Coccinia megarrhiza C.Jeffrey, Kew Bull. 15(3): 347. 1962.

Holstein, Norbert, 2015, Monograph of Coccinia (Cucurbitaceae), PhytoKeys 54, pp. 1-166 : 91-92

12. Coccinia megarrhiza C.Jeffrey, Kew Bull. 15(3): 347. 1962.

Coccinia megarrhiza Type: Kenya. Northern Province [Eastern Province]: Moyale, 3800 ft, male, fl, 28 Apr 1952, J.B. Gillett 12967 (Holotype: K! [K000313235, digital image: JPS, K], isotypes: B! [B 10 0154926, digital image: B, JPS], S! [S08-12479]).

Coccinia megarrhiza Type: Kenya. Northern Province [North Eastern Province]: [western Mandera District], Dandu, 2600 ft, 10 Apr 1952, J.B. Gillett 12759 (Paratype: K! [K000354130]).

Coccinia megarrhiza Type: Kenya. Northern Province [North Eastern Province]: [western Mandera District], Dandu, 2700 ft, 9 May 1952, J.B. Gillett 13122 (Paratypes: EA!, K! [K000354129]).

Coccinia megarrhiza Type: Kenya. Northern Province [North Eastern Province]: [western Mandera District], Dandu, 3000 ft, 14 May 1952, J.B. Gillett 13191 (Paratypes: EA!, K!).

Coccinia megarrhiza Type: Kenya. Northern Province [Eastern Province]: Moyale, 3200 ft, 3 Oct 1952, J.B. Gillett 13986 (Paratype: K! [K000354128]).

Coccinia megarrhiza Type: Kenya. Northern Province [Eastern Province]: Moyale, 3600 ft, 14 Oct 1952, J.B. Gillett 14036 (Paratypes: B! [B 10 0154927, digital image: B, JPS], BR!, EA!, K! [K000354131], S! [S08-12482]).

Coccinia megarrhiza Type: Kenya. ibid., J.B. Gillett 14037 (Paratypes: BR! [BR0000008914033], K! [K000354133], K! [K000354134], S! [S08-12481]).

Coccinia megarrhiza Type: Kenya. ibid., J.B. Gillett 14038 (Paratypes: K! [K000354125], K! [K000354132]).

Coccinia megarrhiza Type: Kenya. ibid., J.B. Gillett 14039 (Paratypes: K! [K000354126], S! [S08-12480]).

Description.

Perennial climber or creeper. Stem up to 6 m, with long, whitish to beigeish patent trichomes, which appear articulate when dried. Petioles 1.5-5.6 cm, indumentum as on stem (Fig. 9). Leaves 3-11 × 4.2-17 cm, reniform to 3- or 5-lobate. Margin dentate (teeth at maturity brownish, when dried blackening), serrate to lobulate. Upper leaf surface glabrous with pale pustules or with short, whitish to beigeish trichomes, lower leaf surface with indumentum as on stem, rarely glabrous. Probracts up to 3 mm long. Tendrils simple. Male flowers clustered. Pedicel <1.5 cm, indumentum as on stem. Perianth tube with long, beigeish, upright trichomes that appear articulate when dried. Calyx lobes 2.5-4 mm, subulate to lineal, spreading. Corolla 1.2-1.3 cm, yellow to pale orange, lobes 4-6 mm. Filament column greenish, anther head pale greenish, pollen sacs orange-yellow. Female flowers 1(-2) solitary. Hypanthium with long, beigeish, upright trichomes that appear articulate when dried, calyx lobes and corolla like in male flowers. Ovary green with whitish spots. Style columnar, green. Stigma bulging, yellow (Fig. 11c). Fruit ovoid-ellipsoid, up to 6.5 cm long, unripe green with longitudinal white mottling. During ripening mottling partly developing a dark green corona (Fig. 13c). Ripe red (Fig. 12b). Seeds 7 × 4 × 1.5 mm (L/W/H), asymmetrically obovate, face flat.

Phenology.

Flowering time: March-May, August-October.

Distribution.

Fig. 20. Ethiopia (Oromia, Somali Region), Kenya (Eastern Province, North Eastern Province). Elevation 800-1600[-2000] m. On granite outcrops and red lateritic soils, Acacia - Commiphora bushland, Dracaena vegetation, Balanites vegetation, Euphorbia candelabrum woodlands, dry Juniperus forest, grazing is tolerated.

Remarks.

Coccinia megarrhiza and Coccinia abyssinica form a species complex. Distinction between these two species can be difficult, especially in young plants, when the color of the marginal teeth of the leaf is not well developed. While the peduncle length differs, the earlier appearing solitary flowers can have the same length in both species. The broad leaves with an emarginate, obtuse to cuspidate tip ( Coccinia megarrhiza ) versus rather long leaves with an acute tip ( Coccinia abyssinica ) seems to be the best character. At maturity, the teeth coloration in Coccinia megarrhiza is also much more conspicuous than in Coccinia abyssinica . A phylogeographic analysis and crossing experiments would shed light on the question, whether these are ecologically differentiated forms or true species. Plants from the mountains near Yebelo with very large leaves are almost glabrous and occur, untypically, in dry Juniper “forests”. However, they have the typical cuspidate to obtuse central lobes and bear the colored leaf margin teeth. As larger leaves are also observed in high altitude individuals of Coccinia microphylla , these forms might be regarded as mast specimens.

Specimens examined.

(Selection; in total: 29) Ethiopia. Oromia: 38 km S of Neghelli [Negele Boran] on Wachelli road, J.W. Ash 814 (EA (2), K); Arero (Meta-Gafersa), G. Cufodontis 273 (FT, W); Bombal ca. 40 km on the way to Jijiga from Harar, T. Ebba 622 (K, WAG [WAG0285707]); c. 20 km NW of Moyale on the road to Mega, just after the turn off to Tuqa (and Sololo in Kenya) (3°39'N, 38°56'E), I. Friis et al. 8736 (K); c. 36 km from Harar to Jijiga and then c. 20 km to S, J.J.F.E. de Wilde 4793 (B, K, MO, WAG [WAG0285708], WAG [WAG0285709]). Somali Region: 95 km from Negele of Filtu road, 5°00'N, 40°12'E, M.G. Gilbert & B.M.G. Jones 110 (K).