Allium sphaerocephalon or the Bristol onion has a wide distribution through the Iberian Peninsular and Mediterranean region. The only British locality is the Avon Gorge with its sunny rock ledges forming a warm microclimate which has enabled it to survive this far north at the edge of its European range.
Another native to Bristol is Sorbus bristoliensis which grows nowhere else in the world. There are thought to be around 250 trees growing in the Avon Gorge and the garden plays a major role in the conservation of this rare plant.
The lancewood or Pseudopanax crassifolius is a fascinating plant that has two stages of leaf development. When young the plant has linear, bronze, hard edged foliage, giving the impression of wilting, while later, after some 25 years when the plant has gained height and maturity the leaves become green, soft, and shorter with smoother edges. This is thought to be an adaptation to prevent young plants being eaten by New Zealand’s now extinct Moa birds.
Ginkgo biloba or maidenhair tree is the only surviving member of its genus, which is the only genus in its family, which is the only family in its order, which is the only order in its class. This plant is virtually unchanged from fossil records and represents the only living bridge between ferns and conifers. An important traditional Chinese herbal medicine it was first introduced to Europe as an ornamental plant in 1730.
Up until 1994 the Wollemi pine only existed in fossil records dating back 200 million years. Then, a park ranger called David Noble abseiled into a gully in Wollemi National Park in the Blue Mountains of Eastern Australia and discovered a number of trees which had been growing in isolation for millions of years as a relic population.
Native to South Eastern Australia the Banksia is a remarkable plant. After pollination the flowers remain on the tree holding onto the fertilised seed and turning brown. When a bush fire occurs the heat burns the outside of the dead flower heads and they slowly open. After the fire has passed small winged Banksia seeds drift down to the cooling ash, germinate in days before putting on quick growth and regenerating the bush.
Nelumbo nucifera or sacred lotus has deep religious meaning to Hindus and Buddhists as it symbolises beauty and purity with the stunning flower rising out of the muddy shallows. The leaves are water repellent and as the water rolls off it picks up dirt particles keeping the surface of the leaf clean. The Lotus has been in cultivation in China for over 3000 years where it has medicinal, nutritional and spiritual value.
The Venus flytrap is a fascinating plant described by Darwin as “one of the most wonderful plants in the world”. It lives in the poor soil around the edges of South-Eastern USA’s swamplands and has evolved to gain nutrition through flies and insects rather than the soil. Within the traps are three trigger hairs which, if touched more than once in quick succession, will close and slowly digest the insect over a number of days.
The Madagascan periwinkle is a popular ornamental plant but is also credited with raising the survival rate of childhood leukaemia. While studying the anti-diabetic properties of the plant in the 1950s scientists discovered two highly toxic alkaloids called vinblastine and vincristine in its tissues which are now used in the treatment of a number of different cancers.