Cladus: Eukaryota
Regnum: Plantae
Divisio: Magnoliophyta
Classis: Magnoliopsida
Ordo: Rosales
Familia: Cannabaceae
Genus: Humulus
Species: H. lupulus - H. scandens -

Vernacular names
Internationalization
Svenska: Humlen

Humulus, Hop, is a small genus of flowering plants native to temperate regions of the Northern Hemisphere. The female flowers (often called "cones") of H. lupulus are known as hops, and are used as a culinary flavoring and stabilizer, especially in the brewing of beer. The hop is part of the family Cannabaceae, which also includes the genera Cannabis (hemp), and Celtis (hackberries).

Description

Although frequently referred to as the hop "vine", it is technically a bine; unlike vines, which use tendrils, suckers, and other appendages for attaching themselves, bines have stout stems with stiff hairs to aid in climbing. It is a perennial herbaceous plant which sends up new shoots in early spring and dies back to the cold-hardy rhizome in autumn. Hop shoots grow very rapidly and at the peak of growth can grow 20 to 50 centimetres (8 to 20 in) per week. Hop bines climb by wrapping clockwise around anything within reach, and individual bines typically grow between 2 to 15 metres (7 to 50 ft) depending on what is available to grow on. The leaves are opposite, with a 7 to 12 cm (2.8 to 4.7 in) leafstalk and a heart-shaped, fan-lobed blade 12 to 25 cm (4.7 to 9.8 in) long and broad; the edges are coarsely toothed. When the hop bines run out of material to climb, horizontal shoots sprout between the leaves of the main stem to form a network of stems wound round each other.

Male and female flowers of the hops plant develop on separate plants (dioecious). Female plants, which produce the hops flowers used in brewing beer, often are propagated vegetatively and grown in the absence of male plants. This prevents pollination and the development of viable seeds which are sometimes considered undesirable for brewing beer.[1]

Species

There are three species, one with five varieties:

* Humulus japonicus (syn. H. scandens). Asian Hop. Leaves with 5–7 lobes. Eastern Asia.
* Humulus lupulus. Common Hop. Leaves with 3–5 lobes. Europe, western Asia, North America.
o Humulus lupulus var. lupulus. Europe, western Asia.
o Humulus lupulus var. cordifolius. Eastern Asia.
o Humulus lupulus var. lupuloides (syn. H. americanus). Eastern North America.
o Humulus lupulus var. neomexicanus. Western North America.
o Humulus lupulus var. pubescens. Midwest North America.
* Humulus yunnanensis. Yunnan Hop. Leaves with 3–5 lobes, densely hairy below. Southeast Asia (endemic in Yunnan, China).

Brewers' hops are specific cultivars, propagated by asexual reproduction: see List of hop varieties.

Hop varieties
Main article: List of hop varieties

Hop applications

Hops are boiled with the wort in brewing beer. They impart a bitter taste and aromatic flavor, and prevent fermentation from being too rapid.[2]

In pharmacy lupulus is the designation of hop. The dried catkins of the female plant of H. lupulus are used to prepare infusion of hop, tincture of hop, and extract of hop.[2]

Hops in culture

Hops were voted the County flower of Kent in 2002 following a poll by the wild flora conservation charity Plantlife.[3]

References

1. ^ Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries. Economic Plants and their Diseases, Pests and Weeds. Humulus lupulus.
2. ^ a b Wikisource-logo.svg "Hop". Collier's New Encyclopedia. 1921.
3. ^ Plantlife website County Flowers page

* Lee W. Janson, Ph. D.; Brew Chem 101; Storey Publishing; ISBN 0-88266-940-0 (paperback, 1996)