Solanum putii Kerr ex Barnett, Kew Bull. 16: 485. 1963.

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

36. Solanum putii Kerr ex Barnett, Kew Bull. 16: 485. 1963.

Fig. 61

Type.

Thailand. Prachuap Khiri Khan: Thap Sakae District, Hui Yang [Huai Yang], 6 Oct 1920, Put Phraisurind 3227 (holotype: K [K000922027]; isotypes: BK [257531], BM [BM000886104]) .

Description.

Shrubs of unknown height, unarmed. Stems erect, terete, stellate-pubescent; pubescence of sessile to very short-stalked porrect-stellate trichomes, the rays 4-8, ca. 0.2 mm long, the midpoints absent or to 0.1 mm long, much shorter than the rays; new growth densely stellate-pubescent, the trichomes white and tangled, soon deciduous and the stems glabrate; bark of older stems pale brown. Sympodial units plurifoliate, the leaves not geminate. Leaves simple, the blades 4-10 cm long, 1.5-5 cm wide, ca. 2 times longer than wide, elliptic, widest just below the middle, chartaceous, discolorous, unarmed; adaxial surface evenly and sparsely pubescent with mixed sessile and stalked porrect-stellate trichomes, the stalks to 0.5 mm long, the rays 4-8, to 0.5 mm long, the midpoints absent or to 0.5 mm long; abaxial surface moderately to densely pubescent with mixed stalked and sessile porrect-stellate trichomes, the stalks to 1.5 mm, the rays 8-10, to 0.5 mm long, the midpoints equalling the rays, the lamina clearly visible; major veins 4-5 pairs, densely pubescent especially abaxially; base abruptly truncate, usually strongly oblique; margins entire; apex acute to acuminate; petioles 1-2.5 cm long, ca. 1/4 as long as the leaf blades, unarmed and densely pubescent with weak-rayed porrect-stellate trichomes like those of the stems. Inflorescences 3-7 cm long, internodal and lateral, unbranched, with 10-20 flowers, apparently only a few flowers open at any one time, pubescent with porrect-stellate trichomes like those of the stems; peduncle 1.2-2.5 cm long; pedicels 0.9-1 cm long, ca. 1 mm in diameter at the base, ca. 1.3 mm in diameter at the apex, spreading and perhaps slightly nodding at anthesis, sparsely stellate-pubescent with porrect-stellate trichomes like the inflorescence axes, articulated at the base; pedicel scars evenly spaced 2.5-3 mm apart. Buds tapering, about halfway exserted from the calyx before anthesis. Flowers 5-merous, apparently all perfect (but isotype at BM has a flower dissection that is fasciated with 7 corolla lobes). Calyx with the tube 1.5-2 mm long, conical, the lobes 2-2.5 mm long, ca. 1 mm wide, deltate with a subulate tip to 1 mm long, sparsely stellate-pubescent with porrect-stellate trichomes like those of the pedicels. Corolla ca. 1.6 cm in diameter, white or pale lilac, stellate, lobed ca. halfway to the base, interpetalar tissue scarce, but the petal margins thin and somewhat “ruffly”, the lobes ca. 5 mm long, ca. 5 mm wide, spreading or slightly reflexed at anthesis, mostly glabrous adaxially but with a few stellate trichomes along the petal midveins, densely stellate-pubescent abaxially with densely tangled sessile trichomes where exposed in bud, these densest at the tips. Stamens equal or slightly unequal with 2 slightly longer; filament tube ca. 0.5 mm long, glabrous and papery; free portion of the filaments ca. 1 mm long, glabrous; anthers 4-4.5 mm long, ca. 0.7 mm wide, if unequal, 2 ca. 0.2 mm longer, slightly tapering, yellow, poricidal at the tips, the pores directed distally, not elongating to slits with drying. Ovary conical, glabrous but with a few trichomes at the style base; style 6-6.5 m, glabrous; stigma tiny, a mere broadening of the style apex, the surfaces minutely papillate. Fruit a globose berry, 0.5-0.6 cm in diameter (immature?), colour not known, the pericarp thin and shiny, glabrous; fruiting pedicels 1-1.5 cm long, ca. 1 mm in diameter at the base, tapering to an apex ca. 2 mm in diameter, somewhat woody, spreading; fruiting calyx not accrescent, the lobes often breaking off. Seeds ca. 20 per berry, 2-2.5 mm long, 1.5-2 mm wide, flattened reniform, reddish tan or yellowish brown, the surfaces deeply pitted, the testal cells with sinuate margins. Chromosome number: not known.

Distribution

(Fig. 62 ). Solanum putii is endemic to Thailand and only known from the type collection. A single collection from Vietnam (Nuraliev NUR-1863a) appears to be this taxon, but we include it here with some reservation until further studies are undertaken.

Ecology and habitat.

No habitat notes are recorded on the type gathering of S. putii , but possibly occurs in dry forest.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2019). Data Deficient (DD). Solanum putii is only known from the type collection and little is known about this species otherwise.

Discussion.

Solanum putii is very similar and may be conspecific with S. robinsonii , but we hesitate to synonymise these two taxa until more material is available; the similarities were noted in the original description (notes in packet on holotype at K; Barnett 1963). The leaves of S. putii are more broadly elliptic, more softly pubescent, and less discolorous that those of S. robinsonii ; they are also markedly oblique at the base, while those of S. robinsonii are not. The lamina beneath is clearly visible and the rays on the stellate trichomes are thinner and more delicate. A single dissected flower on the isotype sheet at BM is 7-merous and clearly fascinated, perhaps indicating this is an aberrant plant, a note by Kerr on the holotype at K states "Only flower of Put 3227 examined was abnormal with double ovary, stamens, etc.". The fruit of S. putii are smaller (ca. 0.6 cm in diameter) than those of S. robinsonii (ca. 1 cm in diameter).

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 61. Solanum putii Kerr ex Barnett - Herbarium specimen (holotype) collected in Thailand in 1920 (Put 3227, K 000922027). Photograph credit: © copyright of the Board of Trustees of the Royal Botanic Gardens, Kew.

Figure 62. Distribution of Solanum putii.