2 May 2018

Plant grown from 203-year-old seed begins new life in the Temperate House

The re-opening of the Temperate House sees the oldest Victorian glasshouse restored to its former glory. But it’s not the only thing that’s been given a new lease of life.

By Anthea Gordon

Leucospermum conocarpodendron

Longest-living seeds 

This Leucospermum conocarpodendron subsp. conocarpodendron was grown from seeds over 200 years old – among the longest living seeds ever. 
It was recently planted in the Temperate House, ready for the opening on 5 May. But the plant’s history stretches back much further than this new home. 

Seeds found within wallet 

The seeds were tucked away in a red leather-bound wallet from 1803 until 2005. A researcher discovered them unexpectedly, while looking into the High Court of Admiralty Prize Papers in the National Archives. 
They weren’t the only seeds found. In total, there were 40 seed packets in the wallet, each labelled with species annotations. 
Some labels were more mysterious, with one listing simply: ‘Seeds from a tree with crooked thorns’. 
The wallet also contained Chinese silk, an envelope with a lock of dark hair, and a prayer written in the centre of a flower cut out from paper. 

Sprouting seeds 

The seeds were brought to Kew, conveniently very close to the National Archives. 
Scientists at Kew tried to germinate the seeds, based on the knowledge that they were from the Cape Region of South Africa. Germination tests included treating the seeds with liquid smoke to replicate the wildfires which enable seed germination in several species from the region. 
They had initial success with three species, labelled as: ‘Liparia villosa’, ‘Protea conocarpa’ and an ‘unknownMimosa’. 
Using the International Plant Names Index, scientists traced their likely modern botanical names to identify the plants. They found that ‘Protea conocarpa’ was in fact a Leucospermum. 
Out of eight Leucospermum seeds, only one germinated – the one that survives today. 
Once germinated, the plants were grown in pots. Only the ‘unknown Mimosa’ (an Acacia), and the Leucospermum survived to maturity. 

Scientists were then able to identify it as a Leucospermum conocarpodendron subsp. conocarpodendron.  
Since then, the plant has grown significantly and is still flourishing. 

Journey of the Leucospermum 

March 1803 – Seeds found by Jan Teerlink in Cape Town, South Africa. They were kept, alongside Chinese silk from Teerlink’s earlier trip to China, in his red leather-bound wallet. 
1803 - Jan Teerlink’s ship Henriette captured on the way back to Holland from Cape Town. 41 packets of seeds were among documents and items found on the ship. 
1803 – Seeds kept in the Tower of London 
1857 - Seeds moved to Chancery Lane 
1996 – Seeds stored in National Archives 
2005 – Seeds discovered by researcher Roelof van Gelder 
2006 – Seeds germinated by scientists at Kew’s Millennium Seed Bank 
2018 – Leucospermum conocarpodendron subsp. conocarpodendron planted in the Temperate House 

Oldest plants in the world 

See how the 200 year old Leucospermum conocarpodendron compares with some of the other oldest recorded seeds:  

  • Seeds from a Persian silk tree (Albizia julibrissin) were stored for just under 150 years in the British Museum. That is, until they got an unexpected watering in 1940 when a fire was extinguished. After this, several seeds – each at least 147 years old – began to sprout. 
  • A 600-year-old ceremonial rattle from Argentina contained seeds that were germinated successfully after being removed from the rattle.  
  • One of the oldest recorded seeds that germinated is an Indian or Sacred Lotus from China. It is thought to be over a whopping 1,288 years old. 

Survivor seeds 

It is known that Leucopsermum seeds can survive in soil for around 80 years. This Leucospermum conocarpodendron subsp. conocarpodendron survived in conditions that were both cooler and more humid than usual, and for more than 100 years longer than had previously been expected. 
This makes Leucospermum conocarpodendron subsp. conocarpodendron a real survivor. 

See the historic Leucospermum 

You can find the Leucospermum conocarpodendron in the Africa section of the Temperate House, alongside other plants from the region from turquoise hyacinth to Aloe jucunda

Daws, M.I., Davies J., Vaes, E., van Gelder, R., & Pritchard, H.W., Two-hundred-year seed survival of Leucospermum and two other woody species from the Cape Floristic region, South Africa. Seed Science Research. 62: 73-79. Available online 
National Archives catalogue