southern Africa. S. lichtensteinii