"the dusky verses were as fragrant as though they had lain all those years in myrtle, lavender and vervain"

Myrtle is an evergreen shrub or small tree with a white, star-shaped flower and round black berries.   

Lavender is a member of the mint family, and is usually found as a small shrub with fragrant leaves and pale purple flowers.

GNU Free Documentation LicenseLavender - Credit: Fir0002

 Vervain  is a herbaceous flowering plant. 

GNU Free Documentation LicenseVerbena(vervain) - Credit: Sphl