Nature of Corsica 4: Trees and Shrubs

Umbrella Pine, Pinus pinea

With very little level ground for fields, most of northern Corsica that we saw is covered with forest and scrub.  Starting at the coast, on sunny hillsides can be found Euphorbia dendroides, Tree Spurge, the only non-herbaceous Euphorbia native to the mainland of Europe. It has a range around the Mediterranean, but because of its ornamental appearance it has been used in gardens in other parts of the world. As with many such plants, in some places it has “jumped the fence” and become an invasive weed in some places (California for example). This is especially a problem as like all Euphorbias it has a toxic latex and may cause dermatitis in people who come in contact with it

Trees of Bristol: The Ginkgo

 At this time of year, among the fallen leaves can be seen the distinctive fan-shaped leaves of the zoo’s Ginkgo trees. Ginkgos can be seen in many parts of the world today, as they make good street trees. Ginkgos adapt well to the urban environment, tolerating pollution and confined soil spaces. They rarely suffer disease problems, even in urban conditions, and are attacked by few insects. That they are to be seen anywhere however is a major triumph of survival, as Ginkgos are among the oldest living plants.

'Autumn Gold'

For centuries it was thought to be extinct in the wild, but is now known to grow in at least two small areas in Zhejiang province in Eastern China, in the Tian Mu Shan Reserve. These populations may have received at least some assistance by local people in their survival, as ginkgos are often grown in the grounds of Buddhist monasteries.

Prior to their discovery by western explorers of China, Ginkgos were only known to western science as fossils, mostly of leaves. The fossil record of the group reaches back to the Permian period, 270 million years ago, and at their height there were at least 16 genera with a variety of forms. Some were like the trees of today, others were more shrubby and with divided leaves that must have made them look rather like Japanese maples. Their origins are unclear (this is the case with most plant groups), as in some respects they resemble cycads, in others conifers. The mostly likely origin is a group generally referred to as the seed ferns, as they had fern like leaf structures but produced seeds like more advances plants..

'Saratoga'

Trees of Bristol 1: The Whitebeams and others

Outside the aquarium at Bristol there is a small garden containing various rare or endemic plants of the Avon Gorge, among them are several trees, including two endemic forms of Sorbus, the genus that contains the Whitebeams and Rowan trees. The South West of England is a major global centre of diversity in Sorbus, with at least 16 native species plus another two naturalised European forms in the Avon Gorge that runs by the zoo, and more being identified all the time. In addition, more endemic species can be found nearby in north Devon, the Cheddar Gorge, and Symonds’ Yat.