Solanum violaceum Ortega, Nov. Pl. Descr. Dec. 56. 1798.

Aubriot, Xavier & Knapp, Sandra, 2022, A revision of the " spiny solanums " of Tropical Asia (Solanum, the Leptostemonum Clade, Solanaceae), PhytoKeys 198, pp. 1-270 : 1

48. Solanum violaceum Ortega, Nov. Pl. Descr. Dec. 56. 1798.

Figs 3A , 78

Solanum chinense Dunal, Hist. Nat. Solanum 240. 1813. Type. China. Sin. loc. (lectotype, designated here: [illustration] Plukenet, Phytographia, pars altera, tab. 62, fig. 1. 1691).

Solanum heynei Roem. & Schult., Syst. Veg., ed. 15 bis [Roemer & Schultes] 4: 669. 1819, as " Heynii ". Type. "H. in India orientali. B. Heyne", B. Heyne s.n. (lectotype, designated by Turner 2021, pg. 418: L [L 0403734]).

Solanum pinnatifidum Roth, Nov. Pl. Sp. 130. 1821, nom. illeg. non S. pinnatifidum Lam., 1794. Type. Based on same material and homotypic with S. heynei Roem. & Schult.

Solanum indicum Nees var. sinuato-lobatum Dunal, Prodr. [A. P. de Candolle] 13(1): 309. 1852. Type. Indonesia. “Malacca”, H. Cuming 2261 (lectotype, designated here: G [G00442779]; isolectotypes: BM [BM000886164, BM000886188], E [E00526948], LE, K [K000014604, K000014606], P [P00055666]).

Solanum indicum Nees var. eroso-pinnatifidum Dunal, Prodr. [A. P. de Candolle] 13(1): 310. 1852. Type. India. Sin. loc., "Bengala inferior", 1817, N. Wallich s.n. [Wallich Catal. 2626e] (lectotype, designated here: G-DC [G00130375]; isolectotypes: GZU [GZU000255428], K-W [K001116646 pro parte, bottom L hand fragment only]).

Solanum indicum Nees var. parvifolium Dunal, Prodr. [A. P. de Candolle] 13(1): 310. 1852. Type. Mauritius. "Isle Maurice", 1839, L. Bouton s.n. (lectotype, designated here: G-DC [G00130374]).

Solanum junghuhnii Miq., Fl. Ned. Ind. 2: 649. 1857. Type. Indonesia. Java: Central Java, "op Tjilatjap" [Cilacap], H. Gesker s.n. [195] (lectotype, designated here: L [L0003638]).

Solanum indicum L. var. inerme Van Heurck & Müll.Arg., Observ. Bot. (Van Heurck) 2: 133. 1871. Type. India. Assam: Sin. loc., W. Griffith 1000 (holotype: BR [AWH10071564]; isotype: BM [BM000900299]).

Solanum pubescens Willd. var. lobatum C.B.Clarke, Fl. Brit. India [J. D. Hooker] 4: 231. 1883. Type. India. Meghalaya: "Assam, Khasi Hills" [Khasia Hills], S. Kurz s.n. (lectotype, designated here: CAL [CAL0000018697]).

Solanum kurzii Brace ex Prain, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 65: 541. 1896. Type. India. Sikkim: Sin. loc., 8 May 1874, G. King s.n. (lectotype, designated here: K [K000441390]).

Solanum indicum L. var. mesarchon Bitter, Repert. Spec. Nov. Regni Veg. Beih. 16: 9. 1923. Type. Mauritius. Pamplemousses District: "Umgebung von Pamplemousse" [surroundings of Pamplemousse], May 1887, S. Paulay s.n. (holotype: W [acc # 1887-0010053]).

Solanum sanitwongsei Craib, Kew Bull. 1928: 246. 1928. Type. Thailand. Bangkok: “cultivated”, 20 Nov 1927, A.F.G. Kerr s.n. (lectotype, designated here: K [K000922035]).

