Solanum virginianum L., Sp. Pl. 187. 1753.

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

49. Solanum virginianum L., Sp. Pl. 187. 1753.

Figs 2D , 80

Solanum surattense Burm.f., Fl. Ind. (N. L. Burman) 57. 1768. Type. India. Gujarat: “Surat”, L. Garcin s.n. (lectotype, designated by Hepper and Jaeger 1986, pg. 434, as “type”; second step designated here: G-PREL [G00811278]; isolectotype: G-PREL [G00811279]).

Solanum virginicum L., Mant. 2: 340. 1771. Type. Based on (orthographic error for) Solanum virginianum L., not intended as a new name.

Solanum armatum Forssk., Fl. Aegypt.-Arab. 47. 1775. Type. Yemen. Al Hudaydah: Hays, "ad Haes" [from protologue], P. Forsskål s.n. (lectotype, designated here: KIEL [KIEL0005103]).

Solanum xanthocarpum Schrad. & J.C.Wendl., Sert. Hanov. 1: 8, tab. 2. 1795. Type. Based on Solanum virginianum L. (see Hepper and Jaeger 1986).

Solanum jacquinii Willd., Sp. Pl., ed. 4 [Willdenow] 1(2): 1041. 1798, nom. illeg. superfl. Type. Based on Solanum virginianum L. (cited indirectly in synonymy).

Solanum arabicum Dunal, Hist. Nat. Solanum 240. 1813, nom. illeg. superfl. Type. Based on Solanum armatum Forssk. (cited in synonymy).

Solanum xanthocarpum Schrad. & J.C.Wendl. var. schraderi Dunal, Prodr. [A. P. de Candolle] 13(1): 302. 1852. Type. Cultivated in the Calcutta Botanical Garden, "Hort Calc", N. Wallich s.n. [Wallich Catal. 2612b] (lectotype, designated here: G-DC [G00130292]; isolectotypes: BM [BM000900258], K [K001080635], K-W [K001116573]).

Solanum xanthocarpum Schrad. & J.C.Wendl. var. jacquinii (Willd.) Dunal, Prodr. [A. P. de Candolle] 13(1): 303. 1852. Type. Based on Solanum jacquinii Willd.

Solanum mairei H. Lév., Repert. Spec. Nov. Regni Veg. 12: 531. 1913. Type. China. Yunnan: "Plaine de Kiao-Kia", May 1912, E.E. Maire s.n. (lectotype, designated here: E [E00284473]).

Solanum mccannii Santapau, J. Bombay Nat. Hist. Soc. 47: 654. 1948. Type. India. Maharashtra: Pune, “Khandala”, 18 Oct 1943, H. Santapau 2972 (lectotype, designated here: BLAT [acc. # 89719]).

Type.

“America” (lectotype, designated by Hepper and Jaeger 1986, pg. 434: [illustration] " Solanum American. laciniatum spinossimum", Dillenius, Hort. Eltham. 360, t. 267, f. 346. 1732).

Description.

