The Common Juniper Juniperus communis is a conifer native to Britain, Northern Eurasia and North America. It grows naturally on chalk and limestone hillsides, although in wet areas it can grow in acid bogs. It is rarely planted in gardens but there are many ‘varieties’ such as ‘Hibernica’ sold in Garden Centres. It is a shrub that does not reach more than 6m in height. Its leaves are spiky and in threes. The cones look like berries. They are used as a flavouring agent in food, beer and gin.
A Juniper shrub growing on a chalk hillside on the Chilterns.
A Juniper shrub growing in wet acid soils of the Lake District
The 1 cm long spiky needles are arranged in threes around the shoot. Each needle has a broad white band on the inner surface.
Conifers usually have male and female cones on the same tree but Junipers are dioecious with male and female on different shrubs. Pollen cones, like male flowers, release pollen and seed cones, like female flowers, develop seeds. These are pollen cones in the early stage of growth in March before they release pollen.
This is a female shrub showing seed cones in September. They look like and are often called berries. In fact they are cones but instead of being woody, like most conifers, they are fleshy.
Close-up of Common Juniper “berries”. The arrow shows where 3 fleshy seed scales meet. Note that this type of cone is not like the aril of the Common Yew which has a single fleshy scale that grows round the seed. After the pollen has entered the cone there may a delay before the seed is formed. Cones turn blue when the cone is ready to be eaten by birds which then disperse the seeds in their droppings.