Solanum nivalomontanum C.Y.Wu & S.C.Huang, Acta Phytotax. Sin. 16(2): 74. 1978. Type. China. Yunnan: Fengqing, "Shunning, Snowrange [transl. from the protologue]", 25 May 1938, T.T. Yu 15962 (lectotype, designated here: PE [PE00031398]; isolectotype: KUN [KUN183591], PE [PE00031399]).

Solanum indicum L. forma album C.Y.Wu & S.C.Huang, Fl. Yunnanica 2: 580. 1979. Type. China. Yunnan: Yanshan, "Yan-shan-hsien, Bar-garh [transl. from the protologue]", 16 Nov 1939, C.W. Wang 85018 (lectotype, designated here: PE [PE00031401]; isolectotype: KUN [KUN183578]).

Type.

India. " Habitat en Bahia Botanica. Floret Octobri et Novembri in Reg. Hort. Matrit. è seminibus Londino missis per Exc. D. Marchionissam de Bute " (neotype, designated by Knapp 2013b, pg. 59: MA [ MA307449 ]) .

Description.

Erect shrub, to 3 m tall, armed or unarmed. Stems erect, flattened to terete, prickly or less often unarmed, moderately to densely stellate-pubescent; prickles to 10 mm long, to 7 mm wide at the base, usually curved, sometimes straight, rounded or flattened, straw-yellow to orange-brown, glabrous or sparsely pubescent in the lower 1/3; pubescence of sessile or shortly stalked porrect-stellate trichomes, the stalks less than 0.1 mm long, the rays 6-8, 0.1-0.2 mm long, the midpoints same length as the rays or to 1.5 mm long; new growth densely stellate-pubescent, the trichomes like those of the stems; bark of older stems brown, glabrescent. Sympodial units difoliate, the leaves geminate. Leaves simple, more or less deeply lobed, the blades 4-12 cm long, 2.5-11 cm wide, 1.5-2 times longer than wide, usually ovate in outline, sometimes elliptic, chartaceous, strongly discolorous but sometimes concolorous on dry material, unarmed or with several straight prickles to 10 mm long on veins of both surfaces; adaxial surface evenly and moderately to densely stellate-pubescent with sessile or short-stalked trichomes, the stalks to 0.5 mm, the rays 4-10, ca. 0.5 mm long, the midpoints shorter than the rays or to 2 mm long; abaxial surface densely stellate-pubescent with trichomes like those of the adaxial surface but with longer rays and midpoints, the lamina not usually visible; principal veins 3-5 pairs; base usually truncate, often oblique; margins lobed, the lobes (2-)3(-4) on each side, 1-4.5 cm long, broadly deltate to oblong or obovate, often with secondary lobes, apically obtuse, sometimes acute or rounded, the sinuses extending to 2/3 of the way to the midrib; apex acute; petiole 1-6 cm long, 1/5-3/5 of the leaf blade length, densely stellate-pubescent, unarmed or with a few straight or slightly curved prickles. Inflorescences, 2.5-8(-10) cm long, lateral or leaf-opposed, unbranched or sometimes forked, with 5-15(-30) flowers, 2-3 flowers open at any one time, moderately to densely pubescent with stellate-porrect trichomes like those of the stems, unarmed or with a few straight prickles; peduncle 0.1-1(-2.5) cm long, usually unarmed; pedicels 0.8-1.7 cm long, 0.7-1 mm in diameter at the base, 1.6-2 mm in diameter at the apex, straight and slender, unarmed, densely stellate-pubescent like the inflorescence axes, articulated at the base; pedicel scars spaced 2-10 mm apart. Buds ovoid, the corolla strongly exserted from the calyx before anthesis. Flowers 5-merous, apparently all perfect. Calyx with the tube 1.5-2 mm long, obconical to cup-shaped, the lobes 1.5-4 mm long, 1.5-2.5 mm wide, deltate, apically apiculate to acute, rarely long-acuminate, with no venation visible, unarmed or with up to 10 straight prickles, densely stellate-pubescent with sessile porrect-stellate trichomes like those of the rest of the inflorescence. Corolla 1.3-3 cm in diameter, pale blue to purple or more rarely white, stellate, lobed 1/2-2/3 of the way to the base, the lobes 4.5-8 mm long, 3-5 mm wide, deltate, spreading to slightly reflexed at anthesis, mostly glabrous adaxially, moderately to densely stellate-pubescent abaxially, the trichomes porrect, sessile to shortly stalked, the stalks up to 0.1 mm, the rays 6-8, 0.1-0.2 mm, the midpoints shorter than the rays, but lengthening towards corolla lobe apices. Stamens equal; filament tube minute; free portion of the filaments 0.5-1 mm long, glabrous; anthers 4.5-8.5 mm long, 1.2-1.5 mm wide, yellow-orange or yellow, connivent, tapering, glabrous but sometimes with a few stellate trichomes, poricidal at the tips, the pores directed distally and lengthening to slits with age. Ovary ovoid, glabrous but with a few stellate trichomes towards the apex; style 7-11(15) mm long, filiform, straight to gently curved, stellate-pubescent in the lower 1/3-2/3; stigma clavate to capitate, the surface minutely papillose. Fruit a globose berry, several per infructescence, 0.7-0.9 cm in diameter, yellow to orange when ripe, the pericarp thin and shiny, glabrous; fruiting pedicels 1.2-1.8 cm long, 0.5-1.2 mm wide at the base, 3-3.5 mm in diameter at the apex, somewhat woody, straight, spreading, unarmed or with a few straight prickles; fruiting calyx lobes elongating to 3.5-6(-8) mm long, 1/4-1/2 of the length of the mature fruit, spreading and usually not reflexed, unarmed or with up to 10 straight prickles. Seeds ca. 10-15 per berry, 2.2-3.5 mm long, 1.8-3 mm wide, flattened-reniform, yellow to orange-brown, the surfaces minutely pitted, the testal cells with thick, strongly sinuate margins. Chromosome number: n = 12 ( Karihaloo 1991), 2n = 24 ( Karihaloo 1991; Das and Borah 2015, as S. kurzii ).