Prostrate shrubs, to 60 cm tall, heavily armed. Stems sprawling to erect, terete, densely prickly and sparsely stellate-pubescent; prickles to 2 cm long, broad-based, straight, straw-yellow in dry material, pale whitish green in live plants; pubescence of sessile porrect-stellate trichomes, the rays 4-7, 0.2-0.5 mm long, the midpoints more or less equal in length to the rays; new growth densely stellate-pubescent with a dense covering of papillose glandular unicellular trichomes, yellowish green or purplish green; bark of older stems brown or purplish brown, glabrescent. Sympodial units difoliate, the leaves not geminate. Leaves simple, deeply lobed, the blades (1-)3-11 cm long, 2-4 cm wide, 1-2.5 times longer than wide, elliptic on outline, membranous to somewhat fleshy, concolorous or slightly discolorous, densely armed on both surfaces along the midrib and major veins with prickles like those of the stems; adaxial surface dark green and shiny, sparsely pubescent with sessile porrect-stellate trichomes, the rays 4-7, 0.2-0.5 mm long, the midpoints longer than the rays, moderately papillose with minute unicellular glandular papillae; abaxial surface lighter and usually more densely stellate-pubescent with trichomes like those of the adaxial surface; major veins 3-6 pairs, drying whitish yellow; base truncate, unevenly oblique with one side basiscopically extended along the petiole; margins deeply lobed, the lobes ca. 20 per side, 1.5-2 cm long, 1-1.5 cm wide, narrowly deltate to triangular, often with secondary lobing, apically acute, the sinuses extending up to halfway to the midrib; apex acute; petiole 1.5-5 cm long, 1/2-3/4 of the leaf blade length, very sparely stellate-pubescent with sessile porrect trichomes, densely prickly with more than 10 prickles like those of the stems. Inflorescences 1.5-7 cm long, internodal or occasionally almost opposite the leaves, usually unbranched, but occasionally forked, with 4-8(-10) flowers, only a few open at any one time, glabrous or with a few scattered porrect-stellate trichomes, moderately prickly with straight, straw-coloured prickles to 1.5 cm long; peduncle 1.4-2.5 cm long, moderately prickly with prickles to 1.5 cm long; pedicels 0.6-0.8(-1) cm long, ca. 1 mm in diameter at the base, 1-1.5 mm in diameter at the apex, erect, glabrous or sparsely pubescent with porrect-stellate trichomes like those of the stems articulated at the base; pedicel scars spaced 0.7-2 cm apart. Buds elongate-ovoid, pointed at the tip, strongly exserted from the calyx tube before anthesis. Flowers 5-merous, heterostylous and the plants weakly andromonoecious, with the lowermost flower(s) long-styled and hermaphrodite, the distal flowers short-styled and staminate. Calyx with the tube 2-3 mm long, cup-shaped, the lobes 2-3 mm long, 1.5-2 mm wide, broadly deltate abruptly narrowing to a slender subulate acumen 1-1.5 mm long, apically acute, densely prickly with prickles to 0.7 cm long, the prickles denser on long-styled flowers, glabrous or sparsely stellate pubescent with porrect trichomes like those of the pedicels. Corolla 2.5-3 cm in diameter, deep violet and fragrant, stellate to almost rotate with abundant interpetalar tissue, lobed 1/4-1/2 of the way to the base, the lobes 0.7-1 cm long, 0.5-0.9 cm wide, broad-deltate, spreading or slightly reflexed, glabrous or sparsely stellate-pubescent along the midveins adaxially, moderately stellate-pubescent abaxially especially on the parts of the corolla exposed in bud and on the tips. Stamens equal; anthers 7-9 mm long, 1.7-2 mm wide, tapering, more or less connivent, bright yellow, glabrous, poricidal at the tips, the pores directed distally, not elongating to slits with age; filament tube minute; free portion of the filaments 0.5-1 mm long, glabrous. Ovary conical, stellate-pubescent with white trichomes that are soon deciduous; style 12-15 mm long and strongly recurved in long-styled flowers, 2-2.5 mm long in short-styled flowers, glabrous or very sparsely pubescent with a few stellate trichomes near the base, the trichomes weak and deciduous; stigma capitate, minutely papillose. Fruit a globose berry, 1-3 per infructescence, 1.5-2.5 cm in diameter, marbled green and white when young, bright yellow when mature, the pericarp thick and leathery, smooth, glabrous; fruiting pedicels 1.2-1.5 cm long, 2-3 mm in diameter at the base, 3-5 mm in diameter at the apex, unarmed or with a few small straight prickles shorter than those of the calyx, thickened and slightly fleshy, strongly recurved, the apical quarter ridged; fruiting calyx lobes elongating to 4 mm long, ca. 1/4 the length of the mature fruit, thickened and slightly fleshy in live plants, appressed to the berry. Seeds 50-100 per berry, 2.5-4 mm long, 2-2.5 mm wide, reniform, not markedly flattened, pale yellowish tan, the surfaces minutely pitted, the testal cells sinuate in outline. Chromosome number: 2n = 24 ( Rajasekaran 1971; Das and Borah 2015, both as S. xanthocarpum ).

Distribution

(Fig. 81 ). Solanum virginianum occurs from the Arabian Peninsula (Saudi Arabia, Yemen) to China and Myanmar.

Ecology and habitat.

Solanum virginianum is a plant of disturbed places, such as roadsides, streambeds and edges of fields, and often occurs in large populations and forms impenetrable mats; from sea level to 3,100 m elevation (highest elevation from Afghanistan).

Common names and uses.

China. mao guo qie ( Zhang et al. 1994). India. Bihar: rengani, kataila ( Varma 1981), as S. surattense ); Haryana: kateli ( Jain et al. 2000, as S. surattense ); Kerala: kandankathiri ( Mohanan and Henry 1994, as S. surattense ); Rajasthan: baiga-kateli, bhurangi, dhaturi [Hindi] ( Singh 1991); Tamil Nadu: kandankathiri [Tamil] ( Matthew 1983); kandangattiri [Tamil] ( Henry et al. 1987).

Solanum virginianum is widely used in medicine as one of the "dasa mulikas" of traditional Indian medicine; used in treatment of asthma, cough, fever etc. ( Tadulingam and Venkatanarayana 1932; Jain et al. 2000). The whole plant is considered highly medicinal ( Singh 1988).

