A plant brought to England by the Romans is slowly smothering native bluebell species and experts have warned that something must be done before it is too late.  

The warning has been issued over Alexander - or horse parsley - which grows on waste ground and in hedgerows around Norfolk's rural roads. 

The tall perennial plant is of Mediterranean origin and was brought to England by the Romans who used it as a culinary and medicinal herb. 

It is a member of the carrot family and typically it has long tap roots that easily reach 30cm in depth, making it very difficult to fully move and allowing it to easily propagate across seasons. 

Eastern Daily Press: Alexander has spread all across Norfolk in recent years and continues to proliferate in areas of minimal attentionAlexander has spread all across Norfolk in recent years and continues to proliferate in areas of minimal attention (Image: Poppy Ferrier)

Liam Smith, from the Norfolk Non-native Species Initiative, said: "This year is proving to be a very good year for the plant. 

"There isn't much that can currently be done to control the plant, although it is a topic of concern that hasn’t evaded us. 

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"The plant has become a real issue in recent years and we are working to find a way of preventing its further spread and eventually of tackling it." 

Despite their similarities, Alexander should not be confused with cow parsley which is a very common and recognisable native English plant.   

Like cow parsley, Alexander has insect-friendly flowers in the spring but grows far larger than the native plant and smothers low-lying flowers such as bluebells, which are unable to grow in its shade. 

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The news comes as a concern as the English bluebell is already under threat from the Spanish bluebell. 

Wild plant conservation charity Plantlife has said that Spanish and hybrid bluebells are more vigorous than native species and once out in the wild can cross-breed with the native bluebell, diluting its characteristics. 

In comparison to native bluebells, which have narrow leaves and are deep blue in colour, the Spanish variety has broad leaves and paler blue bell-shaped flowers.