ca·ri·na 
(kə-rīnə, -rē-)
(kə-rīnə, -rē-)n. pl. ca·ri·nae (-nē)
A keel-shaped ridge or structure, such as that on the breastbone of a bird or of the fused lower two petals of flowers of many members of the pea family.
[Latin carīna, keel; see kar- in the Appendix of Indo-European roots.]