Solanum tiinae Barboza & S. Knapp, 2020

Knapp, Sandra, Chiarini, Franco, Cantero, Juan J. & Barboza, Gloria E., 2020, The Morelloid clade of Solanum L. (Solanaceae) in Argentina: nomenclatural changes, three new species and an updated key to all taxa, PhytoKeys 164, pp. 33-66 : 33

Solanum tiinae Barboza & S. Knapp sp. nov. Figs 7 , 8

Diagnosis.

Like Solanum aloysiifolium Dunal but differing in narrower leaves decurrent onto the stems, antrorse pubescence, ellipsoid buds and strongly deflexed fruiting pedicels.

Type.

Argentina. Tucumán: Dtto. Tafí del Valle, El Infiernillo, en el parador, 3042 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 sprawling from a woody base, to 50 cm tall. Stems narrowly winged, the wing to 0.5 mm wide, often invested with spinose processes (enlarged trichome bases), sparsely pubescent with 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, 2-5 cm long, 0.6-2 cm wide, narrowly elliptic to almost lanceolate in some individuals, 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 2.5-5 cm long, opposite the leaves or internodal, forked with 2 short branches, 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 sparsely 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, perfect. 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, 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?), opaque, the pericarp surface thin, matte, 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; 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

(Figure 9 ). Solanum tiinae is endemic to Argentina; it has been collected from the provinces of Jujuy, La Rioja, Salta and Tucumán, with most collections from the area around the type locality at El Infiernillo.

Ecology and habitat.

Solanum tiinae grows among rocks and in open areas in pre-puna habitats in the Andes (Fig. 7A ), from 2400 to 4000 m elevation.

Etymology.

Solanum tiinae is named in honour of our long-term collaborator and colleague Dr. Tiina Särkinen of the Royal Botanic Garden Edinburgh; she was the first to notice the uniqueness of these plants, giving them the field name " Solanum misterioso" while in the field in 2012.

Preliminary conservation status

( IUCN 2019). AOO (76 km2 - EN); EOO (41,143 km2 - NT). 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 is not found in protected areas, and based on the number of localities (ca. 5), the area of occupancy and the extent of occurrence, we assign a preliminary threat status of Vulnerable (VU B2a,biii). Where it occurs S. tiinae is not common or weedy, although it does grow in open areas.

Notes.

It is surprising that S. tiinae has not been described previously, as the area from which the type and many other collections come is one of the most intensively collected Andean areas in Argentina. None of the collections we cite here were cited in Morton (1976). We have encountered specimens of S. tiinae identified as S. aloysiifolium (and its synonyms, see Barboza et al. 2013) and S. cochabambense . It is similar to those taxa 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 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 .

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 strongly antrorse pubescence (Fig. 7B ), the strictly furcate (versus only occasionally once branched) inflorescences with more flowers (10-20 versus 4-10) (Fig. 7B, C ) and the calyx lobes (Fig. 7F ) that are tightly appressed to the berry (versus spreading and slightly recurved). These two taxa have been collected 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, while those of S. tiinae are less deeply and more broadly lobed (Fig. 7E ).

