Solanum lasiocarpum Dunal, Hist. Nat. Solanum 222. 1813.

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

23. Solanum lasiocarpum Dunal, Hist. Nat. Solanum 222. 1813.

Figs 1C , 2A , 39

Solanum indicum L., Sp. Pl. 187. 1753. nom. utique rej. Type. Sri Lanka. Sin. loc., "Habitat in India utraque", Anonymous s.n. (lectotype, designated by Hepper 1978, pg. 555: Herb. Hermann 3: 16, No. 94 [BM000594658]).

Solanum hirsutum Roxb. ex Wall., Fl. Ind. (Carey & Wallich ed.) 2: 253. 1824, nom. illeg., not Solanum hirsutum Dunal, 1813. Type. probably based on Solanum lasiocarpum Dunal.

Solanum quadriloculare Spreng., Syst. Veg., ed. 16 [Sprengel] 4(2, Cur. Post.): 72. 1827. Type. based on Solanum Solanum hirsutum Roxb. ex Wall.

Solanum zeylanicum Blanco, Fl. Filip. [F.M. Blanco] 136. 1837, nom. illeg., non Solanum zeylanicum Scop., 1786. Type. Philippines (no specimens or illustrations cited; no specimens extant). Philippines. Luzon, Benguet province, May 1914, E.D. Merrill [Species Blancoanae] 465 (neotype, designated here: A [00230113]; isoneotypes: CAL [acc. # 316470], K [K000195921], P [P00369171]).

Solanum lasiocarpum Dunal var. velutinum Dunal, Prodr. [A. P. de Candolle] 13(1): 253. 1852. Type. Philippines. Sin. loc., 1841, H. Cuming 690 (lectotype, designated here: P [P00379526]; isolectotypes: BM [BM000886159], K [K000195954, K000195955], G [G00301654], P [P00379525]).

Solanum ferox L. var. lasiocarpum (Dunal) Miq., Fl. Ned. Ind. 2: 647. 1857. Type. Based on Solanum lasiocarpum Dunal.

Solanum lasiocarpum Dunal var. domesticum Heiser, Solanaceae: Biol. & Syst. (ed. D’Arcy) 413. 1986. Type. Cultivated in the Indiana University greenhouses from seeds of "fruits purchased in market in Bangkok, Thailand, Sept. 1, 1980" [collection date mistakenly as "September 21, 1980" in the protologue], 30 Jun 1981, C.B. Heiser 8008 (holotype: IND [IND-1000065]).

Type.

India. Sin. loc. (lectotype, designated by Whalen et al. 1981, pg. 100: [illustration] Rheede von tot Draakestein, Hort. Malab. 2: tab. 35, " Ana-Schunda ". 1680) .

Description.

