A spectacular giant flowering spike which took 20 years to grow has been unveiled by delighted botanists.
Plant bursts through glass house
The Mexican Agave Sisalana is known as the century plant because it blooms so infrequently. And once it does, it dies.
The plant broke through the roof of the Glass House at Cambridge University Botanic Gardens at Christmas and had to be protected against the frost.
Gardeners had prepared to remove the pane of glass as the Agave rapidly approached the roof at a rate of around 5cm a day.
But after returning to work one morning they discovered the central spike which bears the flowers, had reached a height of more than eight feet, smashing the glass as it burst through.
Gardeners used a fleece to wrap up the tip at night to protect it against the winter frosts.
Now that the milder weather of spring has arrived, experts have removed the special polythene casing protecting the spike, to reveal the flowers.
Glass house supervisor Rob Brett said: 'The individual yellow flowers of the plant are fairly small, but they are borne on these amazing spikes that can reach anything up to seven metres in the wild.
'It is fantastic to see something this spectacular flowering here in Cambridge.'
The plant's flowers are a sea-green colour and normally last for about three weeks.
Tim Upton, superintendent at the Botanic Gardens, said: 'Our main concern was to stop it getting damaged by frost and we have wrapped it up in a frost fleece to protect it.
'This is the first time we've had an agave flower for many years.
'There is no record of when the last one was, so this is a rare moment.'
Sadly the plant will die after flowering but off-shoots have already been cultivated to ensure the garden still has a specimen, although staff are not predicting how long it will be before they eventually reach maturity and flower.
The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.