Additional specimens examined

(paratypes). Argentina. Jujuy: Dtto. Tilcara, Sierra de Zenta, 4000 m, Feb 1931, Budin 7471 (CORD). La Rioja: Dtto. Famatina , Rodeo de las Vacas, 3000-4000 m, Feb 1913, Flossdorf 55 (SI); Quebrada Encrucijada, 3500-5000 m, Mar 1913, Flossdorf 56 (SI). Salta: Dtto. San Carlos, Amblayo, 2371 m, 16 Mar 1943, Hunziker 2623 (CORD); Dtto. Cachi, Ruta Prov. 33, de Piedra del Molino a El Carril, La Herradura, 3110 m, 26 Feb 2009, Zuloaga et al. 11256 (CORD, SI). Tucumán: Dtto. Tafí del Valle, Pinar de los Ciervos, Km 70, 2400 m, 6 Mar 1998, Barboza et al. 139 (CORD); Dtto. Tafí del Valle, Pinar de Los Ciervos, km 70, 2400 m, 6 Mar 1998, Barboza et al. 140 (CORD); Dtto. Tafí del Valle, entre Tafì del Valle y Amaichá: Km 76, 6 Mar 1998, Barboza et al. 150 (CORD); Dtto. Tafí del Valle, entre Tafì del Valle y Amaichá: Km 76, 6 Mar 1998, Barboza et al. 151 (CORD); Dtto. Tafí del Valle, entre Tafí del Valle y Amaicha, 6 Mar 1998, Barboza et al. 152 (CORD); Dtto. Tafí del Valle, El Infiernillo, 2920 m, 19 Mar 2006, Barboza et al. 1705 (CORD); Dtto. Tafí del Valle, Carapunco, rumbo a Amaicha del Valle por RP307, 2864 m, 24 Feb 2009, Barboza et al. 2167 (CORD); El Infiernillo, 2960 m, 24 Feb 2009, Barboza et al. 2172 (CORD); Dtto. Tafí del Valle, La Quebradita, a unos pocos km de Tafí del valle rumbo a Amaicha del Valle, 2053 m, 21 Feb 2011, Barboza et al. 3014 (CORD); Dtto. Tafí del Valle, a 28 km de Tafí rumbo a Amaicha del Valle, 2857 m, 21 Feb 2011, Barboza et al. 3019 (CORD); Dtto. Tafí del Valle, desde Amaicha del Valle rumbo a Tafí del Valle, entre km 92-91, 3000 m, 13 Feb 2012, Barboza et al. 3491 (BM, CORD); Dtto. Tafí del Valle, entre Tafì del Valle y Amaichá, El Infiernillo, 19 Feb 1988, Cocucci et al. 293 (CORD); Tafí del Valle, 2500 m, 24 Feb 1998, Cocucci 989 (CORD); Dtto. Tafí del Valle, Km. 82, al N de Tafí del Valle, hacia la quebrada del Barón, 3100 m, 26 Feb 1959, Diers 285 (SI); Dtto. Tafí del Valle, El Molle, en el camino entre Tafí del Valle y Amaicha, km 91-92, 2800-2900 m, 12 Feb 1986, Hunziker et al. 24878 (BM, CORD [x2], E, MO); Dtto. Tafí del Valle, El Molle, en el camino entre Tafí del Valle y Amaicha, km 91-92, 2800-2900 m, 12 Feb 1986, Hunziker et al. 24879 (CORD); Dtto. Tafí del Valle, viniendo desde Tafí del Valle, rumbo a Amaicha del Valle, entre kms 75 y 76, 2600- 2700 m, 14 Dec 1995, Hunziker et al. 25546 (CORD); Dtto. Tafí del Valle, El Infiernillo, 22 km de Tafí del Valle, 2950 m, 18 Mar 1972, Krapovickas et al. 21885 (CTES); Tafí, 2000 m, 4 Dec 1908, Lillo 8691 (CORD, LIL, SI, US); Dtto. Tafí del Valle, La Ciénaga; Sierra de Tucuman, 10 Jan 1874, Lorentz & Niederlein 565 (CORD); Dtto. Tafí del Valle, 16 km N de Tafí del Valle, Mojon, K [km] 78, 16 Mar 1972, Maruñak et al.209 (CTES); Infiernillo, Tafí del Valle, 1850 m, 2 Mar 1972, Meyer s.n. (LIL); Dtto. Tafí del Valle, Ruta 40, ca. 10 km NW de Tafí del Valle, Cumbres Calchaquíes, 2985 m, 26 Jan 2007, Paula-Souza et al. 7912 (CTES); Dtto. Tafí del Valle, Infiernillo, 3040 m, 8 Mar 1955, de la Sota 236 (CORD); Dtto. Tafí del Valle, Cumbres Calchaquí, Quebrada Honda, 3100 m, 23 Jan 1952, Sparre 9232 (CORD); Dtto. Tafí del Valle, Cumbres Calchaquí, Quebrada Honda, 3100 m, 23 Jan 1952, Sparre 9233 (CORD); Dtto. Tafí del Valle, Tafi del Valle, 4 Dec 1960, Subils & Articó 285 (BM, CORD); Dtto. Tafí del Valle, Colalao del Valle, alrededores, 17 Feb 1979, Subils & Bernardello 2670 (CORD); Dtto. Tafí del Valle, pasando Tafí del Valle rumbo a Amaicha, Carapunco, 2942 m, 1 Apr 2012, Urdampilleta et al. 760 (CORD); Dtto. Tafí del Valle, Tafí del Valle, 2900 m, 29 Jul 1971, Without Collector s.n. (BAA); Dtto. Tafí del Valle, El Infiernillo, RP 307, 2995 m, 18 Mar 2018, Zuloaga et al. 16415 (SI).

Figures

Figure 7. Solanum tiinae Barboza & S. Knapp A habit (Barboza et al. 3491) B details of the attenuate leaf base and winged stems with antrorse trichomes (Barboza et al. 3491) C flower bud (Barboza et al. 3496) D inflorescence (Barboza et al. 3491) E flowers at anthesis, note the changing colour and size (Barboza et al. 3491) F mature fruits (Barboza et al. 3491). All photographs by S. Knapp.

Figure 8. Solanum tiinae Barboza & S. Knapp (isotype: Barboza et al. 3496, BM [BM 001115409]).

Figure 9. Distribution of Solanum tiinae Barboza & S. Knapp.