Shrub to 2 m tall, often heavily armed. Stems erect to spreading, terete, unarmed or sparsely to moderately prickly and stellate-pubescent; prickles to 0.5-1 cm long, broad-based, deltate to narrowly deltate, laterally compressed, very variable in size on a single stem; trichomes porrect-stellate, mixture of sessile and variously stalked, the stalks multiseriate, to 2.5 mm long, the rays 5-8, 0.4-1.5 mm long, the midpoints variable in length, shorter or longer than the rays; new growth densely pubescent; bark of older stems brownish, moderately to sparsely prickly and stellate-pubescent. Sympodial units difoliate, the leaves geminate, the leaves of a pair equal in size and shape or the minor leaf slightly smaller. Leaves simple, shallowly lobed, the blades 20-35 cm long, 15-30 cm wide, ca. 1-1.5 times longer than wide, broadly ovate to ovate, chartaceous, discolorous, armed with prickles similar to those of the stem, these scattered along the midrib and principal lateral veins, often dark-purplished tinged; adaxial surface felty, densely stellate pubescent with porrect sessile trichomes, the rays 2-5, 0.1-0.5 mm long, the midpoints to 2.5 mm long; abaxial surface felty, densely stellate pubescent and farinaceous in appearance, with porrect trichomes like those of the adaxial surface but with longer stalks, the stalks to 2 mm long; principal veins 5-7 pairs, often drying yellowish abaxially; base truncate or obtuse; margins shallowly to moderately lobed, the lobes 3-6 on each side, occasionally somewhat dentate, 1.6-4 cm long, 3-5 cm wide, deltate to broadly deltate, acute or rounded at the tips, the sinuses less than halfway to the midrib; apex acute; petioles 3-14 cm, 1/5-1/2 the length of the blades, densely stellate-pubescent, unarmed or with a few to many prickles like those of the stems, the pubescence with a mixture of stipitate and sessile porrect-trichomes like those of the stem. Inflorescences 0.4-0.9 cm, extra-axillary, often very close to a leaf pair, unbranched, with 6-16 flowers, only one or two open at a time, densely stellate-pubescent, frequently prickly, the prickles like those of the stems; peduncle 0.1-0.4 cm, unarmed or with a few prickles; pedicels 4-9 mm long, 1-1.5 mm in diameter at the base, 1.5-2 mm in diameter at the apex, spreading or somewhat reflexed at anthesis, densely stellate-pubescent like the inflorescence axes, unarmed or with a few prickles, articulated at the base; pedicel scars 0.25-1.25 mm apart. Buds ovoid, the corolla enclosed within the calyx lobes and tube until just before anthesis. Flowers 5-merous, heterostylous and the plants andromonoecious, with the lowermost flower long-styled and hermaphrodite, the distal flowers short-styled and staminate. Calyx with the tube 2.5-4.5 mm long, broadly campanulate, the lobes 3-5 mm long, 2.5-5 mm wide, deltate to broadly deltate, apically acute, unarmed and densely stellate-pubescent with porrect-stellate trichomes like those of the pedicels but the midpoints usually somewhat longer. Corolla 2.5-3.5 cm in diameter, white, stellate, lobed 1/2-3/4 of the way to the base, interpetalar tissue absent, the lobes 6-9 long, 3-6 mm wide, broadly ovate, spreading at anthesis, the tips somewhat reflexed, glabrous adaxially, densely stellate-pubescent abaxially with porrect-stellate trichomes where exposed in bud. Stamens equal or slightly unequal; filament tube minute; free portion of the filaments 0.1-0.2 mm long, glabrous; anthers 6-8.5 mm long, 1.5-2.2 mm wide, strongly tapering, connivant but the tips somewhat spreading, yellow, glabrous, poricidal at the tips, the pores directed distally, not elongating to slits with drying. Ovary conical, pubescent, the hairs appearing simple but with poorly developed and very short rays at the base; style of long-styled flowers 5-10 mm long, glabrous, 1-2 mm long in short-styled flowers; stigma capitate, the surface minutely papillose. Fruits a globose berry, 1-5 per inflorescence, 2.5-3.5 cm in diameter, orange when ripe, the pericarp thin, densely stellate pubescent with sessile porrect-trichomes, the rays 5-15, 0.1-0.4 mm long, the midpoints always longer than the rays, 1.5-4 mm long; fruiting pedicels 1-1.5 cm long, ca. 2.5 mm in diameter at the base, ca. 4 mm in diameter at the apex, woody, spreading or deflexed from weight of the berry; fruiting calyx not markedly accrescent, the lobes only slightly lengthening in fruit and often breaking off, usually unarmed. Seeds 100-200+, 2.2-3.5 mm long, 1.75-2.5 mm wide, flattened reniform, tan, the surfaces minutely pitted, the testal cells with sinuate margins. Chromosome number: n = 12 ( Whalen et al. 1981; Madhavaian 196814, as Solanum ferox L.).

Distribution

(Fig. 40 ). Solanum lasiocarpum is a commonly cultivated plant and occurs from tropical India east through Indochina, extreme southern China, Malaysia and Indonesia to the Philippines and the island of New Guinea.

Ecology and habitat.

Solanum lasiocarpum grows in forest openings, disturbed sites and second growth thickets, from sea level to 1,000 m elevation. Widely cultivated in the region for its fruit.

Common names and uses.

