A bulbous perennial of the Iridaceae family, Crocus tommasinianus is native to the Balkans, mainly Dalmatia and Bosnia-Herzegovina, where it colonizes light woods, edges, and limestone meadows at modest to medium altitudes.
The 'Roseus' cultivar stands out within the species by its distinctly pink hue: the tepals display a fairly bright pink-mauve, slightly more intense on the still-closed bud, which lightens upon full opening of the flower to reveal a white throat. The bright yellow-orange anthers stand out sharply against this light interior. The flowers, modest in size and elegant, open widely in the sun. The foliage is typical of the genus: narrow, dark green leaves, streaked with a well-visible fine silver median line.
In its natural habitat, the flowering of the type species extends from February to March. In cultivation, 'Roseus' blooms at the same period, often among the first crocuses of the season, sometimes as early as late January during mild winters.
It thrives in well-drained soil, in full sun or under deciduous trees, and naturalizes easily by division of corms and spontaneous reseeding. Planted en masse, it forms a generous pink-mauve carpet on the ground, unique among the early crocuses that generally dominate with cold violet and lilac shades.