A touch of the tropical
While over-wintered broad beans and early-sown pea shoots are emerging on allotments everywhere and Wisteria vines are clothing brick walls in blue or white drapes, a quite different member of the vast and economically important Fabaceae plant family is the showstopper in the Botanic Garden's Glasshouse Range this month.
The Jade Vine (Strongylodon macrobotrys) is a tropical, climbing relative of garden favourites in the Fabaceae (or pea) family, which include beans, peas, sweet peas, Wisteria and Laburnum. It has formed a dense lattice of branches in the canopy of the Glasshouse Range from which up to 100 racemes extend down and form a thick curtain that visitors must (carefully) push through to continue on their journey through the Cambridge tropics! We have one of the best-flowering specimens in UK cultivation, with each purple raceme stem supporting many cartwheels of the sensational, almost neon, blue-green flowers that give rise to the common name of Jade Vine.
In its native Philippines, the Jade Vine reaches more than 20 metres in height and is pollinated by bats! It is thought the bats are attracted by the luminosity of the flowers in the tropical twilight, and they hang upside down on the raceme stalks to gorge on the vast quantities of nectar in the flowers. With the flowers dangling down to eye level in the Glasshouse Range, the rich sticky nectar can be easily seen and a close-up inspection of the claw-like flowers reveals the floral similarity between this spectacular tropical liana and the peas and beans we are more familiar with.
In the wild, the Jade Vine is considered vulnerable to extinction due to extensive deforestation, so do come and enjoy this extraordinary plant at its flowering peak this month.