Solanum agnoston S. Knapp, 2013

Knapp, Sandra, 2013, A revision of the Dulcamaroid Clade of Solanum L. (Solanaceae), PhytoKeys 22, pp. 1-432 : 34-37

1. Solanum agnoston S. Knapp sp. nov. Figure 8

Diagnosis.

Differs from Solanum sanchez-vegae S. Knapp in bearing tufts of dendritic trichomes in the vein axils of leaf undersides and elongate, densely pubescent buds; differs from Solanum laxum Spreng. in having shiny upper leaf surfaces, dendritic trichomes rather than simple trichomes in the vein axils of leaf undersides, and densely pubescent buds.

Type.

Ecuador. Loja: km 86 de Saraguro, localidad entre Susudel y el Progreso, 3°20'S, 79°15'W, 5 Aug 1986, J. Jaramillo et al. 8832 (holotype: QCA [QCA183731]; isotypes: MO [MO-5203618], NY [NY00854692]).

Description.

Woody vine or lax shrub, 1-3 m long/tall; stems glabrous, thin and flexuous; new growth glabrous, with a few dendritic trichomes abaxially. Bark of older stems pale greyish brown, glabrous. Sympodial units plurifoliate. Leaves simple, 2-6.5 cm long, 0.8-3.5 cm wide, elliptic to narrowly elliptic, coriaceous or somewhat fleshy, the upper surfaces glabrous and shiny, occasionally with sparse simple uniseriate trichomes to 0.5 mm long along the midvein and the petiole groove, the lower surfaces sparsely pubescent with dendritic trichomes, the trichomes to 0.5 mm long, confined to tufts in the primary vein axils near the midrib; primary veins 3-4 pairs, in the type completely obscured on the upper surface, the midrib yellowish green; base obtuse to truncate; margins entire, sometimes slightly revolute; apex acute; petiole 0.5-1.5 cm long, sparsely pubescent with simple uniseriate trichomes 0.5-1.5 mm long in the groove adaxially, possibly twining. Inflorescences terminal or lateral on short shoots, 2-5 cm long, branched 2-3+ times, with 7-10 flowers, glabrous of with a few dendritic trichomes at the branching points; peduncles ca. 1 cm long or less; pedicels 1-1.2 cm long, <0.5 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, filiform, erect to nodding, glabrous, articulated at the base and inserted into a short sleeve; pedicel scars spaced 0.5-1 cm apart in clusters of 2 or 3. Buds narrowly ellipsoid, the corolla strongly exserted from from calyx before anthesis. Flowers all perfect, 5-merous. Calyx tube 1-1.5 mmm long, conical, the lobes 0.5-1.5 mm long, triangular and keeled, scarious and transparent, glabrous, but with a tuft of simple uniseriate trichomes <0.5 mm long at the apex. Corolla known only from buds, ca. 2 cm in diameter, violet, stellate, lobed ca. 3/4 of the way to the base, the lobes not known from mature flowers, densely pubescent abaxially with weak, simple uniseriate trichomes on exposed bud surfaces, glabrous adaxially. Filaments with the tube ca. 0.5 mm long, the free portions minute, glabrous; anthers ca. 5 mm long, 1-1.5 mm wide, ellipsoid, sagittate at the base, minutely pubescent within between the sutures. Ovary glabrous; style and stigma not seen. Fruit a globose berry, ca. 1 cm in diameter, purple or violet when ripe, the pericarp thin and somewhat shiny; fruiting pedicels 1.8-2 cm long, ca. 1 mm in diameter the base, slightly expanded at the apex, pendent. Seeds ca. 5.5 mm long, 5 mm wide, flattened reniform, pale brown, the surfaces minutely pitted, the testal cells pentagonal in outline. Chromosome number not known.

Etymology.

The specific epithet comes from the Greek “agnostos”, meaning unknown, referring to the paucity of specimens and information on this species.

Distribution

( Figure 9 ). Southern Ecuador in the provinces of Loja and Azuay, between Loja and Cuenca.

Ecology.

Growing in dry scrub and high elevation forests in interAndean valleys at near 3000 m elevation.

Conservation status.

Data deficient (DD); known from only two specimens, assessment not possible.

Discussion.

Solanum agnoston is known from only two localities, both along the main highway from Loja to Cuenca in southern Ecuador. It superficially resembles Solanum laxum , a species of southern Brazil that is widely cultivated in tropical and subtropical environments, but differs from it in the dendritic trichomes of the lower leaf surfaces and the elliptic, pubescent buds. The leaves of the paratype specimen (Holm-Nielson et al. 5115) are thick and very shiny above, such that the venation of the upper surface is not visible; the leaves of Jaramillo et al. 8832 are not as shiny, but match in all other aspects. Label data on both specimens indicate the flowers are violet, but both duplicates of Jaramillo et al. 8832 I have been able to find are in fruit.

Jaramillo et al. 8832 is the only collection of this species with duplicates in Ecuadorian herbaria, and have therefore chosen this specimen as the type so the holotype is in an Ecuadorian institution.

Specimens examined.

Ecuador. Azuay: km 91 of Pan-American Highway N of Loja, 2900 m, 3°25'S, 79°10'W, 5 May 1973, L. Holm-Nielson et al. 5115 (S [S-11-33845]).

Figures

Figure 8. Solanum agnoston S. Knapp. (A, B drawn from Holm-Nielsen et al. 5115 C drawn from Jaramillo et al. 8832). Illustration by Bobbi Angell.

Figure 9. Distribution of Solanum agnoston S. Knapp