Cistus or Rockrose is my favorite plant, I have planted 15 in my garden. It was lucky, not knowing that they thrive into poor soil. It reminds me of my holidays in Provence when I first visited Grasse as a teenager. The smell is the reason it is my beloved plant; it gets stronger at the end of the day, especially when it's been very hot. I love the way it stucks to your skin. You can keep the smell longer when you stroke the leaves.

Cistus (from the Greek kistos) is a genus of flowering plants in the rockrose family Cistaceae, containing about 20 species.

The leaves are evergreen, opposite, simple, usually slightly rough-surfaced, 2–8 cm long. In a few species (notably C. ladanifer), the leaves are coated with a highly aromatic resin called labdanum.

Labdanum – from the Cistus plant – is a pillar of chypre perfumes and many Orientals.  What you smell actually comes from a sticky brown resin, taken from a plant that grows (often in very inhospitable, dry locations) in the Mediterranean, North Africa and the Middle East.  Harvesting techniques have become somewhat more sophisticated since the time when labdanum was collected from the coats and beards of sheep and goats that grazed on these tough little shrubs…!  (Labdanum is today extracted from the leaves using solvents, although the branches can also be boiled.)

One of the reasons it’s so widely used now is that it mimics the scent of ambergris. (Ambergris is formed from a secretion of the bile duct in the intestines of the sperm whale, and can be found floating on the sea or washed up on coastlines. It is sometimes found in the abdomens of dead sperm whales.)
Read this olfactotherapy article about cistus