The Caucasian primrose(Primula acaulis subsp. Rubra) with its large pink-purple flowers is easy to spot in early spring along the brownish landscape covered with dry oak leaves. The purple flowers and bright green leaves of the Caucasian Primrose appear around mid-March along the southern Black Sea coast or even in late February in the warmer parts of Strandzha Mountain. These beautiful plants rush to take advantage of the first spring rays, because later, when the forest turns green at its fullest, sunlight rarely reaches the lower forest beds.
Caucasian primrose is an herbaceous perennial plant with no stem, hence its other name – stemless primrose. The flowers are approximately 2-3 cm in diameter, coloured in pink to red or pale purple and placed on slender flower stalks that extend from the center of the leaf rosette. The flower stalks are covered with rather shaggy hairs; the leaves are shovel-shaped gradually narrowed in short leaf stem.
The wild Caucasian primrose is rare, but in Strandzha Mountain enjoys widespread. The reason is the good environmental conditions that this mountain can offer - a relatively mild winter, high humidity and rich humus soil. They resemble the environmental conditions of the Crimea and the Caucasus regions, native to the Caucasian primrose’s "brothers" and "sisters".
In Bulgarian this tertiary relic is protected in the nature reserves "Silkosia" and "Lopushna" in Strandzha Mountain and in "Baltata" a nature reserve along the Creek of Batova River in northeast Bulgaria. Deforestation, collection of bouquets, uncontrolled grazing, trampling by tourists have a negative impact on the Caucasian primrose distribution have.