Hazel

Hazels are trees or big bushes.

They grow tasty nuts. People can eat these nuts. Many animals love them too. Red squirrels and deer eat them.

In the spring, they grow yellow flowers. These flowers come out before the leaves. Some hazels have soft leaves around the nut. Other hazels have prickly leaves. They are very old plants. Fossils show they lived with dinosaurs. Hazels are very special plants.

Hazels are trees and large shrubs. They grow in the Northern Hemisphere. These plants are very old. Fossils show they lived with dinosaurs.

In early spring, they grow flowers. The male flowers are long and pale yellow. We call these catkins. The female flowers are very small. They stay hidden in buds. The pollen from these flowers can cause allergies.

Hazels grow tasty nuts. Each nut is inside a husk. This husk is called an involucre. Some husks are soft and leafy. Other husks are stiff and spiny. Many animals love to eat these nuts. Red squirrels and red deer eat them. Dormice also like them. People eat hazelnut kernels too. People use the wood for many things. They make baskets and fences from the branches. Some people grow special types in gardens. These might have purple leaves or curly stems. Some hazels grow as small shrubs. Others grow as tall trees. Some can reach 35 meters tall.

Hazels are special plants that grow as large shrubs or trees. They belong to the genus Corylus. Most of these plants live in the temperate Northern Hemisphere. You might know them best for their tasty fruit. This fruit is the hazelnut. The hazelnut is actually a nut. It is surrounded by a protective covering called an involucre, or a husk. Some husks are soft and leafy. Other types are stiff and have sharp spines.

Watching a hazel grow is a step-by-step process. In the early spring, flowers appear before the leaves do. These plants are monoecious, which means they have both male and female flowers on one plant. The male flowers look like long, pale yellow catkins. The female flowers are very tiny and stay hidden in buds. You might only see small, bright-red parts called styles. These flowers release pollen into the air. This pollen can sometimes cause allergies in people.

These plants have a very long history on Earth. Scientists have found hazel fossils from the Cretaceous period. This means they were around when dinosaurs lived. The oldest confirmed species is called Corylus johnsonii. It was found in rocks from the Ypresian age in Ferry County, Washington. Today, there are about 14 to 18 different species of hazel. Some groups of scientists even disagree on the exact number. For example, the Flora of China counts 20 species.

Different hazels grow in different ways and places. Some are small shrubs that grow to 12 meters tall. The American hazel grows in eastern North America. The common hazel grows in Europe and western Asia. Other types are tall trees that reach 20 to 35 meters. The Chinese hazel grows in western China. Some of these trees have very unique looks. You can find garden plants with purple leaves or curly stems. These are called cultivars.

Hazels are important to many living things. Red squirrels, red deer, and dormice all eat the nuts. Even certain moths and fungi depend on these plants to live. Humans use hazel in many ways too. We use the wood to make baskets and fences. This is often done through a method called coppicing. This means cutting the plant so new shoots grow back. People also enjoy eating the kernels inside the nuts. Some kernels make up nearly half of the whole fruit.

Hazels are plants belonging to the genus Corylus. They grow as deciduous trees or large shrubs. Most species are native to the temperate Northern Hemisphere. Botanists usually place them in the birch family, known as Betulaceae. However, some botanists suggest they belong to a separate family called Corylaceae. These plants are highly significant because they produce edible nuts. The fruit of the hazel is the hazelnut.

The reproductive process of the hazel begins very early in the spring. Hazel plants are monoecious, meaning they have both male and female flowers on one plant. The male flowers appear as long, pale yellow catkins. The female flowers are very small and stay mostly hidden in the buds. You can only see their bright-red styles, which are 1 to 3 mm long. These flowers release pollen into the air. This pollen can cause allergies in some people during late winter or early spring. Under a microscope at 600x magnification, the pollen shows a specific granular texture. It has three conspicuous pores that help scientists identify it.

Once the flowers are pollinated, the plant develops its fruit. The fruit is a nut that is 1 to 2 cm in diameter. Each nut is surrounded by a structure called an involucre. This involucre is a husk that partly or fully encloses the nut. The shape and structure of this husk are vital for identifying different species. In many cultivars, the kernel inside the nut makes up between 33.20% and 49.5% of the total fruit. This is especially true for varieties grown near the Mediterranean Sea.

Scientists group the various hazel species based on their growth habits and husks. One group consists of multiple-stemmed, suckering shrubs that reach up to 12 m tall. These have a soft, leafy involucre that is about the same length as the nut. Examples include the American hazel (Corylus americana) and the common hazel (Corylus avellana). Another group includes species with a long involucre that forms a "beak." This group includes the beaked hazel (Corylus cornuta) and the filbert (Corylus maxima). A third group consists of single-stemmed trees that can reach 20 to 35 m tall. These have stiff, spiny involucres. Examples include the Chinese hazel (Corylus chinensis) and the Himalayan hazel (Corylus ferox).

The history of the hazel stretches back millions of years. Fossils show that hazels existed during the Cretaceous period. This means they were likely part of the diet of certain dinosaurs. The oldest confirmed species is Corylus johnsonii. Scientists found its fossils in Ypresian-age rocks in Ferry County, Washington. Today, there are approximately 14 to 18 recognized species. However, there is some disagreement among experts. The World Flora Online accepts 17 species, while the Flora of China accepts 20 species.

Hazels play a major role in their local ecosystems. At least 21 species of fungus have a mutualistic relationship with the plant. This means the fungus and the hazel help each other survive. For example, the fungus Lactarius pyrogalus grows almost exclusively on hazel. Several rare species of Graphidion lichen also depend on these trees. Many animals rely on the nuts for food, including red deer, dormice, and red squirrels. In the UK, five different species of moth specialize in feeding on hazel. However, some pests can cause trouble. An aphid called Myzocallis coryli uses hazel as its host and has caused major damage to hazel farms in Oregon.

Humans have used the hazel for many practical purposes throughout history. The wood is a traditional material for making baskets, fences, and even the frames of coracle boats. People often use a method called coppicing to manage hazel. This involves cutting the plant so that new shoots grow back from the base. This allows for regular harvests of wood every few years. There is even a seven-year cycle used for making hurdles, which are portable fences. Beyond utility, hazels appear in many cultures. The Celts believed hazelnuts provided wisdom and inspiration. In German folklore, the "Cinderella" story mentions a hazel branch that grants wishes.