There are thousands of varieties in the world. A reasonable criterion of classification is based on the duration of the culture cycle, that can be from 90 to 200 days. In this way, we have early, semiearly, semilate and late potatoes.

The potato is a tuber rich in starch, round or oval, with some protuberances called "eyes", that are growth buds. The size varies in a considerable and the colour of the skin ranges from yellow to purple.

As it is a widely cultivated species, the classification in varieties is made up according to different characteristics like: the colour and texture of the skin, colour of the flesh, number of " eyes", tuber shape, productivity, resistance to plagues and diseases, etc. One of the classifications is based on the size and the colour of the skin. According to this criterion we distinguish mainly 4 groups:

- Round golden: they are round or oval, with thin and smooth skin, firm and waxed texture and dry taste.
- Lenghty reddish: oval to lengthy shape, smooth and dark skin and mealiness.
- Lenghty white: elongated shape, thin and smooth white skin, firm and waxed texture.
- Round red: round shape, smooth, thin and bright red skin, firm and waxed texture.

Another criterion is the agronomic, that makes reference to the culture duration. Thus, we distinguish:

a) Early varieties, culture cycle of 90 days.
- White flesh: " Royal Kidney", " Etoile du Leon".
- Yellow or yellowish flesh: " Viola’, " Jaerla’, " Duquesa’, " Belle de Fontanay".

b) Semiearly varieties, 90 and 120 days of culture cycle.
- White flesh: " King Edward"
- Yellow or yellowish flesh: " Bintje’.

c) Semilate varieties, with a culture cycle between 120 and 150 days.
- White flesh: " Turia’, " Majestic".
- Yellow or yellowish flesh: " Desirée’.

d) Late varieties, culture cycle between 150 and 200 days.
- White flesh: " Víctor", " Up-to-Date’.
- Yellow or yellowish flesh: " Alfa’.

There is a wide range of cultivated varieties, varying the vegetal material used. At present there is an interest in the European consumption towards varieties of very firm and yellow flesh.

There are also varieties specially intended for cattle feeding.

Some potato varieties are:

Royal Kidney
Very early potato, with elongated tubers, yellowish fine skin, slight mealiness, white flesh and good yield.

Etoile du Leon
Semiearly lengthy tuber, regular shape, yellowish skin, white, fine flesh of great yield.

Palogán
Early round tubers, yellowish skin, whitish flesh and great quality.

Viola
Early claviform tubers, yellowish fine skin and flesh and excellent quality.

Jaerlat
More or less round and elongated tubers, yellowish skin, whitish flesh and great quality.

Duchess
Claviform tuber of regular size, yellowish smooth skin, yellowish flesh and great quality.

Belle de Fontenay
Tuber with varied shapes, superficial buds, dark yellow skin, yellowish flesh of excellent quality, although very demanding in soil and organic fertilizers.

Arran-Banner
Round tuber, slightly flattened, yellowish skin, whitish quality flesh.

King Edward
Oval and great tuber, uniform, yellow-pinkish skin, whitish flesh of great quality.

Bintje
Oval tuber, yellowish skin, whitish quality flesh.

Turia
Tuber of great size, white skin with pink stains, white and opaque flesh.

Majestic
Oblong tubers, yellowish skin, whitish flesh of great yield.

Desirée
Slightly lengthy potato, reddish skin, oval tuber and bright yellow flesh.

Alpha
Great tubers, round to oval shape and bright yellow flesh.