Solanum schefferi F.Muell., Descr. Notes Papuan Pl. 1: 44. 1876.

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

40. Solanum schefferi F.Muell., Descr. Notes Papuan Pl. 1: 44. 1876.

Fig. 67

Solanum incanum Scheff., Ann. Jard. Bot. Buitenzorg 1: 39. 1876, nom. illeg., non Solanum incanum L., 1753. Type. Indonesia. West Papua: Andai ( “Andaj”), sin. dat., G. Teijsmann s.n. (lectotype, designated here: BO [acc. # 1324395]; isolectotype: BO [acc. # 1323468]).

Solanum lianoides Elmer, Leaflets Philipp. Bot. 2: 733. 1910. Type. Philippines. MIMAROPA: Luzon, Romblon Province, Sibuyan Island, May 1910, A.D.E. Elmer 10752 (lectotype, designated here: BM [BM000778113]; isolectotypes: A [00077845], BISH [BISH1005079], CAL [acc. # 316476], E [E00273864], F [v0073460F, acc. # 290900], G [G00442946], GH [GH00077844], HBG [HBG511454], K [K000196018], LE [LE00016968, LE00016969], MO [MO-503846, acc. # 3783069], NY [00172284], US [00027651, acc. # 779390]).

Solanum smilacocladum Bitter, Bot. Jahrb. Syst. 55: 79. 1919. Type. Indonesia. Sulawesi: [Sulawesi Utara] "Celebes (Minahassa): Bojong, N. Celebes", 1888, O. Warburg 15072 (lectotype, designated here: NY [00804057]).

Type.

Based on (replacement name for) Solanum incanum Scheff., non L.

Description.

Scrambling shrubs or woody lianas to 10 m long, armed. Stems flexuous, terete, moderately prickly and sparsely to densely stellate-pubescent; prickles 2-4 mm long, 2-2.5 mm wide at the base, strongly recurved (hooked), pale yellowish tan; pubescence of stalked porrect-stellate trichomes, the stalks to 0.5 mm long, multiseriate, the rays 4-8, 0.2-0.4 mm long, the midpoints absent or slightly longer than the rays; new growth moderately to densely stellate-pubescent, the trichomes sessile to short-stalked, the stalks 0.2-0.4 mm, the rays 4-8, 0.2-0.5 mm long, the midpoints ca. 0.4 mm long, equal to the rays; bark of older stems reddish brown and somewhat shiny. Sympodial units unifoliate, the leaves not geminate. Leaves simple, not lobed, the blades 2.5-15 cm long, 1.5-7.5 cm wide, ca. 2 times longer than wide, elliptic-ovate to ovate, widest in the middle or the lower third, chartaceous, somewhat discolorous, armed or unarmed; adaxial surface evenly and sparsely to densely pubescent with mixed sessile and short-stalked porrect-stellate trichomes, the multiseriate stalks to 0.2 mm long and conical, the rays 4-6, 0.1-0.2 mm long, sometimes ascending (pointing upwards from the stalk), the midpoints absent or very short; abaxial surface moderately to densely pubescent with mixed stalked and sessile porrect-stellate trichomes like the adaxial surface, but the pubescence denser, especially along the principal veins; major veins 4-6 pairs, impressed above, densely pubescent especially abaxially; base acute, usually strongly oblique; margins entire; apex acute; petioles 1-1.2 cm long, 1/10-1/5 as long as the leaf blades, densely pubescent with porrect-stellate trichomes like those of the stems, unarmed or armed with 0-5 hooked prickles. Inflorescences 3-10 cm long, internodal and lateral, unbranched or more commonly many times branched, with (2-)10-40 flowers, only a few flowers open at any one time, pubescent with porrect-stellate trichomes like those of the stems, occasionally with a few minute hooked prickles in larger inflorescences; peduncle 0.5-3 cm long; pedicels 0.8-1 cm long, ca. 1 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, spreading, sparsely to moderately stellate-pubescent with porrect-stellate trichomes like the inflorescence axes, articulated above the base leaving a small peg on the inflorescence axis, the pegs 0.5-1 mm long, more glabrous than either the pedicels or the inflorescence axis, drying dark brown to black; pedicel scars irregularly spaced 1-3 mm apart, often raised as short pegs ca. 1 mm long. Buds stout and strongly tapering, strongly exserted from the calyx before anthesis. Flowers 5-merous, heterostylous with the distal flowers on each inflorescence branch short-styled and the plants weakly andromonoecious. Calyx with the tube 2.5-3 mm long, conical, in bud a hyaline cup with darker acumens from the rim, tearing irregularly at anthesis, the lobes 1-2 mm long including the acumens, ca. 1 mm wide, deltate with a subulate tip to 1 mm long, sparsely to moderately stellate-pubescent with porrect-stellate trichomes like those of the pedicels, unarmed. Corolla 2-3 cm in diameter, violet to dark purple, deeply stellate, lobed nearly to the base, interpetalar tissue scarce, but the petal margins thin and somewhat “ruffly”, the lobes 10-14 mm long, 3.5-5 mm wide, spreading at anthesis, mostly glabrous adaxially but in more pubescent individuals with porrect-stellate trichomes on the petal surface, densely stellate-pubescent abaxially with densely tangled stalked porrect-stellate trichomes where exposed in bud, the trichomes with 5-8 rays ca. 0.5 mm long and midpoints equal to the rays, sometimes tinged with purple, the petal margins and tips densely papillate, the tips cucullate. Stamens equal or very slightly unequal; anthers 6-8 mm long, ca. 1.5 mm wide in the lower third, strongly tapering, yellow, poricidal at the tips, the pores directed distally, not elongating to slits with drying; filament tube minute, glabrous; free portion of the filaments ca. 0.5 mm long, glabrous. Ovary conical, sparsely pubescent with simple glandular trichomes and papillae; style in long-styled flowers 9-10 mm long, strongly hooked at the tip, minutely glandular papillate in the lower 1/4, otherwise glabrous, in short-styled flowers ca. 1 mm long, straight, glabrous; stigma slightly lobed, borne on the inner surface of the hooked style tip, the surfaces minutely papillose. Fruit a globose or ovoid berry, 2-3 cm long, ca. 3 cm in diameter (fide Symon 1985: 145; 3-5 cm long fide Elmer 1910: 734), green, the pericarp leathery and shiny, glabrous; fruiting pedicels 1.8-3 cm long, ca. 1 mm in diameter at the base, tapering to an apex ca. 3 mm in diameter, woody, spreading or pendent from weight of berries; fruiting calyx slightly accrescent, the lobes ca. 5 mm long, ca. 2 mm wide, spreading. Seeds more than 100 per berry, ca. 2 mm long, ca. 1.5 mm wide, reddish brown or tan, the surfaces very minutely pitted or smooth, the testal cells not visible. Chromosome number: not known.

