Humulus lupulus

Hops are a climbing plant.

These plants have special flowers. The female flowers look like small green cones. People call these cones hops. They have a very strong smell.

These hops are used to make beer. They add a bitter taste to the drink. They also help keep the drink fresh. This is why people grow them.

Some hops have yellow leaves. These are called golden hops. They are used to make gardens look pretty. They are a beautiful plant to see.

Hops are a climbing plant. They belong to the hemp family. These plants can live for up to 20 years. They use stiff, downward hairs to climb. This helps them stay stable as they grow.

Hops have separate male and female plants. This is called being dioecious. The female flowers are shaped like small cones. We call these cones hops. They have a strong smell and a bitter taste. These cones help keep beer fresh. They also add flavor and foam.

Many things affect how hops grow. For example, long summer days trigger flowering. Changes in water or heat can cause stress. This stress can change how bitter the plant is.

Some people grow hops for gardens. One kind has yellow leaves. It is called the golden hop. It is a very pretty plant to see.

Hops are a special kind of climbing plant. They belong to the Cannabaceae family, which includes hemp. These plants are perennials, meaning they can live for up to 20 years. In the spring, they send up new shoots from a hardy root part called a rhizome. During the autumn, the plant dies back to this root. Hops are very important to the brewing industry. They are used to add flavor and help preserve beer.

The way a hop plant grows is quite interesting. It is often called a bine instead of a vine. This is because it has stiff hairs that face downward to help it climb. The plant is dioecious, which means there are separate male and female plants. The male flowers are called staminate and do not have petals. The female flowers are called pistillate and have petals around the fruit. These female flowers form small, fragrant cones known as hops.

People have used hops for a very long time. We have records of hops being used in brewing since 768 CE. In that year, King Pepin gave hops to a monastery in Paris. Another record from 859 CE shows hops being grown in Germany. Before hops became popular, people used other plants like Myrica gale to flavor drinks. Hops eventually became the favorite because they help keep the drink fresh.

There are many different types of hops found around the world. There are five main varieties of the plant. These include varieties found in Europe, West Asia, and North America. Some grow in the eastern part of North America, while others are in the west. One special kind is the 'Aureus' cultivar, also called the golden hop. It has yellow leaves and is grown in gardens for its beauty.

Hops contain many natural substances that change how they taste. They have oils and acids that make beer taste bitter. These bitter flavors come from special acids called iso-alpha acids. The plant also contains other things like myrcene and linalool. These compounds help create the smell and foam in many drinks. Scientists study the hop genome to understand these traits better. The hop genome is actually very large, similar in size to a human genome.

Humulus lupulus, commonly known as the hop plant, is a perennial climbing plant. It belongs to the Cannabaceae family, which also includes hemp and marijuana. As a perennial, it can live for up to 20 years. Every spring, the plant sends up new shoots from a cold-hardy rhizome. In the autumn, the plant dies back to this underground root system. Hops are essential to the brewing industry. They are used to provide flavor, aroma, and preservative qualities to beer.

The growth habit of the hop is unique. While many people call it a vine, it is more accurately described as a bine. This is because the plant has stiff, downward-facing hairs. These hairs provide stability and allow the plant to climb upward. The plant is also dioecious, meaning it has separate male and female plants. The male flowers, or staminate flowers, do not have petals. The female flowers, or pistillate flowers, have petals that envelope the fruit. These female flowers form fragrant, cone-shaped structures called strobili, which are commonly known as hops.

Inside these female cones, the plant produces specific structures. The fruit of the plant is an achene, which is a type of dry fruit that does not split open when it is mature. These achenes are surrounded by tepals. Concentrated on the fruit are glands that secrete lupulin. This substance is vital for the plant's chemical profile. The flowering process is triggered by longer summer days. In the Northern Hemisphere, this usually occurs around July or August. The fragrant flowers rely on the wind for pollination.

Humans have cultivated hops for many centuries. Historical records show that King Pepin donated hops to a monastery in Paris in 768 CE. Later, in 859 CE, documents from a monastery in Freising, Germany, recorded the cultivation of hops. Before hops became the standard, brewers used other plants like Myrica gale to flavor their drinks. Hops eventually became the preferred choice because they contain natural preserving agents. These agents help prolong the viability of a brew. Over thousands of years, human selection has enhanced the aroma, bitterness, and yield of various varieties.

The chemistry of Humulus lupulus is complex and highly valued. It contains several secondary metabolites, including myrcene, humulene, xanthohumol, myrcenol, and linalool. These compounds, along with tannins and resins, impact the flavor of products like beer. The characteristic bitterness in hop-based products comes from acids composed of prenylated polyketides. Specifically, iso-alpha acids are the main components responsible for bitterness. Other compounds help create the foam found in beer. Scientists have identified specific genes, such as geranyl diphosphate synthase and chalcone synthase, that influence these taste expressions.

There are five distinct varieties of the species distributed across the globe. The variety H. l. var. lupulus is found in Europe and western Asia. H. l. var. cordifolius is native to eastern Asia. In North America, there are three varieties: H. l. var. lupuloides in the east, H. l. var. neomexicanus in the west, and H. l. var. pubescens in the midwestern and eastern regions. There are also many cultivated varieties, or cultivars. One example is 'Aureus', a golden hop with yellow leaves. This cultivar is grown for ornamental use in gardens and holds a Royal Horticultural Society Award of Garden Merit.

Research into the hop plant continues to reveal new connections. The hop genome is quite large, appearing similar in size to the human genome. This complexity makes it difficult for scientists to identify all genetic properties. Interestingly, the hop shares about a 73% genomic overlap with Cannabis sativa. They also share significant overlap in the cannabidiolic acid synthase gene. Studies have also looked at the medicinal potential of hops. For example, extracts of bitter alpha-acids may act as sleep aides. Additionally, the antimicrobial properties of hop extracts have been used in natural deodorants.