Solanum incurvum
Citation:
Fl. Peruv. 2: 34, fig. 154b. 1799.
Type:
Peru, Huánuco: Muña, August, September, Ruiz & Pavón s.n. (lectotype, MA [F neg. 29716, F], designated by Knapp & Helgason, 1997).
Last edited by:
Knapp, S.
Written by:
Knapp, S. & T. Helgason
Habit:
Climbing herb, up to 2 m in length at maturity, often trailing along the forest floor. Stems ca. 8 mm in diameter, minutely to densely pubescent with simple uniseriate trichomes 0.3-1.0 mm long.
Sympodial structure:
Sympodial units unifoliate.
Leaves:
Leaves simple, 6-20 x 3-9 cm, elliptic to ovate, with ca. (5)6-7 pairs of primary veins, glabrous to somewhat densely pubescent with simple uniseriate trichomes, denser along the veins both abaxially and adaxially, the base acuminate, the apex acute; petiole 1.5-9 cm long glabrous to pubescent with simple uniseriate trichomes, glabrate.
Inflorescences:
Inflorescence to 12 cm long, axillary, 1-3 inflorescences per leaf axil, bearing 3-6 open flowers at a time, with up to 12 scars, glabrous to sparsely pubescent with simple uniseriate trichomes. Buds rounded, becoming ellipsoid, strongly exserted from the calyx tube. Pedicels at anthesis 0.8-1.8 cm long, 1-2 mm in diameter, quit soft and lax, pendent, glabrous to sparsely pubescent like the rest of the inflorescence.
Flowers:
Flowers with the calyx tube ca. 0.5 mm long, conical, the sides very strait, the lobes 1-2 x 1-2 mm, acute to slightly obtuse and spreading, glabrous to sparsely pubescent with a few scattered uniseriate trichomes; corolla 12-14 mm in diameter, reddish violet to purple, the tube ca. 2 mm long, the lobes 5-6 mm long, planar to very slightly reflexed, sparsely pubescent abaxially, the tips minutely papillate; anthers 3-4 x 1-1.2 mm; free portion of the filaments minute, the filament tube minute; ovary globose to bottle-shaped, glabrous; style ca. 6 mm long, strait, glabrous; stigma minutely capitate.
Fruits:
Fruit a globose (somewhat conical when immature) berry, 1-1.3 x 1-1.3 cm, green at maturity, drying black, the surface smooth; fruiting pedicel 1-1.5 cm long, nodding.
Seeds:
Seeds ca. 80-100 per fruit, 1-2 mm, flattened-reniform, orange-brown; epidermal cells regular, rectangular, with long hair-like projections, especially at the margins.
Distribution:
Eastern slopes of the Andes from S. Ecuador to S. Peru, montane forest and forest edges, 1540-3000 m.
Phylogeny:
Solanum incurvum is a member of the Solanum ternatum group of section Pteroidea in the Potato clade (Bohs, 2005). Based on morphology (Knapp & Helgason, 1997), S. incurvum is sister to S. ternatum.
References:
Knapp, S. & T. Helgason 1997. A revision of Solanum section Pteroidea Dunal: Solanaceae.
Bull. Nat. Hist. Mus. London, Bot. 27: 31-73.
Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.
Solanum incurvum is one of the most infrequently collected members of section Pteroidea. It grows at the highest elevations, and is apparently not at all common where it occurs. Considerable variation in pubescence exists among the few specimens examined, which is apparently not correlated with elevation or any other discernible ecological factor. This variation in pubescence is common in the group, it occurs also in S. ternatum and S. mite. Like its close relative, S. ternatum, S. incurvum is reported to have lilac flowers, but white flowers also occur.