Source : Webster's Revised Unabridged Dictionary (1913)

Polemonium \Pol`e*mo"ni*um\ n. [NL., fr. Gr.? a kind of plant.]
   (Bot.)
   A genus of gamopetalous perennial herbs, including the
   Jacob's ladder and the Greek valerian.

Source : WordNet®

polemonium
     n : any plant of the genus Polemonium; most are low-growing
         often foul-smelling plants of temperate to arctic regions