Romania has issued a set of four stamps on thorn flowers. The stamp with the face value of lei 4.70 reproduces the image of the Dipsacus fullonum plant, known by the common name of wild teasel. It is native to Eurasia and North Africa, but it is known in the Americas, Southern Africa, Australia and New Zealand as an introduced species and often anoxious weed. The stamp with the face value of lei 5.00 reproduces the image of Centaurea solstitialis, an annual plant of the Asteraceae family, native to the Mediterranean Basin. During the vegetative stage, it forms a rosette of non-spiny leaves, 5 ‒ 20 cm in diameter, and as summer approaches it produces a tall stalk of 10 ‒ 100 cm.
As the name suggests, it blooms in late summer, from after the midsummer solstice to early autumn. The flowers are bright yellow, oblong globular and show spiny long and branched appendages, on the base.
The stamp with the face value of lei 6.00 reproduces the image of the Echinops ruthenicus plant. This species is part of the sunflower family, the Asteraceae family. Echinops ruthenicus is a perennial plant which grows up to a height of 70 cm, has leathery leaves, deeply serrated and thorny. The stamp with the face value of lei 8.10 reproduces the image of the Ononis spinosa plant, that is commonly known as spiny rest-harrow. It belongs to the Fabaceae family and is a small bush, 30 ‒ 60 cm tall, with very spiny twigs on the stem.