Solanum tiinae Barboza & S.Knapp, PhytoKeys 164: 52. 2020.

Knapp, Sandra, Saerkinen, Tiina & Barboza, Gloria E., 2023, A revision of the South American species of the Morelloid clade (Solanum L., Solanaceae), PhytoKeys 231, pp. 1-342 : 1

56. Solanum tiinae Barboza & S.Knapp, PhytoKeys 164: 52. 2020.

Figs 2D , 169 , 170

Type.

Argentina. Tucumán: Dpto. Tafí del Valle, El Infiernillo , en el parador, 3,042 m, 13 Feb 2012, G.E. Barboza, S. Knapp & T. Särkinen 3496 (holotype: CORD [CORD00013848]; isotypes: BM [BM001115408, BM001115409], others to be distributed) .

Description.

Perennial herbs or subshrubs to 0.5 m high, usually sprawling from a woody base. Stems narrowly winged, the wing to 0.5 mm wide, often invested with spinose processes (enlarged trichome bases), sparsely pubescent with appressed, antrorse eglandular, simple uniseriate trichomes, 6-10-celled, ca. 0.5 mm long, these white when dry; new growth densely to moderately pubescent with antrorse eglandular, simple 2-8-celled uniseriate trichomes, ca. 0.5 mm long; bark of older stems pale greenish brown, glabrescent. Sympodial units plurifoliate, the leaves not geminate. Leaves simple, the blades 2-5 cm long, 0.6-2 cm wide, narrowly elliptic to almost lanceolate in some individuals, widest at the middle, membranous, concolorous; adaxial surfaces sparsely and evenly pubescent with antrorse eglandular simple 2-4-celled uniseriate trichomes to 0.5 mm long, the trichomes slightly longer on the veins, white when dry; abaxial surfaces with similar, but denser eglandular antrorse pubescence; principal veins 4-6 pairs, drying yellow, especially abaxially; base attenuate and decurrent onto the winged stem and the leaves sessile or nearly so; margins entire or with a few teeth ca. 2 mm long, ca. 2 mm wide with blunt tips in the lower third to half; apex acute to slightly blunt-tipped; petiole absent to 0.2 mm long, eglandular pubescent like the stems and leaves. Inflorescences opposite the leaves or internodal, forked with 2 short branches, 2.5-5 cm long, with 10-20 flowers clustered at the tips of the inflorescence branches, sparsely pubescent with antrorse eglandular simple uniseriate trichomes like those of the stems; peduncle 1.2-2.5 cm long; pedicels 0.8-1 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, strongly tapering, spreading to somewhat deflexed at anthesis, sparsely to moderately pubescent with antrorse eglandular simple uniseriate trichomes like the rest of the inflorescence, articulated at the base; pedicel scars clustered at the tips of the inflorescence branches, ca. 0.5 mm apart. Buds ellipsoid to somewhat turbinate (widest in lower third), the corolla strongly exserted from the calyx tube before anthesis, the style sometimes exserted from the bud before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1.5-2 mm long, conical, the lobes (0.5)1-2 mm long, deltate with lanceolate tips, the sinuses rounded, sparsely pubescent with antrorse eglandular trichomes like the pedicels. Corolla 1.2-2.2 cm in diameter, white, pale violet or white tinged with violet, sometimes changing colour through anthesis, with a brownish yellow to yellow-green central star edged with brownish purple, stellate, lobed halfway to the base, the lobes 5-8 mm long, 4-5 mm wide, deltate to triangular, spreading or slightly reflexed at anthesis, adaxially glabrous, abaxially densely pubescent with eglandular papillae and simple uniseriate trichomes to 0.2 mm long. Stamens equal; filament tube minute; free portion of the filaments 0.5-1 mm long, adaxially densely pubescent with tangled transparent simple uniseriate trichomes; anthers 4-5 mm long, 1-1.25 mm wide, ellipsoid, yellow, the abaxial surfaces occasionally papillate, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 7-10 mm long, straight, more or less long-exserted beyond the anther cone, pubescent along almost the entire length, more densely in the lower half with tangled transparent simple trichomes to 0.5 mm long; stigma capitate to clavate, bright green in live plants, the surface minutely papillose. Fruit a globose berry, 0.8-0.9 cm in diameter, green with tiny white spots (immature?), the pericarp thin, matte, opaque, glabrous; fruiting pedicels 0.8-1 cm long, ca. 0.75 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, thickened but not woody, strongly deflexed with a distinct bend at the pedicel base, persistent; fruiting calyx not enlarged or accrescent, the lobes appressed to the surface of the berry. Seeds 10-30 per berry, 1.7-2 mm long, 1-1.5 mm wide, not markedly flattened, teardrop shaped with an apical hilum, pale tan, the surfaces minutely pitted, the testal cells sinuate in outline. Stone cells 4-9 per berry, 0.7-1.5 mm in diameter, 2 usually larger than the rest. Chromosome number: n = 12 ( Moscone 1992, as S. lorentzii Bitter var. montigenum C.V.Morton).

