Source : Webster's Revised Unabridged Dictionary (1913)

Riga fir \Ri"ga fir`\, [So called from Riga, a city in Russia.]
   (Bot.)
   A species of pine ({Pinus sylvestris}), and its wood, which
   affords a valuable timber; -- called also {Scotch pine}, and
   {red or yellow deal}. It grows in all parts of Europe, in the
   Caucasus, and in Siberia.