New Zealand field trips June 2010

[David Lyttle]

Just back from Nelson where I gave talks to the Nelson Alpine Garden Society at their Study Weekend at St Arnaud and to the Nelson Botanical Society a week later. This gave me a chance to look around.

1,2,3 View from Spooner Range lookout driving to Nelson City from St Arnaud. The snow covered peaks are the Richmond range to the east of Nelson city.

4 Dun Mountain ultramafic zone. The vegetation is stunted as the soil is infertile and will not support the growth of forest

5 Ultramafic vegetation.

6 Ultramafic outcrop Note reddish weathering

7 Dun Saddle below Dun Mountain

8 Slopes of Dun Mountain

9 Rock outcrop with Totara trees

10 Coppermine Saddle at the head of the Maitai River which flows through Nelson City

[Paddy Tobin]

David,

Great to have you reporting on your ramblings. Could you explain "ultramafic" for me, please. I believe it refers to the rock type  but it is not a term in my common usage.

Paddy

[Maggi Young]

David.... the weather must have been good to you, these pictures look to dipslay the perfact days for photography in the mountains!


Paddy.... I don't know much about ultramafic rocks.... I just  know what I need
to know  about them.... many types of ultramafic rock are gem bearing! 

[Paddy Tobin]

And, diamonds are a girl's best friend!

Paddy

[Lesley Cox]

Along with lilies and poppies.
I bet the Nelson crowd gave you a good time David?

[David Lyttle]

Paddy,

Ultramafic rocks (peridotites)are igneous rocks that are rich in magnesium and iron and tend to have low concentrations of silicon, sodium and potassium. They tend to weather red due to their high iron content. It is thought they are derived from the mantle rather than the crust (eg granites). The high concentrations of magnesium inhibit plants from taking up calcium hence the sparse plant growth in soils derived from them.

Maggi,

If you like you like chromium,copper, nickel and asbestos then peridotites are the rocks for you. But then again you might be looking for pounamu.

Lesley,

I enjoyed my time in Nelson. I was treated very well.

I will continue the posting with some plant pictures. Several of these plants are restricted to ultramafic habitats.

1,2 Wahlenbergia albomarginata subspecies olivina. The subspecies is an ultramafic endemic.

3,4,5 Gentianella stellata Also an ultramafic endemic.

6,7 Pimelea suteri Also confined to ultramafics

8 Huperzia varia A clubmoss

9,10 An unamed species of Melicytus Probably restricted to ultramafic substrates

[Maggi Young]

The various types of ultramafic rocks are valuable for jade (pounamu) deposits but they are also host to diamonds, garnets (including demantoid garnets),olivine (peridot), corurundum (rubies and sapphires- interesting to note that these are found in vermiculite mining areas!)........heck, I'm only interested in the bright shiny ones..... you can keep the asbestos! 

[David Lyttle]

Sorry Maggi,

Not a smidge of anything other than boring old serpentine. You will have to be content with the flowers; violets, gentians, bluebells and daphne.

[Maggi Young]

  David, while it is interesting to know what other delights might arise from such rocks, believe me, your photos of these floral gems is more than satisfying!

[David Lyttle]

Here are a few pictures taken at Pelorus Bridge. The area is notable for a patch of lowland forest that is in fairly good condition. Many North Island species reach there southern limit here: eg tawa (Beilshmiedia tawa) and hinau (Elaeocarpus dentatus).

1,2 Pelorus River and gorge The next pictures are of plants growing in rock crevices in the river bed

3 Hebe stenophylla var stenophylla. I saw better specimens in flower the next day but did not photograph them.

4 Hebe rigidula var rigidula One of the rarer Hebe species.

5,6 Muehlenbeckia ephedroides This is a curious leafless species related to Muehlenbeckia axillaris.

7 A fern Botrychium australe. This is growing in the forest I hope I have identified it correctly. There is a second species Botrychium biforme that has finer leaf segments.

[David Lyttle]

Here are a few fungi; I will post them here however Maggi if you prefer to move them that is fine with me.

The first ten are all various species of Cortinarius. I generally take two picture one of the intact specimens and a second with with an upturned cap to show the stipe and gills. In local mycological circles this is called the dead rat shot.

[David Lyttle]

Here is the next set again they are all species of Cortinarius

[David Lyttle]

A few more but more variety this time

1,2 Cortinarius

3,4 Cortinarius porphyroideus syn Thaxterogaster porphyreus. This lovely violet fungus is quite unmistakable.

5, 6 An Amanita Amanita nothofagi (I think)

7 An orange coral fungus

8 A green Hygrocybe

9 Dont have a clue but it looks spectacular

10 Mycena sp

[Maggi Young]

The variety of these funghi is terrific, David. Would you know if any (I'm thinking particularly of the red and purple ones) can be used for dying  purposes? They look likely candidates for a bit of home wool-dying to spice up the knitting or weaving of some enterprising craftsperson.

[Lesley Cox]

The violet species, if you're interested in bright and shiny stones Maggi, beats amethysts any day.