Citation:
Bot. J. Linn. Soc. 86: 411. 1983.
Type:
Cultivated in Birmingham, England, from plants collected in Bolivia. Santa Cruz: Prov. Valle Grande, 1.5 km from Matoral on road to Valle Grande, top of hill on right side of road, 1400 m, 29 Feb 1980, J.G. Hawkes, J.P. Hjerting & I. Avilés 6496 (holotype, K).
Habit:
Herbs 15-45 cm tall, decumbent to erect. Stems 2-3.5 mm in diameter at base of plant, pale green to pinkish, unwinged, densely invested with short non-glandular trichomes, 120-210 ?m in length, with tetralobulate heads 50-70 ?m in diameter, and longer glandular trichomes, 600-950 ?m in length, with an ovoid gland at the tip, 20-60 ?m in diameter; tubers typically borne singly at the end of each stolon.
Sympodial structure:
Sympodial units tri- to plurifoliate, not geminate.
Leaves:
Leaves odd-pinnate, the blades 11-24 x 5.5-13 cm, green, membranous to chartaceous, densely pubescent adaxially and abaxially with hairs like those of the stems; lateral leaflet pairs 4-6, often subequal except for the most proximal 1-2 pairs that are greatly reduced in size; most distal lateral leaflets 2.4-4.2 x 1.4-1.9 cm, ovate to cordate, the apex acute to obtuse, the base cuneate to truncate to cordate; terminal leaflet 3-6 x 2-2.5 cm, ovate to cordate, the apex acute to obtuse, the base cuneate to truncate to cordate; interjected leaflets typically absent, rarely up to 3, sessile to short petiolulate, ovate to orbicular, petiolules 2-12 mm; petioles 2-5.5 cm, pubescent as the stems. Pseudostipules absent to minute, pubescent with hairs like those of the stem.
Inflorescences:
Inflorescences 3.5-7.3 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 5-7 flowers, with all flowers apparently perfect, the axes densely pubescent with hairs like those of the stem; peduncle 2-3.5 cm long; pedicels 15-22 mm long in flower and fruit, spaced 1-10 mm apart, articulated high in the distal half.
Flowers:
Flowers homostylous, 5-merous. Calyx 4.5-6 mm long, the tube 1-2 mm, the lobes ca. 3 mm, attenuate, the acumens 1.5-2 mm long, with hairs like those of the stem. Corolla 2-2.8 cm in diameter, rotate, white with yellow streaks adaxially and abaxially, the tube 1-2 mm long, the acumens ca. 1 mm long, the corolla edges flat, not folded dorsally, glabrous adaxially, minutely puberulent abaxially, especially along the midribs, ciliate at the margins, especially at the tips of the corollas. Stamens with the filaments 1-2 mm long; anthers 4-6 mm long, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 8-12 mm x ca. 1 mm, exceeding stamens by up to 5.5 mm, straight, glabrous; stigma capitate.
Fruits:
Fruit a globose berry, 1-1.2 cm in diameter, green with dark green stripes when ripe, glabrous.
Seeds:
Seeds from living specimens ovoid and ca. 2 mm long, whitish to greenish in fresh condition and drying brownish, with a thick covering of “hair-like” lateral walls of the testal cells that make the seeds mucilaginous when wet, green-white throughout; testal cells honeycomb-shaped when lateral walls removed by enzyme digestion.
Phenology:
Flowering and fruiting from January to February.
Solanum neocardenasii is a distinctive wild potato species with its relatively narrow leaves with 4-6 pairs of relatively small cordate leaflets. It grows at somewhat low elevations for a wild potato. It is most similar to white-flowered forms of S. berthaultii from Bolivia and Argentina, especially with its dense vestiture of short (Type A) and long (Type B) glandular trichomes, but differs from that species by its generally much smaller leaflets and high pedicel articulation. Unpublished data from nuclear genes shows S. neocardenasii to be a very distinctive species, related to a basal clade of sect. Petota, not to S. berthaultii, which is a member of the clade containing the cultivatedpotatoes.