Strongylodon macrobotrys

jade vine

 

Strongylodon macrobotrys

A.Gray 1854

pronounced: stron-GUY-loh-don mak-roh-BOT-reez

(Fabaceae — the hibiscus family)

subfamily: Faboideae - the bean subfamily

common names: jade vine, emerald vine

Strongylodon is derived from the Greek words στρογγυλος (strongylos), round, and οδους, οδοντος (odous, odontos), a tooth; macrobotrys is from μακρος (makros), large and βοτρυς (botrys), a bunch of grapes.

This extraordinary vine is native to the rainforests of the Philippines, on Luzon, Mindoro and Catanduanes Islands, where it is now an endangered species owing to deforestation and the decrease in numbers of its natural pollinators. Known there as tayabak, it is one of the most exquisite of all tropical climbing plants, with its beautiful chains of jade-green flowers hanging in grape-like clusters.

In its natural state, the vine is found beside streams in damp forests, or in ravines, entwining itself through tree branches with the leaves spreading over the canopy. The plant pictured is growing in a Nelly Bay garden, clambering over a tree.

The jade vine was first seen by westerners in the mid 19th century, by botanists who were members of the US Wilkes Exploring Expedition (1838-1842). This expedition explored and surveyed the Pacific Ocean and surrounding lands, and was a major factor in the development of science in the USA, especially in the field of oceanography.

Jade vine is a woody vine with thick stems 2 cm or more in diameter, that can grow to a length of 25 m. The pale green foliage is trifoliate, the leaflets oblong with a mucronate tip, and about 10 cm long, the middle leaflet largest.

The inflorescence first appears as a cluster of buds, which opens into a pendant truss of flowers (known as a pseudoraceme) which can be anything up to 3 m long, depending on how well the rainforest conditions have been replicated. The individual claw-shaped flowers measure up to about 6 cm across, and are designed to be pollinated by bats. The ground beneath the vine is strewn with dropped flowers. These fallen flowers change colour as they dry out, from mint-green to blue-green to purple. If pollination is effected, huge bean-like pods are produced.

Although the jade vine is now a rare sight in the wild, British botanic gardens have had great success in growing it in their greenhouses, and getting the plant to flower. Pollination, however, is another matter. Greenhouses are usually lacking in bats, and the flowers have to be hand-pollinated. In the wild, a bat hangs upside down to taste the flowers’ nectar, and pollen is gently brushed on to the bat’s head while it drinks. When the bat visits another flower, the pollen from the previous flower has to be collected by the flower before the new pollen is brushed on to the bat’s head to be transported elsewhere. This is very difficult to simulate by a human! A Kew gardens botanist named Christina Prychid successfully impersonated a bat in 1995, and pods were produced for the first time in over 30 years. These pods were very heavy, and had to be supported by nets to keep them from falling off the vine before they were ripe.

 

Photographs taken in Nelly Bay 2012, Picnic Bay 2014
Page last updated 11th April 2019