Citrus: Bright peel and juice: lemon, lime, orange, grapefruit. Often driven by limonene, the same compound that makes citrus rind smell like citrus rind.
Candy Sweetness: Confection rather than fruit: sugar, tropical brightness, an almost artificial sweetness. Ester-driven, and the register modern dessert-lineage breeding has pushed hardest.
Dark Fruit: Deep and jammy: grape, blueberry, plum, berry. Comes from esters rather than terpenes, which is why two strains can share a terpene profile and taste nothing alike.
Floral: Blossom and petal: lavender, rose, violet. Linalool sits behind much of this; it is what makes lavender smell like lavender, and it turns up in cannabis more often than people expect.
Herbaceous: Green, leafy and cooling: sage, tea, mint, cracked pepper. Pinene and terpinolene drive the fresh green edge; the peppery bite is caryophyllene, the only terpene known to bind directly to a cannabinoid receptor.
Earth: Soil, forest floor, bark and pine. Myrcene and humulene do most of the work here — humulene is the same compound that makes hops smell like hops.
Funk: Sour, savory, barnyard: skunk, aged cheese, pungency. Like Gas, this is sulfur chemistry rather than terpenes, which is why it survives drying and curing so stubbornly.
Gas: Fuel and solvent: diesel, chemical sharpness, ammonia. Not a terpene smell at all — the gassiness in cannabis comes from volatile sulfur compounds, the same family that gives skunk and garlic their punch.
Dessert & Cream: Bakery and dairy: vanilla, butter, coffee, toasted nut. The Cookies and Gelato register, and the newest of the nine in cannabis terms — it barely existed before the 2010s.

From Leafly user reviews — crowd-reported impressions, not lab measurements. How this works