Unless otherwise indicated, common names are from Whalen et al. (1981: 103); languages when recorded are in square brackets. Brunei Darussalam: tarang asai, tarung bawi (Bernstein 133); China: mo ke shue (Tsang 16102); India: ram-begun [Bengali]; Kerala vellathu-vazhuthana ( Mohanan and Henry 1994, as. S. ferox ). Indonesia. Maluku: tomate hutan (Nooteboom 5837), trong baguri (Robinson 286); Sumatra: lattoeeng (many collections), terong hutan ( Lörzing 15014), sontoman (si Toroes 2848); Laos: chou pout din (Vidal 5438), gim ông (Vidal 5438); Malaysia (general): tar-ong-asam [Malay]; Sabah: tarong sulok [Kadayan] (Abdul 2854), terong pipit or terong pasai (Cuadra A-2160), tokung [Sungei] (Cuadra A-1169); Malaysia/Singapore: tĕrong asam ( Burkill 1935); Philippines: basula [Ibang], dabatung [Sulu], tagtum [Panay-Bisaya], tarong-ayam [Bikol], tarong-tarong [Samar-Bisaya, Tagalog], talong gubat [Tagalog] ( Blanco 1837: 136); Sri Lanka: mala-batu [Sinhalese]; Taiwan: da hugno teg io (Henry 358);Timor Leste: kaubasu (Wiriadianata 428); Thailand: ma ûk muak ( Burkill 1935), ma uek ( Heiser 1986), makhua-puu, ma-puu, mauek, yang-khui-dee, bakuek (Widmer 106); Vietnam: cây ca [Annamite] (Poilane s.n.), xo plo xoc [Moi] (Poilane 184). More orthographic and local variants of these names occur throughout the region (see Suppl. material 1 and dataset on the NHM Data Portal, https://doi.org/10.5519/0rqfzvgd).

Solanum lasiocarpum is widely cultivated across its range for its juicy fruits that are used as a base for juices and for cooking, especially in curries ( Heiser 1986). The seeds are burned as used for relief of toothache and in Bangladesh S. lasiocarpum is used as a remedy for coughs, asthma, fever, vomiting, and gonorrhoea ( Lim 2012).

Preliminary conservation status

( IUCN 2019). Least Concern (LC). EOO (6,950,615 km2, LC); AOO (1,032 km2, VU). As a cultivated plant, the true wild distribution of S. lasiocarpum is difficult to assess. As a weedy ruderal species, however, we suggest it is not of immediate conservation concern.

Discussion.

Solanum lasiocarpum , together with S. repandum G.Forst. of the Pacific islands (see Whalen et al. 1981), is one of two non-American members of the otherwise Neotropical Lasiocarpa clade ( Stern et al. 2011) and shares with those species large repand leaves and pubescent berries. Heiser (1987) postulated that S. lasiocarpum was an introduction of the American species S. candidum Lindl. by Spanish mariners. Whalen et al. (1981) suggested that S. lasiocarpum was closely related to and were not "at ease retaining them" as distinct, but did pending further study; they suggested that the distribution of S. lasiocarpum was a puzzling historical problem and was likely not due to recent human introduction. The taxa are indeed morphologically very similar with felty, repand leaves and pubescent fruits, but recent molecular analyses have shown that S. lasiocarpum is in fact more closely related to the Pacific species S. repandum G.Forst. ( Bruneau et al. 1995; Bohs 2004; Aubriot et al. 2016a) and that the morphological similarities are more likely due to convergence.

Cultivated forms of S. lasiocarpum in general lack or have very few prickles, but this character is highly variable. The fruits of S. lasiocarpum are bright orange and have juicy sweet-sour flesh, they are not as large as the fruits of the more commonly cultivated South American species of the Lasiocarpa clade S. quitoense Lam. and S. sessiflorum Dunal, nor of those of the Pacific S. repandum (see Whalen et al. 1981). Solanum lasiocarpum is not as strongly andromonoecious as are species such as S. insanum or S. melongena , and often several of the lowermost flowers are hermaphroditic and develop berries. In other species of the Lasiocarpa clade the expression of andromonoecy is quite labile ( Miller and Diggle 2003; Diggle and Miller 2004), we suspect this is the case for S. lasiocarpum as well.

