Solanum guineense L., Sp. Pl. 184. 1753.

Knapp, Sandra & Vorontsova, Maria S., 2016, A revision of the " African Non-Spiny " Clade of Solanum L. (Solanum sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Lyciosolanum Bitter, Macronesiotes Bitter, and Quadrangulare Bitter: Solanaceae), PhytoKeys 66, pp. 1-142 : 33-35

Solanum guineense L., Sp. Pl. 184. 1753. Figure 7

Solanum sempervirens Mill., Gard. Dict. ed. 8, no. 25. 1768, nom. illeg. superfl. Type. Based on Solanum guineense L.

Atropa solanacea L., Mant. Pl. Alt. 205. 1771. Type. Based on Solanum guineense L.

Solanum aggregatum Jacq., Collectanea [Jacquin] 4: 124. 1791. Type. Based on Atropa solanacea L. (= Solanum guineense L.)

Solanum dasypus Drège ex Dunal, Prodr. [A. P. de Candolle] 13(1): 161. 1852. Type. South Africa. Western Cape: Riebeck’s Castle, Malmesbury Div., J.F. Drège 1933 (holotype: G-DC; isotypes: K, MO [MO-5471839]).

Solanum monticolum Dunal, Prodr. [A. P. de Candolle] 13(1): 161. 1852. Type. South Africa. Western Cape: Piquetberg, Jun 1837 (1838), J.F. Drège s.n. [Lycium 7865] (holotype: G-DC [G00145669]; isotypes: BM [BM001071606], K [K000414167, K000414168], MPU [MPU011277], S [S-11-5670]).

Solanum dasypus E.Mey., Zwei Pflanzengeogr. Docum. ( Drège) 103. 1853, nom. illeg., non Solanum dasypus Dunal, 1852. Type. Based on Solanum dasypus Drège ex Dunal

Solanum dasypodum St.-Lag., Ann. Soc. Bot. Lyon 7: 135. 1880, nom. illeg. superfl. Type. Based on Solanum dasypus Dunal

Solanum bachmannii Dammer, Bot. Jahrb. Syst. 38: 188. 1906. Type. South Africa. Western Cape: Dist. Malmesbury, Darling, Aug 1883, F. Bachmann 599 (type B?, destroyed; no duplicates found).

Solanum aggregatum Jacq. var. bachmannii (Dammer) Bitter, Bot. Jahrb. Syst. 54: 427. 1917. Type. Based on Solanum bachmannii Dammer

Type.

South Africa. "In Guinea", Anonymous s.n. (lectotype, designated by Wijnands 1983, pg. 193: LINN 246.4)

Description.

