Dawn redwood - a visitor from the past

I have been thinking about the impact of introduced plants, and this was brought into focus again by the role of gorse in the fire at Owhiro Bay.  Then today I heard an interesting interview with ornithologist and author Glen Chilton about the impact of "alien invaders" - plants and animals introduced for various reasons into a variety of countries.  Amongst other things I learned that a number of African grasses were introduced to Australia (in the 1930's) and that they have intensified the nature, intensity and impact of fires there - which are on a huge and terrible scale compared to the little local fire which set off my musings.  I had no idea!  What a cocktail - flammable native plants plus exotic grasses which greatly add to the risk, intensity and damage caused by fires, and now changing climate and record high temperatures...

Fortunately there are many exotic plants which have not caused problems (so far) and it has been a great joy for me to experience some of them.  One is the dawn redwood - Metasequoia glyptostroboides.  It is often called a "living fossil" because it is a survivor from the Mesozoic era - dinosaur time!  Fossil records show that it was widespread in the Northern Hemisphere then.  It is not clear why a small forest survived - in China, in Lichuan county in southwestern Hubei province.  But it did, and we can experience a connection with that time in the form of this beautiful deciduous conifer.

It was in the 1940's that there was a curious flurry of recognition and discovery for the dawn redwood - Shigeru Miki of Japan reclassified fossils as coming from a separate species which he named Metasequoia, and Chinese foresters discovered unfamiliar trees subsequently identified as of this species, until then considered to be extinct.  In the late 1940's and early 1950's seeds were distributed to arboreta and botanical gardens.  It has proven to be a fast-growing and beautiful tree.  This one in Queen's Park in Nelson is seen in the golden light of a summer's evening.  This emphasises the lovely sculptured trunk, the reddish bark and the very attractive fresh green leaves with the lighter coloured drooping clusters of pollen cones.

It is quite extraordinary to think that this lovely tree links us with the very distant past, when our ancestor mammals were tiny mouse-like creatures - maybe they scurried up trees like this to avoid being squashed by enormous dinosaur feet?