In many herbaria specimens of S. lasiocarpum and of S. involucratum are annotated as Solanum ferox L., nom utique rej. This confusion is the result of the typification of another suppressed name, S. indicum L. (discussed in detail in Knapp 2011). Miquel (1857) recognised S. involucratum and S. lasiocarpum as varieties of the same taxon (as S. ferox ). Heiser (1996, 2001) used the name S. ferox for S. involucratum , while Whalen et al. (1981) regarded it as ambiguous. Thus, care should be taken with specimens annotated as S. ferox in collections, they could be either S. lasiocarpum (more common in our experience) or S. involucratum . The two species are not closely related; S. involucratum is a member of a clade comprised of S. procumbens , S. expedunculatum Symon and S. leptacanthum Merr. & L.M.Perry (the latter two species from New Guinea), itself apparently related to S. barbisetum and S. praetermissum ( Aubriot et al. 2016a). Solanum lasiocarpum on the other hand has been shown in numerous studies to be a member of the otherwise American Lasiocarpa clade (e.g., Bruneau et al. 1995; Bohs 2004; Stern et al. 2011).

Whalen et al. (1981) did not treat several of the taxa we recognise as synonyms of S. lasiocarpum here, necessitating typification of these names. No herbarium or specimens were cited in Blanco’s (1837) "Flora de Filipinas", and no herbarium is known to exist ( Merrill 1918a, 1923). Merrill (1918a) provided a series of "illustrative specimens" in order to help fix applications of the Blanco’s names, mostly from his series "Merrill: Species Blancoanae". He felt that just because a work was difficult, it should not be ignored, stating "We can no longer look on the work or this or that author, no matter how incomplete or imperfect, as unworthy of consideration, nor can we accept Hooker’s dictum, regarding species proposed by such authors as Blanco, that it was undesirable to devote time to their identification" ( Merrill 1918a: 6). We have selected the duplicate of Merrill’s "illustrative specimen" of S. zeylanicum , Merrill Species Blancoanae 465 at the Arnold Arboretum (A barcode 00230113) as the neotype for this name.

In describing S. lasiocarpum var. velutinum Dunal (1852) cited two collections, one from Macau (Callery s.n. in P) and the other (Cuming 690) from the Philippines. We have selected the best-preserved duplicate of the most widely distributed of these (Cuming 690, P00379526) as the lectotype.

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 1. Diversity of habits and habitats for Solanum subgenus Leptostemonum in tropical Asia A Solanum giganteum, a small tree of the tropical forest understory in India and Sri Lanka (field photograph, unvouchered, India) B S. trilobatum, a scandent species in its typical habitat, along the road in mangrove area (Meeboonya et al. RM 245, Thailand) C S. lasiocarpum, an erect shrub found in disturbed and human inhabited areas where it is often cultivated (Meeboonya et al. RM 272, Thailand) D S. cyanocarphium, a creeper with decumbent stems in forest understory (field photograph, unvouchered, Vietnam) E S. camranhense, a scandent shrub endemic to the coastal dunes of South Vietnam (field photograph, unvouchered, Vietnam) F S. insanum, the wild progenitor of the brinjal eggplant usually found in degraded areas (Meeboonya et al. RM 305, Thailand). Photograph credits: A S. More B, C, F X. Aubriot; D M. Nuraliev E S. Hul.

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 39. Solanum lasiocarpum Dunal A herbarium specimen collected in Thailand in 1910 (Kerr 1236, BM 000886387) B habit (Meeboonya et al. RM 287, Thailand) C detail view of a calyx and a floral bud (Meeboonya et al. RM 272, Thailand) D detail view of an inflorescence with immature fruits (Wang et al. 2063, China) E detail view of a mature fruit (Wang et al. 2063, China). Photograph credits: A CC-BY, © copyright The Trustees of the Natural History Museum, London B, C X. Aubriot D, E S. Knapp.

Figure 40. Distribution of S. lasiocarpum.