Herbs 0.4-1.4 m tall, ascending to erect or semi-erect, decumbent or prostrate. Stems 5-19 mm in diameter at base of plant, unwinged or with wings to 5 mm, nearly glabrous to densely pubescent, green or purple to green and purple mottled.
Sympodial units tri- to plurifoliate, not geminate.
Leaves odd-pinnate, the blades 8-22 x 5-13 cm, medium to dark green, membranous to chartaceous, leaf surface dull to shiny, nearly glabrous to densely pubescent adaxially and abaxially, with hairs like those of the stems; lateral leaflet pairs 3-8, only slightly decreasing in size from the apex to the base; most distal lateral leaflets 3-8 x 1.5-5.5 cm, ovate to elliptic to broadly elliptic-lanceolate, the apex acute to acuminate or shortly acuminate, the base generally oblique, rounded to cuneate to cordate, rarely truncate; terminal leaflet 3.5-9 x 1-5.5 cm, ovate to elliptic to broadly elliptic-lanceolate, the apex acute to acuminate or shortly acuminate, the base generally oblique, rounded to cuneate to cordate, rarely truncate; interjected leaflets 0-45, sessile to short petiolulate, ovate to elliptic to broadly elliptic-lanceolate; petioles 2-6 cm, pubescent as the stems. Pseudostipules 4-25 mm long, auriculate to semi-elliptic, falcate, pubescent with hairs like those of the stem.
Inflorescences 5-11 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 0-25 flowers, with all flowers apparently perfect, the axes pubescent with hairs like those of the stem; peduncle 0-22 cm long; pedicels 10-35 mm long in flower and fruit, spaced 1-10 mm apart, articulated in approximately the middle third.
Flowers homostylous, 5-merous. Calyx almost absent-10 mm long, the tube 1-2 mm, the lobes 0-9 mm, short and acute to long attenuate, the acumens 1-8 mm long, with hairs like those of the stem. Corolla 2-6 cm in diameter, very rotate to rotate-pentagonal, white to pink to lilac to blue to purple to red-purple, uniform or with white acumens or with a secondary color stippled, in bands, or in the star, adaxially or abaxially or both, the tube 1-2 mm long, the acumens 3-5 mm long, often prominent, the corolla edges flat, not folded dorsally, glabrous abaxially, minutely puberulent adaxially, especially along the midribs, ciliate at the margins, especially at the tips of the corollas. Stamens with the filaments 1-2 mm long; anthers 3-8 mm long, cordate at the base, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 9-13 mm x ca. 1 mm, exceeding stamens by 7 mm, straight, papillose in the distal half; stigma capitate.
Fruit a globose to ovoid berry, 1-4 cm in diameter, green to green tinged with white or purple spots or bands when ripe, glabrous.
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.
Solanum tuberosum L., Sp. Pl. 185. 1753.
Hierbas erectas o escandentes, hasta 1 m de alto, estoloníferas y con tubérculos, escasa o densamente víscido-pubescentes con tricomas simples, inermes. Hojas solitarias, mayormente 59-imparipinnadas, folíolos ovados o elípticos, hasta 8 cm de largo, ápice agudo o acuminado, base obtusa; folíolos intersticiales presentes o ausentes; pecíolos delgados, hasta 5 cm de largo; folíolos pseudostipulares hasta 1 cm de largo. Inflorescencias panículas terminales con muchas flores, tardíamente laterales, pedúnculos 410 cm de largo, bifurcados, pedicelos 1020 mm de largo; cáliz 58 mm de largo, lobado hasta cerca de la 1/2 de su longitud, lobos lanceolados, largamente acuminados; corola 2040 mm de diámetro, blanca, rosada, azul o purpúrea, frecuentemente amarilla cuando seca, levemente lobada, lobos ovados; anteras 57 mm de largo. Baya subglobosa, 1.52.5 cm de diámetro, glabra, amarilla; semillas ca 2 mm de diámetro.
Cultivada por sus tubérculos comestibles; 8001000 m; fl feb, sep; Grijalva 4029, Sandino 2314; nativa del oeste de Sudamérica y cultivada en casi todo el mundo. "Papa".
Landrace populations of Solanum tuberosum grow from western Venezuela south to northern Argentina (Andean populations), and then with a gap of distribution in south-central Chile in the islands of the Chonos Archipelago and the adjacent mainland Chile (lowland Chilean populations), as cultivated plants; with the Andean populations growing from 1000-4300 m in elevation, and the lowland Chilean populations at or near sea level. Landrace populations are still maintained out of their natural range, introduced in post-Colombian times, in Mexico and Central America, the Shimla Hills of India, and in the Canary Islands. The modern cultivated potato (also classified as Solanum tuberosum), is cultivated worldwide.