Distribution

(Fig. 79 ). Solanum violaceum occurs across Asia, from India to China, Vietnam and Malaysia, from the coasts to inland mountains between ca. 3-27° latitude. It is very common in India, southern China, and Thailand. The westernmost recorded occurrences are on the islands of Mauritius, Réunion and Rodrigues. Chinese populations are restricted to the more southern regions of Fujian, Guangdong, Guangxi, Hainan, Hong Kong, Sichuan Taiwan, and Yunnan ( Zhang et al. 1994). There are occasional collections from Sumatra and Java, but it is not clear whether these are from the wild or cultivated. Solanum violaceum does not occur wild in the Philippines, New Guinea, or Australia.

Ecology and habitat.

Solanum violaceum is usually found growing in open places, abandoned cultivation, and roadsides, in a variety of forest types; between sea level and 2,000 m elevation.

Common names and uses.

China. ci tian qie ( Zhang et al. 1994); Yunnan: xue shan qie (eggplant from the snow mountain; Yu 15962). India. Bihar: jangali baigan ( Varma 1981, as S. indicum ); Goa: ringani, inoti-ringani, badane, dorli (darli), motaring ( Naithani et al. 1997); Karnataka: mullsunde, kad badne, ustikai ( Singh 1988); Kerala: cheruchunda ( Mohanan and Henry 1994, as S. anguivi Lam.); Tamil Nadu: naaimulli, mulluchundai [Tamil] ( Matthew 1983); cherukinda, cheruvazhuthanai [Malayalam], ciruvaludalai, kondal, karimulli [Tamil] ( Nair and Nayar 1987, as S. indicum ), mulli, pappara-mulli, karimulli [Tamil] ( Henry et al. 1987, as S. anguivi ). Malaysia/Singapore: tĕrong pipit puteh, tĕrong pipit hijau ( Burkill 1935), tèrong peuheur [Sundanese] ( Burkill 1935).

