In Jain practice, many followers avoid all underground plant parts (root vegetables and similar parts) because harvesting can harm tiny life forms in the soil. Lotus stem is a rhizome that grows underground, so in strict Jain dietary rules it is generally avoided as a root/underground plant part.

However, practices can vary by community and family. Some might permit it, especially if it is clearly a stem rather than an underground tuber, or depending on local tradition (Digambar vs. Shwetambar). The most reliable approach is to ask your guru or senior Jain household members in your community for their guidance.

If you’d like, I can look up Jain authoritative guidance on lotus stem from JainKnowledge.com and share what they present.