Pines of three species, junipers, larches, oaks, maples, willows and the Thuja Orientalis have been identified.
The firs are distinguished from the pines and larches by having their needle-like leaves placed singly on the shoots, instead of growing in clusters from a sheath on a dwarf branch.
On the French Alps a sweet exudation is found on the small branchlets of young larches in June and July, resembling manna in taste and laxative properties, and known as Manna de Briancon or Manna Brigantina; it occurs in small whitish irregular granular masses, which are removed in the morning before they are too much dried by the sun; this manna seems to differ little in composition from the sap of the tree, which also contains mannite; its cathartic powers are weaker than those of the manna of the manna ash (Fraximus ornus), but it is employed in France for the same purposes.
In Germany a fungus (Polyporus Laricis) grows on the roots and stems of decaying larches, which was formerly in esteem as a drastic purgative.
In Scotland the date of its introduction is a disputed point, but it seems to have been planted at Dunkeld by the 2nd duke of Athole in 1727, and about thirteen or fourteen years later considerable plantations were made at that place, the commencement of one of the largest planting experiments on record; it is estimated that 14 million larches were planted on the Athole estates between that date and 1826.