Take a few chapters from a John le Carre spy thriller, add a hefty dose of exotic travelogue, blend with one of the best books on bulb growing ever written, and you've got ''Buried Treasures''. For decades, Ruksans has been scouring remote and dangerous regions of Europe and Asia to bring back the botanical treasures that he offers through his nursery, often contending with corrupt government agents, armed rebels, drunken drivers, and even (before the fall of the Soviet Union) the KGB. Packed with accounts of his extensive travels, ''Buried Treasures'' also offers an abundance of trustworthy information about the care and cultivation of every major and minor genus of bulb-forming plant.