ere the land has been difficult to cultivate.
It includes brush grass, reeds, and licorice. The last two have
commercial value. Most of the original lowland deciduous forests have
been removed, and grain flourishes on the level expanses where the soils
are favorable. Other food and fodder crops are grown to satisfy local
requirements. The foothills of the Stara Planina are dotted with
orchards; plums are the most prevalent fruit in these northern areas.

The depression, or geological trench, between the Stara Planina and the
Sredna Gora ranges, which is at the near center point of the country and
contains the upper valleys of the Tundzha, Stryama, and Topolnitsa
rivers, is sheltered and very humid and is ideal for the raising of
roses. One in particular, Rosa Alba, has become known as Bulgaria's
gold. Its flower is not an especially lovely variety, but it is
extremely rich in the rose oil that is the basic fragrance in many
perfumes and a flavor in certain liqueurs. Fields of them flourish in
the Kazanluk area, the so-called Valley of Roses.

The Thracian Plain, between the Sredna Gora and the Rodopi, originally
featured a mixture of midlatitude forest and Mediterranean flora. The
forests have been removed from the level lands and have been replaced by
a diversification of crops, including truck vegetables, fruit orchards,
strawberries, raspberries, vineyards, tobacco, and cotton. The plain
also produces a variety of herbs and medicine derivatives. Digitalis is
produced from foxgloves; menthol, from peppermint; opium, from a species
of poppy; linseed oil, from flaxseed; laxatives, from iris and rhubarb;
and castor oil, from the castor bean. All of them are grown on this
plain.

Where the plain touches the Black Sea, varieties of tropical or
subtropical vegetation appear. Vegetation is dense along the Kamchiya
River and on the banks of a few of the smaller streams as they approach
the sea. Reeds, lianas, exotic flowers, and huge old trees that grow
nowhere else in the country flourish in this region.

In the southern Rodopi, where a few of the river valleys--those of the
Struma, Mesta, and Maritsa, for example--open to the south, the
vegetation is typically Mediterranean. Natural species include the
Mediterranean scrubby underbrush, maquis, and an assortment of flowering
plants and shrubs. Vineyards and subtropical fruit grow well in these
valleys. Such areas produce the country's peaches, figs, and peanuts.

Mounta