As far as what is Britain's most revered, important and symbolic plant. That would be the "Rose." Mixed color, specifically. Today it is England's official symbol of it's government.
But that might not be the kind of "sacred" you're asking about.
Ancient England held many plants up as sacred. However of the long list the most important and widespread plants considered sacred were the "Poppy" and "Mistletoe Plant"' were probably among the most accepted as being extremely sacred.
shamrock
Cats were sacred in ancient Egypt
woad
Cats were not sacred to the ancient Romans, as they did not worship animals. You are confusing the Romans with the ancient Egyptians, who revered the cat.
yes
The ancient Britons
shamrock
Cats were sacred in ancient Egypt
woad
Hera's sacred plant is the lotus flower.
It means "tattooed"! The immediate meaning of "Brittnee" is "woman of the Britons". The Britons were the ancient inhabitants of Britain. Outsiders called them "Britons" - "tattooed people" - because they painted themselves blue with woad.
The blue dye used by Ancient Britons to paint themselves was called woad. Woad comes from the plant Isatis tinctoria and was commonly used by Celtic tribes in Britain for body painting and clothing dyeing.
Ancient ruins are not sacred because they lost their religious meaning. When we step inside what was one day an ancient temple, we do not have the required belief to make it sacred.
It is reputed to have been used by St. Patrick to demonstrate how God could be three persons in one, by showing three leaves as part of one plant.
The bull is sacred, because it is in the Taurus constellation.
Cats were not sacred to the ancient Romans, as they did not worship animals. You are confusing the Romans with the ancient Egyptians, who revered the cat.
From the latin word 'laurum'=laurel,bay tree, which was a sacred plant for ancient Romans,symbol of glory.An other possible origin is the ancient Celtic 'laur', that means 'sufficient,satisfactory'.