S. tuberosum L. f. sebastianum Buk. et Lechn.

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S.Ì. Bukasov. Potatoes of South America and their breeding use, Leningrad, 1933, p. 90

Diagnosis: The form is prettu close to Francesa negra. Tubers are elongate, purplish-black, coloured in and under the skin, often speckled with white areas near eyes. Flesh is yellowish, colored with anthocyan in vascular ring. Leaves are with wide, large, glossy leaflets, weakly dissected. Formula: 4/2-5/3, 2,4-5+2+2. The leaf is clearly distinctive from elegans, it is shorter.
Pedicels under articulation are 20 mm, above articulation from 7 mm to 10 mm, green, articulation is not coloured, sometimes clearly defined, pubescence is very short, dense, straight.
Calyx is quite big, up to 12 mm long, green and colored at the basis,  symmetric or bilabial, acumens are narrow (or leaf-like), reflected, the length is from one-third of the calyx length until half-length and more.
Violet corolla, yellowish star, large, radius about 16-20 mm , lobes are larte (about 8-10 mm long), apex of a medium size (about 3 mm).
Anthers are medium-sized, about 5,5-6 mm, sometimes underdeveloped in a displaced conic or straight column, sometimes colored black with anthocyan along the suture and the back, like also the anther pores.
Stamen filaments are yellow, thick, long. Style is thick (like by E. Rose) long, straight. Stigma is big and not high with 2 yellow points. Early form. Halm goes yellow earlier than by the other chilean and is strongly susceptible to late blight.
Is grown near Chiloe, San Sebastiano island. Juz. ¹ 2034 "Soldada".
Similarity with Soldada and Francesa negra: habitus, leaf shape (although it is glossy), shape of anther column.
Difference: shorter pubescence.