The roots of S. violaceum (as S. indicum ) are one of the ingredients of Dashamoola of Ayurvedic medicine used to treat inflammatory conditions of all kinds ( Naithani et al. 1997; Jain et al. 2000). It is regarded as a diuretic, is used for treatment of dropsy, and as an asthma and catarrhal expectorant ( Jain et al. 2000). Unripe fruits are used in the preparation of curries ( Naithani et al. 1997).

Preliminary conservation status

( IUCN 2019). Least Concern (LC). EOO (10,078,363 km2, LC); AOO (988 km2, VU). Solanum violaceum is one of the most widely distributed spiny solanums of tropical Asia and grows in a wide variety of disturbed habitats, often as large populations of individuals.

Discussion.

Solanum violaceum is very widespread and is common where it occurs. In the older literature the name Solanum indicum was often used for this taxon, but considerable confusion over its application led to its suppression ( Hepper 1978; see Doubtful and excluded names).

Solanum violaceum is a plant of disturbed areas, often growing along roadsides and in stream beds. It has been confused with S. anguivi Lam., an African taxon, because of its small orange to red berries and small, hermaphroditic flowers (e.g., Hepper 1978; Singh 1991), but is not directly related to that species. It differs from S. anguivi in its orange, rather than red, berries, its usually violet or pale violet, rather than white flowers, and in its straight, spreading pedicels in fruit, rather than slightly curved pedicels.

In the Flora of Bhutan ( Mill 2001) S. violaceum was treated as S. kurzii (specimens with few prickles) and S. anguivi (prickly plants).

Solanum violaceum is sympatric with its close relatives S. deflexicarpum of southern China, S. hovei , and S. multiflorum , the latter two endemic to India. All of these species have strongly deflexed pedicels in fruit, while those of S. violaceum are broadly spreading and usually longer. See those species descriptions for more details. Solanum violaceum is quite variable across its range in leaf shape and prickliness; populations from Sri Lanka and Thailand lacking prickles have been called S. kurzii and S. sanitwongsei , respectively. Similar unarmed plants, however, are found across the range of S. violaceum and even within populations.

Solanum chinense was described as a species of uncertain status related to S. violaceum ( Dunal 1813) referring only to Tournefort (1700) and an illustration from Plukenet (1691); we have found no other authentic original material, and so lectotypify the name using the Plukenet illustration which matches the protologue.

The varieties of S. indicum sensu Nees described by Dunal (1852), were based on the polynomial varieties from Nees van Esenbeck (1834), which themselves were based entirely on specimens from Wallich’s herbarium that he saw in London ( De Candolle and Radcliffe-Smith 1981). Dunal (1852) cited a number of specimens and concepts in synonymy, making typification difficult, but in lectotypifying these infraspecific names we have used specimens at G-DC that Dunal definitely would have seen during his preparation of the Prodromus treatment. For var. Prodromus sinuatolobatum we have selected as the lectotype a collection specifically mentioned in the protologue "Cuming 2261, hb. Boiss." (G00442779) that is widely duplicated. For var. Solanum pinnatifidum parvifolium we have selected the Bouton s.n. specimen from Mauritius in G-DC cited in the protologue (G00130374) because it is an unambiguous, well-preserved specimen. Var. Solanum pinnatifidum eroso-pinnatifidum cited " S. pinnatifidum Roth, S. heynii R.&S., Solanum indicum Wall. cat. 2626 D,E" as material; we have selected the G-DC specimen of "Wallich cat. 2626E" (G00130375) as the lectotype of this variety. The “duplicate” in the Wallich herbarium at Kew (K00116646) is a mixture of potentially three elements, only the lower L hand stem of which we regard as isolectotype material; this fragment has the letter “E” in pencil, as does the larger R hand fragment. This larger fragment appears to be a collection of S. multiflorum , and so we exclude it as type material for var. Solanum multiflorum eroso-pinnatifidum . Duplicates of all these varieties in Nees van Esenbeck’s own herbarium at GZU all correspond to S. violaceum and are considered isolectotypes.

