In Jainism, the guidelines about what can be consumed are based on the principle of ahimsa (non-violence) and the classification of living beings (jiva) according to the number of sense organs they possess.

Pratyek vanaspatikaay refers to "single-sensed" plant life—specifically those entities that are considered to have only one soul per body, such as grains, fruits, seeds, and certain vegetables (that do not regrow when plucked, such as tomatoes, mangoes, etc.).

According to traditional Jain dietary rules, especially for monks and nuns:

• The ideal is to consume only those plant substances that are pratyek vanaspatikaay.
• Root vegetables (like potatoes, onions, garlic, carrots) are generally avoided because they are considered to contain infinite lives (anant-kaya vanaspati) or disturb many lives when uprooted.
• Foods involving higher life forms (two-sensed and above, including animals, eggs, and some fungi) are strictly prohibited.

For laypeople (shravaks and shravikas):

• The dietary rules are slightly less strict, but the strong recommendation is to consume only those plant foods that are pratyek vanaspatikaay.
• Many Jains also avoid fermented foods, honey, and green leafy vegetables during certain months to minimize harm.

Summary: Jains are ideally supposed to consume only pratyek vanaspatikaay (single-sensed plant life). Consumption of anything apart from this (such as root vegetables, animal products, and multi-organism foods) is discouraged or prohibited, depending on one's level of observance.

If you have a more specific question about a particular food item or practice, please specify!