The WALA Plant Library
Hops

Synonyms for Hops: Hop
Scientific Name: Humulus lupulus L.
Family: Cannabaceae (hemp family)

Description:

Cultivated plants are impossible to overlook, but as its flower-bearing stems mature the hop is easily discerned even in its native habitat, hedges and copses close to water. In the wild these stems grow to a length of three to six metres; the stems of cultivated plants can reach up to 12 metres. They twine around other plants, twisting – unusually for climbing plants – in a clockwise direction, and reach lofty heights with the aid of climbing hairs which bend and cling at even the slightest touch. And they do all this at impressive speed. In just one day a stem can grow as much as 30 centimetres. From July to August the flowers develop, growing in among the leaves, which are rough and have three to seven lobes. Hops are dioecious, which means that plants bear purely male or purely female flowers – the flowers of most other plants contain both female and male parts. The male flowers are an inconspicuous greenish-white colour and bloom in loose clusters. It is the female inflorescences, which are wind-pollinated, whose characteristic appearance when mature is more familiar to us. The intrinsically inconspicuous flowers grow crowded together and surrounded by bracts, so that they resemble ears of corn. In due time they swell to form hop ‘cones’, each of which comprises up to 60 individual flowers. The scaly bracts of these cones serve to assist the flight of the ripe seeds and are equipped with glands that secrete lupulin, a sticky powder consisting of resins and essential oils. As winter approaches, the perennial hop withdraws into its roots and the shoots above the ground die back entirely. Fresh shoots sprout the following spring from buds formed on underground rhizomes. Hops can be propagated from these rhizome buds once they have formed their own root system and have been separated from the mother plant.