The Collaborative International Dictionary of English v.0.48:

Plumbagineous \Plum`ba*gin"e*ous\
   (pl[u^]m`b[.a]*j[i^]n"[-e]*[u^]s), a. (Bot.)
   Pertaining to natural order (Plumbagine[ae]) of
   gamopetalous herbs, of which Plumbago is the type. The order
   includes also the marsh rosemary, the thrift, and a few other
   genera.
   [1913 Webster]