Lax scrambling many-stemmed shrub to 1 m tall, rhizomatous (?) with extensive underground root system (van Breda 4164). Stems erect or pendent, terete, glabrous to densely and finely pubescent with minute simple uniseriate gland-tipped trichomes, occasionally also with longer simple 4-5 celled uniseriate trichomes to 0.5 mm long; new growth densely glandular pubescent. Bark of older stems pale yellow-green or greenish brown. Sympodial units plurifoliate, the leaves not geminate, clustered on short shoots or less commonly evenly distributed along branches. Leaves simple, 1.5-6 cm long, 0.7-3.3 cm wide, ovate or more rarely elliptic, highly variable in size along single branches, apparently somewhat fleshy, both surfaces glabrous to densely and finely pubescent with gland-tipped simple uniseriate trichomes <0.5 mm long and longer, eglandular simple uniseriate trichomes ca. 0.5 mm long, these denser on the veins abaxially, if the leaves glabrous then at least some gland-tipped trichomes found on margins and abaxial veins; major veins 4-5 pairs, not clearly visible; base truncate to cuneate, only slightly decurrent onto the petiole; margins entire or occasionally with a few shallow lobes, with at least some minute gland-tipped simple trichomes; apex bluntly acute; petioles 0.5-2 cm long, glabrous to densely and finely pubescent, pubescence in parallel with the stems, denser in adaxial groove. Inflorescences arising directly from short shoots that sometimes bear condensed scale-like leaves, with 1-3(5) flowers arising all from the same point on the stem, pubescent like the stems; peduncle absent; pedicels 1.2-2.5 cm long, ca. 1 mm in diameter at the base, ca. 1.1 mm in diameter at the apex, spreading at anthesis, glabrous or finely pubescent with minute simple uniseriate trichomes <0.3 mm long, articulated at the base; pedicel scars closely spaced in what appears to be a fascicle. Buds ovoid, deeply included in the narrowly conical calyx tube, only halfway exserted just before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube 2-4 mm long, narrowly conical, the lobes 1-2.5 mm long, narrowly triangular or somewhat spathulate, the apex rounded, pubescence like that of the pedicels and stems. Corolla 2-5 cm in diameter, 1-2.7 cm long, pale violet or purple-blue to white with a darker purple centre, stellate, lobed less than halfway to the base, the lobes 10-13 mm long, 5-6 mm wide, narrow and tongue-like with rounded, hooded tips, spread ing at anthesis, sparsely pubescent along the lobe midvein adaxially, densely pubescent with minute simple papillae abaxially, these denser on the margins and tips. Stamens equal; filament tube very short, almost absent; free portion of the filaments 2-3.5 mm long, glabrous or sparsely pubescent at the base; anthers 5-5.5 mm long, 1.5-2.5 mm wide, ellipsoid, connivent or slightly spreading, bright yellow, smooth abaxially, the base somewhat sagittate, poricidal at the tips, the pores lengthening to slits with age. Ovary globose, glabrous; style 1-1.2 cm long, glabrous; stigma clavate or capitate, the surface minutely papillose. Fruit a globose berry, ca. 1.5 cm in diameter, reddish orange when mature, the pericarp apparently thin and somewhat shiny; fruiting pedicels ca. 2.5 cm long, ca. 1.5 mm in diameter at the base, pendent or spreading; fruiting calyx lobes appressed and covering the lower third to half of the berry. Seeds 5-10 per berry, ca. 3 mm long, ca. 2.5 mm wide, ovoid reniform, brownish red, the surfaces shallowly pitted, the testal cells sinuate in outline.

Distribution

(Figure 8 ). Endemic to the Cape Region of South Africa.

Ecology and habitat.

Dunes and strand vegetation near the sea, from sea level to 100 m elevation.

Common names and uses.

South Africa: coastal nightshade.

Preliminary conservation status

( IUCN 2014). Least Concern (LC). EOO 89,953 km2 (LC), AOO 24 km2 (EN). Solanum guineense has a relatively wide range in South Africa, and our calculated AOO indicating conservation concern is likely due to the number of specimems we have examined for this study. The species occurs in protected areas around the Cape, and although not weedy, appears to be common, judging from the photographic records in the online community nature recording site iSpot (http://www.ispotnature.org/communities/southern-africa).

Discussion.

Solanum guineense is a distinctive species, with sessile inflorescences bearing only a few flowers with campanulate to spreading corolla lobes, fleshy leaves and bright orange fleshy berries (Fig. 7 ). The only other species with which it could be confused is the sympatric and vegetatively somewhat similar Solanum africanum , with branched inflorescences with more, smaller flowers and blackish purple berries. Solanum africanum has a winged stem and rhomboid leaves, while Solanum guineense has a rounded stem and oblanceolate or obovoid leaves. Solanum guineense was long known by the later name Solanum aggregatum ; it was only in the 1950s that the correct name for this South African taxon began to be used ( Heine 1960). The name Solanum guineense (L.) Mill. is still occasionally used for the Morelloid clade species correctly called Solanum scabrum Mill., the Garden Huckleberry ( Edmonds 2012), and is based on the basionym Solanum nigrum var. guineense L.

In describing Solanum guineense , Linnaeus apparently copied the locality “Guinea” from Boerhaave (1720). Heine (1960) suggested that Linnaeus used the locality pertaining to Solanum nigrum var. guineense L. rather than to Boerhaave’s " Solanum africanum lignosum, folio atroviridi angusto oblong obtuso" ( Boerhaave 1720). He then later tried to correct his mistake ( Linneaus 1771) by transferring this morphologically unusual species to the genus Atropa L. as Atropa solanacea L. Bitter (1917) then used the later name Solanum aggregatum for this taxon, and also as the basis for his subgenus Lyciosolanum .