Miquel (1857) cited three specimens in the protologue of S. junghuhnii : Gesker s.n. from “Tjiltajap”, Junghuhn s.n. from "Awoe Awoe" and Horsfield s.n. from “Soerakarta”. We have selected the Leiden specimen (L 0003638) collected by F.W. Junghuhn as the lectotype, it is labelled unambiguously as to locality and matches the protologue.

Clarke (1883) indicated his uncertainty over the identity of his S. pubescens var. lobatum by stating "Var.? lobata " and "it resembles the unarmed form of S. Melongena but the flowers are too small." He cited a specimen "from Herb. Calcutta, named S. pubescens by Kurz". Several specimens in CAL are so labelled, we have selected the best of these (CAL0000018697) as the lectotype.

The protologue of S. kurzii ( Prain 1896) cites three specimens, two from Sikkim (Thomson s.n. and King s.n.) and one from “Khasia” (Mann s.n.). Specimens collected from the effort towards the flora of British India ( Endersby 2008) are usually un-numbered and have minimal to no locality information. Tracing them can be challenging. A sheet at Kew (K000441390) collected by George King in Sikkim in 1874 matches the protologue in being nearly without prickles and is here selected as the lectotype for S. kurzii .

The protologue of S. santiwongsei cites only an un-numbered collection of A.F.G. Kerr from Bangkok, with no further details. Craib in his many papers of additions to "Siamese plants" never cited herbaria, but in the final compilation of these lists ( Craib 1928) stated that the distributions of all species were taken from specimens at Kew. We have therefore selected a specimen collected by Kerr in Bangkok of a cultivated plant annotated with the name S. sanitwongsei (K000922035), as the lectotype of this name.

The type of S. nivalomontanum is indicated as being in PE ( Wu and Huang 1978), but two duplicates of the type gathering are housed there; we here select the better preserved of these (PE00031398) as the lectotype. The protologue of S. indicum forma album cites a gathering (Wang 85018; Wu and Huang 1979), but no herbarium is mentioned. We have selected the duplicate preserved in PE (PE00031401) as the lectotype, because we have been able to access images of it and ascertain its identity.

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 3. Diversity of inflorescences and flowers in tropical Asian spiny solanums A lax, spreading inflorescences and stellate flowers of Solanum violaceum (Sampath Kumar et al. 126945, India) B condensed, recurved inflorescences and stellate flowers of S. multiflorum (Sampath Kumar et al. 126950, India) C inflorescences and large stellate flowers of S. involucratum (field photograph, unvouchered, Vietnam) D inflorescences and stellate flowers of S. pubescens with unequal stamens, one long and recurved (Sampath Kumar et al. 126956, India) E large rotate flower of S. insanum with abundant interpetalar corolla tissues (Sampath Kumar et al. 126918, India) F many flowered inflorescence and infructescence of S. pseudosaponaceum (field photograph, unvouchered, Philippines) G many flowered inflorescences of S. torvum; flowers with well-developed interpetalar corolla tissues (Suksathan et al. PS 3815, Thailand) H small stellate flowers of S. viarum (Sampath Kumar et al. 126944, India). Photograph credits: A, B, D, E, H X. Aubriot C M. Nuraliev F D. Tandang G D. Pedersen.

Figure 78. Solanum violaceum Ortega A herbarium specimen collected in Thailand in 1920 (Kerr s. n., BM 000886106) B habit (field photograph, unvouchered, Thailand) C detailed view of a white flower with immature fruits (Sampath Kumar et al. 126947, India) D detailed view of a purple flower (field photograph, unvouchered, Thailand) E detail view of an infructescence (Sampath Kumar et al. 126945, India). Photograph credits: A CC-BY, Museum national d'Histoire naturelle, Paris B-E X. Aubriot.

Figure 79. Distribution of S. violaceum.