S. andigenum Juz. et Buk. var. ccusi Buk. et Lechn.

S.M. Bukasov. Potatoes of South America and their breeding use, Leningrad, 1933, p. 62.

Diagnosis: Similar to Beruntun in a small length of pedicle above articulation (7-8 mm), long stick up calyx pubescence, long stamen filaments. Tubers are blue. Leaf formula is 6/3 (6 pairs of leaflets, three out of them are small) II6+2+2 (six primary leaflets + two secondary leaflets (basiscopic) + two acroscopic; the number II indicates the second series). Very large wide leaflets. A calyx with narrow lobes and long, narrow and slim outstanding acumens is characteristic. A big corolla radius = 18 mm, a smaller= 13, petal width = 21, length= 10 mm, acumen= 5 mm. Anthers are in a straight or slightly conic column. Style is covered with papillae for 1/3, stigma is of a medium size.
Forms berries more abundantly than Beruntun. Berries are short and oval. Apparently, tends to leaf-roll.
Differences from Beruntun: plants are very high, habitus is very peculiar, of the type close to Taccla, but powerful, stems are sometimes decumbent, but with numerous high axillary branches, stems are strongly colored, calyx is colored, anther basis are not heart shaped, stigma is clearly conic.
Used for Chuno (bitter according to Herrera).
Cultivated in dep. Cuzco: Yana machai (Juz. 1284), in Acomayo: Pomacanchi (Juz. 1170) and in many other places in South Peru.
Indigenous names: alcca ccussi, huana , yana huana, puca-huana, ppalta-papa.
The name Huana is known in Bolivia, it is Huana laca ("dry mouth") which is used according to Cevallos for the sort with rounded tubers of a "leaden" (pale violet?) color and very white flesh, not tasty and very dry, which the Indians eat with "ppasa" clay, dissolved in salty water.
It is not clear whether the Peruvian and Bolivian sorts are synonymous.
The name palta (flat) is used in Bolivia, apparently, for a different sort, but also for a Chuno sort with very flat white tubers.