The unusual few-flowered inflorescences and flowers with petals that only spread at the tips (or at least when dry looking somewhat campanulate) led Bitter (1917) to erect subgenus Lyciosolanum . Seithe (1962) and subsequent authors ( D’Arcy 1972) followed this until molecular data showed Solanum guineense was nested within the paraphyletic “non-spiny” grade of the larger monophyletic Solanum ( Bohs 2005).

In describing Solanum sempervirens , Philip Miller (1768) cited the Linnaean polynomial for Solanum guineense but with a word left out (" Solanum caule inerme fruticoso, foliis [ovatis] integerrrimis, pedunculis lateralibus filiformibus"). He obviously did not know the species from live plants; he does not describe it in English as he did other species in the work. We think he was equating his Solanum sempervirens with the plant named Solanum guineense with the same polynomial in Linnaeus (1753) and consider the names homotypic.

Solanum aggregatum was described from material cultivated in Vienna ( Jacquin 1791). We have found no original material, but Atropa solanacea is cited in the protologue making this name homotypic with it (and with Solanum guineense ).

Dunal used two specimens collected by J.F. Drège as the basis for his Solanum dasypus ( Drège s.n.) and Solanum monticolum ( Drège "Lycium 7865 "). They represent leaf shape variants of Solanum guineense , and the label "Lycium 7865" indicates the difficulties collectors had identifying this as a species of Solanum .

No original material has been found for Solanum bachmannii , but we are accepting Bitter’s (1917) placement of it as a variant of what he called Solanum aggregatum . Dammer (1906) differentiated his new species from Solanum aggregatum by its thicker leaves and 4-merous flowers.

Specimens examined.

South Africa. Eastern Cape: Coernie River, near Enon, Uitenhage Div., Baur 153 (K); near Graaf Reinet , 1866, Bolus 51 (BM, K, S); along the Sunday River near Monkey Ford , Burchell 2885 (G-DC, K, LE); Uitenhage , Redhouse , May 1912, Rogers s.n. (BM); in the forests of Adow, and on the banks of the Zwartkop River , district of Uitenhage, Zeyher 508 (BM, K, NY) . Northern Cape: Garies , 9 miles NNW of Garies, 24 Sep 1948, Acocks 14946 (K, S) . Western Cape: Stikland, between Strand and Pearl Roads, Jul 1932, Acocks 403 (S); Kanonberg, S spur, overlooking Bottelary Road, 1 Jul 1933, Acocks 2767 (S); above Victoria Road between Camps Bay and Clifton, 22 May 1935, Acocks 4561 (S); Nortier Reserve, ca. 8 km N of Lambert’s Bay, 10 Jul 1970, van Breda 4164 (K); Cape of Good Hope, Cap. Bona Spei (S sheet - 'Tafelberg [ Table Mountain ]), Drège 178 (BM, E, LE, S); Kalk Bay Mountains , at summit R, 7 Apr 1934, Galpin 12630 (K); Van Rhyns Pass, near top just below TMS system, 15 Oct 1976, Goldblatt 4326 (K, S); between Hout Bay and Chapman’s Peak, 27 Jun 1945, Leighton 987 (NY); Paarlberg, 24 Apr 1962, van den Merwe 996 (K); Atties Bed, (Percy Sladen Memorial Expedition to the Orange River 1910-1911), 1 Dec 1910, Pillans 5436 (K); Stellenbosch, 20 Aug 1846, Prior s.n. (K); Camp's Bay , 11 May 1847, Prior s.n. (K); Piquetberg [Terra Capensis], 24 Jun 1896, Schlechter 7896 (G x2, K, LE); Klippies Baai, 3419 Caledon AD, Voelklip, Hermanus, 9 Mar 1980, Williams 192 (K); Kliphuewel, Farm Spieka SE of Klipheuwel, 15 Sep 1982, van Zyl 3136 (K) .

Figures

Figure 7. Solanum guineense L. Plate 323 from Icones Plantarum Rariorum vol. 2 (Jacquin 1792 / 1793, as Solanum aggregatum Jacq.), for dates of publication of Jacquin's Icones see Schubert (1945). Reproduced with permission of the Natural History Museum Library.

Figure 8. Distribution of Solanum guineense L.