The Rfam database is a collection of RNA families, each represented by multiple sequence alignments, consensus secondary structures and covariance …
https://rfam.org/PmiREN (Plant miRNA ENcyclopedia) is a comprehensive functional plant miRNA database.
https://pmiren.com/Predict secondary structures of single stranded RNA or DNA sequences.
http://rna.tbi.univie.ac.at//cgi-bin/...