Distribution

(Fig. 68 ). Solanum schefferi occurs from the Philippines to northern New Guinea and the Solomon Islands (Malaita Island) to northern Sulawesi and the Malakus in Indonesia.

Ecology and habitat.

Solanum schefferi has been collected growing in open areas near abandoned fields or at forest edges from approximately sea level to 1,500 m elevation. It appears to grow on limestone, a soil type unusual for Solanum .

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2019). Least Concern (LC). EOO (1,012,899 km2, LC); AOO (32 km2, EN). In the area of tropical Asia treated here S. schefferi is at the northwestern part of its range; it is more widely distributed on New Guinea. The small AOO is common in vines of forest canopies, these types of plants are notoriously under-collected but are also often rare where they occur.

Discussion.

Solanum schefferi is a species with most of its distribution on the island of New Guinea, but several collections are from the Malaku islands and northern Sulawesi. Symon (1985) suggested this distribution and its distinct differences from other New Guinea species suggested it was an introduction from the Americas. Molecular phylogenetic study, however, shows that S. schefferi is clearly a member of the Eastern Hemisphere clade of spiny solanums ( Aubriot et al. 2016a) and is member of a small monophyletic group containing S. athenae Symon and S. leptacanthum Merr. & L.M.Perry, both New Guinea endemics (but see below).

Solanum schefferi is a striking species with large, showy (fide Brass 24330) flowers and large fruits. The plants climb with their hooked prickles (like rose thorns) and unlike many other species of New Guinean spiny solanums, the prickles on all parts are hooked. The berries are ovoid when young and grow to a considerable size (fide Elmer 1910: 734; Symon 1985: 145); smaller berries appear to be globose, elongating to ovoid with maturity.

Solanum lianoides has not previously be considered a synonym of S. schefferi ( Symon 1985), but examination of the pubescence and flowers leads us to consider them as belonging to the same taxon. Molecular results of Aubriot et al. (2016a) place S. lianoides in the larger Sahul-Pacific clade and forming a group with S. dunalianum and S. graciliflorum , not closely related to S. schefferi. These results remain to be revisited to ascertain if contamination of one or other of these samples influenced the results. It is clear, however, that S. schefferi is native to tropical Asia, and is not an introduction from the Americas.

The protologue of S. lianoides cites a single collection (Elmer 10752) but does not mention a herbarium ( Elmer 1910). We have selected the only one of the many duplicates of this collection we have seen that has both flowers and fruits (BM000778113) as the lectotype for this name.

In coining the replacement name S. smilacocladum Bitter (1919) cited the same sheets in BO as those used by Scheffer in his description of " S. incanum " ("Herb. Buitenzorg 9853! Sub nom. S. incanum Scheff."), as well as additional syntypes from Berlin (Schlechter 17627, Warburg 15072, Warburg 21246) and Bogor (Koorders 18033B, Koorders 18046B). We have lectotypified S. smilacocladum with Warburg 15072 from northern Sulawesi (NY 00804057), to not make the name homotypic with S. schefferi.

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 67. Solanum schefferi F. Muell. Herbarium specimen collected the Philippines in 1927 (Ramos & Edano 49324, P 00379535). Photograph credit: CC-BY, Museum national d'Histoire naturelle, Paris.

Figure 68. Distribution of S. schefferi.