- Name also: Common Hop, European Hop
- Family: Hemp Family – Cannabaceae
- Growing form: Perennial herb-stemmed climber (bine). Rootstock woody.
- Height: 1–6 metres (approx. 1–6.5 yards) long. Stem 4-edged, rough-haired, hairs descending oblique.
- Flower: Plant dioecious (pistillate and staminate flowers on different plants). Pistillate flower: tepal scale-like, lime green. Stigmas 2, thread-like. Pistillate inflorescence cone-like, lime green, 2–3 cm (0.8–1.2 in.) long, with strong fragrance, stalkless flowers in pairs in axils of subtending bracts. Staminate flower: perianth regular (actinomorphic), lime green, approx. 5 mm (0.2 in.) broad, tepals 5. Stamens 5. Staminate inflorescence long-stalked, many-branched, lax, up to 10 cm (4 in.) long raceme.
- Leaves: Opposite, long-stalked, stipulate, leaf pairs’ stipules fused. Blade 3–5- (occasionally 7-) lobed, smallest entire, sharply serrated, rough.
- Fruit: Approx. 3 cm (1.2 in.) long achene surrounded by tepals.
- Habitat: Seaside, lakeside and stream-bank broad-leaved forests. Female plant also left over from cultivation in yards, ruins and hegderows near inhabited areas.
- Flowering time: July–August.
The ”hop cones” that are added to malted drinks are the plant’s pistillate inflorescence, whose glandular hairs make a bitter resin. These give the beer its characteristic flavour, stop it going off and clarify it. Apart from the brewing industry, hops are also cultivated as a medicinal herb and for their fibre. Its inflorescence was a means of paying tax when Finland was part of Sweden, and peasants were legally obliged to cultivate hops until 1915. There was a time when almost every croft and small cottage had a hop trellis in the yard. Later on there were even hundreds of commercial hop fields for the brewery industry – the Finnish equivalent of southern European vineyards. Nowadays the Finnish brewery industry uses imported hops, and the plant is seldom seen as an ornamental either.
Hop is a native plant to southern and central Finnish shores and broad-leaved forests on stream banks. It uses tree trunks for support as it winds around them, always to the left i.e. clockwise. All other climbers in Finland go to the left i.e. anti-clockwise. Hop has spread a lot to forest that is close to currently or formerly inhabited places, so it is difficult to distinguish between wild plants and escapes from cultivation. Finding the male plant is a sure sign of the origin of the stand: only female plants are cultivated, and male plants are kept away from the hop fields because fertilisation reduces the quality of the crop. In southern coastal areas there are usually both male and female plants, but inland stands often consist of only one sex or the other, and seeds are not produced. The most northerly separate stands are a legacy from a time when the place has been coastal broad-leaved forest. Hop began to grow inland at a time when Finland’s coastline was washed by the Litorina Sea, some 7,000–8,000 years ago. It is unbelievable, but true, that hop seeds that germinated then are still winding their way around alder trees today – it was already thousands of years old when the Finnish people were chanting in their national epic the Kalevala, “beer is made of barley, hop makes the drink”.