Distribution

(Fig. 171 ). Solanum tiinae is endemic to Argentina (Provs. Jujuy, Salta, Tucumán) with most collections from the area around the type locality at El Infiernillo. The distribution coincides with the Jujuy-Tucumán area of endemism of Aagensen et al. (2012).

Ecology and habitat.

Solanum tiinae grows among rocks and in open areas in pre-puna habitats in the Andes, from 2,400 to 4,000 m elevation.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2022). Near Threatened [NT]. EOO = 40,977 km2 [LC]; AOO = 84 km2 [EN]. Most collections of S. tiinae are from a very few commonly visited localities and the main road between Tafí del Valle and Amaicha del Valle in the Province of Tucumán. Solanum tiinae to date has not been collected in protected areas; based on the number of localities (ca. 5), the area of occupancy and the extent of occurrence it may be of conservation concern. Knapp et al. (2020) assessed it as Vulnerable. Where it occurs S. tiinae is not common or weedy, although it does grow in open areas.

Discussion.

Solanum tiinae is often identified in herbaria as S. aloysiifolium (and its synonyms, see Barboza et al. 2013) or S. cochabambense . It is similar to those species in its forked inflorescence with a long peduncle, but differs from S. aloysiifolium in its larger, less deeply stellate purple or purplish cream (rather than usually white) corollas, and from S. cochabambense in its smaller habit and winged stems. The strongly antrorse pubescence of S. tiinae is distinctive and not found in either S. aloysiifolium or S. cochabambense .

Cabrera (1983) cited specimens of what we recognise as S. tiinae as S. bangii , a synonym of S. gonocladum of high elevation Bolivia and southern Peru. Both these species are subshrubs that are markedly woody at the base with anthers ca. 5 mm long, but S. tiinae differs from S. gonocladum in its deltate calyx lobes with lanceolate tips (versus spathulate in S. gonocladum ), capitate to clavate stigma (versus large capitate in S. gonocladum ) and in its strongly antrorse stem pubescence (versus spreading in S. gonocladum ).

Solanum tiinae also resembles the highly variable species S. salicifolium , from which it can be distinguished by its shorter (1-2 mm versus 2.5-3 mm long) calyx lobes, the appressed strongly antrorse pubescence (Fig. 170B ), the strictly forked (versus only occasionally once-branched) inflorescences with more flowers (10-20 versus 4-10) and the calyx lobes (Fig. 170F ) that are tightly appressed to the berry (versus spreading and slightly recurved in S. salicifolium , Fig. 153C ). These two species have been collected growing side by side in the same habitat (e.g., Barboza et al. 3491, S. tiinae and Barboza et al. 3494, S. salicifolium from km 92 on the Amaicha del Valle to Tafí del Valle road) and can be easily distinguished in the field using corolla shape - those of S. salicifolium are deeply stellate with relatively narrow lobes (Fig. 153D ), while those of S. tiinae are less deeply and more broadly lobed (Fig. 170C ).

Figures

Figure 2. Representative habits and leaves of South American morelloids A prostrate annual herbs (S. weddellii) B large lax shrubs (S. aloysiifolium) C roots forming along a creeping stem (S. juninense) D spinose processes on stems of many species (S. huayavillense) E glandular trichomes found in some members of the clade (S. glandulosipilosum) F dendritic / branched trichomes found in S. pallidum G regularly 3 - lobed leaves in S. palitans H highly variable leaves along a single stem in S. salicifolium (A Saerkinen et al. 4038 B Barboza et al. 3505 C Saerkinen et al. 4754 D Barboza et al. 3536 E Barboza et al. 3520 F Saerkinen et al. 4010 G Atchison & Gagnon 25 H Barboza et al. 3473). Photos by S. Knapp, G. Atchison, and T. Saerkinen.

Figure 153. Solanum salicifolium A habit with less divided leaves B habit with more divided leaves C flowers and buds D flowers at anthesis (A Barboza et al. 3465 B, D Barboza et al. 3494 C Barboza et al. 3473). Photos S. Knapp.

Figure 169. Solanum tiinae A flowering branch B flower bud C flower D calyx E dissected flower F gynoecium G infructescence (A, C-G Barboza et al. 3491 B Barboza et al. 3496). Illustration by S. Montecchiesi.

Figure 170. Solanum tiinae A habit B stem with spinose processes and enlarged trichome bases C inflorescence with flowers and buds D maturing fruits E flower at anthesis F mature and nearly mature berries showing strongly deflexed pedicels (A-F Barboza et al. 3491). Photos by S. Knapp. A-D previously published in Knapp et al. (2020: 53).

Figure 171. Distribution map of Solanum tiinae.