August is holiday time and it seems that everybody has been travelling. I was no exception having planned a getaway to North Carolina a state on the eastern coast of the USA. The state is situated along the Appalachian mountains which run like a spine down the eastern seaboard of the country from Maine down to Georgia. Anybody familiar with the work of Bill Bryson will have read his hilarious account of hiking the Appalachian Trail.
North America has a huge range of conditions from arctic to subtropical and climate is the main factor covering their distribution. Altitude and land mass are also important as the same trees that can be found growing high in the Appalachians can grow near sea level in Canada whilst the Great Lakes create a warmer climate than if the area were all land. Similarly atmosphere also affects habitat, whilst some trees can tolerate extreme aridity others require more rainfall or humidity.
North Carolina is extremely fortunate in having over six hundred species of native trees, shrubs and vines as well as countless herbaceous species which thrive in the diverse climate from mountains to piedmont to coast. The large
forests are mixed with coniferous and deciduous species. When I was there this year I was immediately impressed with the large numbers of walnuts which we some of the most visible trees owing to the large fruits that were held dangling from the branches. The most common species was the black walnut (Juglans nigra). The leaves one to two foot long divided into leaflets which are smooth above and hairy below. The large fruits were two uncles in diameter green on the outside, with a yellowish husk that stained hands and fingers like tobacco. The trees were between 60 and 100 feet high and grew plentifully. Many of the trees I saw were home to tent
caterpillars. What at first I took to be spider webs was the home of these caterpillars, six species of which occur in North America. They are a social caterpillar building nests from silk which hang in the branches of trees. They are often considered a pest because they can defoliate an entire tree. Though I am no expert they looked like Malacosoma americanum as well as something from a horror film!
Another recognisable species which abounded in impressive stands was that well loved denizen of gardens and parks the tulip tree (Liriodendron tulipifera). Growing as they did in close proximity to other trees they had not developed the large rounded crowns that you see in our gardens and parks. Nevertheless they were impressive at 80-100 feet tall though they can reach 150 feet. Numerous seedlings sprouted up wherever you went waiting for an older tree to fall so they can shoot up. Many of the most impressive of
North Carolina’s native trees are chronicled by the Archangel Tree Archive which is worth looking at.
As in many deciduous forests spring is one of the most colourful seasons and the large areas covered by Rhododendron catawbiense hinted at what must be a spectacular sight when the purple flowers emerged. They formed dense thickets with large glossy leaves that were impressive even out of flower.
Beneath the shrub layer many other plants abounded in the moist humus rich medium decomposing on the forest floor. I was struck by the preponderance of trillium though alas too late for flowers! I could also see Paris plants made obvious by the whorl of leaves clasping the stem. Some were beginning to ripen their fruit capsules. All in all it was a fantastic visit to one of the most bio diverse areas of the world.