Preliminary conservation status

( IUCN 2019). Least Concern (LC). EOO (7,899,801 km2, LC); AOO (336 km2, EN). Solanum virginianum is a weedy species, forming dense patches in open disturbed areas and along dry riverbeds. Tropical Asia represents the easternmost part of its range.

Discussion.

Solanum virginianum is a seriously mis-named species, Linnaeus (1753: 187) thought it originated in the then-English colony of Virginia ("Habitat in America" - taken from the polynomials cited in synonymy), while in fact it is not found there except as a recent introduction in ships ballast. With its almost glabrous leaves, prominent straw-coloured prickles, large, fragrant purple flowers and weedy habit it is easily recognised and unlikely to be confused with any other species in the region. In the field the flowers of S. virginianum are sweetly fragrant but little is known about the pollination of this, or any other spiny solanum in the region (except S. insanum , see Davidar et al. 2015).

The introduced S. aculeatissimum and S. viarum are similarly prickly, but the prickles are not as long and in those species the leaf pubescence is apparently simple, not stellate. The flowers of both these taxa are white or pale greenish white and the leaves are ovate to broadly elliptic rather than narrowly elliptic in outline.

Solanum virginianum is sister to the main set of African clades of spiny solanums ( Aubriot et al. 2016a), albeit this relationship is only weakly supported and is an isolated lineage; no other species clustered with it in the molecular analyses. Its affinities apparently lie with African rather than tropical Asian lineages such as the 'Sahul-Pacific clade’.

Hepper and Jaeger (1986) inadvertently and effectively lectotypified S. surattense with citation of "Type.: Pakistan, Surat, [....] Garcin in Hb. Burmann " (G-Herb. Delessert!). The Burmann herbarium is held in G-PREL; pre-Linnaean collections were extracted from the general herbarium after 1992, and are no longer part of the Delessert herbarium. Two sheets of Garcin s.n. are housed in G-PREL necessitating a second lectotypification step. We have chosen the more complete of these sheets (G00811278) as the lectotype for S. surattense.

We have lectotypified S. armatum using the only authentic Forsskål material we have found in the Kiel University herbarium (KIEL0005103), although the specimen does not have an indication of the locality.

Solanum jacquinii is an illegitimate superfluous name because S. virginianum was cited in synonymy indirectly by citation of Jacquin’s (1786-1793) illustration, which itself cited Linnaeus. The specimen in the Willdenow herbarium at Berlin (B-W-04384-00 0) bears a copy of Willdenow’s short description on the cover and is certainly that used in the description.

In the description of S. xanthocarpum var. schraderi Dunal (1852) cited a number of names and elements, including S. xanthocarpum itself, suggesting he was considering this the typical variety. We have elected to typify the name however, since the citations are not clear, and choose as the lectotype the G-DC duplicate of Wallich cat. 2618b (G00130292) that is specifically cited in the protologue.

The herbarium of the French botanist and clergyman Augustin A.H. Léveillé was acquired by the Scottish botanist George Forrest from whence it passed to the Royal Botanic Garden Edinburgh. We have selected the specimen at E (E00284473) that corresponds to the description, collector and locality ( Léveillé 1913), as the lectotype for S. mairei .

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 2. Vegetative characters for tropical Asian spiny solanums A large and densely hairy repand leaf of S. lasiocarpum (Meeboonya et al. RM 287, Thailand) B small, pubescent, very shallowly lobed leaf of S. miyakojimense (field photograph, unvouchered, Taiwan) C entire, pubescent leaf of S. robinsonii (Nuraliev 3031, Vietnam) D glabrescent and deeply dissected leaf of S. virginianum (Sampath Kumar et al. 126968, India) E conical straight prickles on a pubescent young stem of S. hovei (field photograph, unvouchered, India) F strongly hooked prickles on a glabrous young stem and on the abaxial leaf surface of S. trilobatum (Meeboonya et al. RM 242, Thailand) G needle-like purple prickles on the adaxial leaf surface of S. cyanocarphium (field photograph, unvouchered, Vietnam) H pubescent young stem of S. barbisetum armed with prickles and bristles (Suksathan et al. PS 3832, Thailand). Photograph credits: A, B, D-F X. Aubriot C, G M. Nuraliev H D. Pedersen.

Figure 80. Solanum virginianum L. A herbarium specimen collected in India in 1958 (Stainton 2306, BM 000900270) B habit (Sampath Kumar et al. 126968, India) C detailed view of a flower (Sampath Kumar et al. 126968, India) D detailed view of immature fruits (Sampath Kumar et al. 126968, India) E detailed view of mature fruits (field photograph, unvouchered, India). Photograph credits: A CC-BY, © copyright The Trustees of the Natural History Museum, London B-D X. Aubriot E S. Knapp.

Figure 81. Distribution of S. virginianum.