Gunnera identification

[johnw]

Not a medical issue, I wonder if anyone can tell the difference between G. manicata and G. tinctoria.  The leaves - despite being diagnostic - are no help whatsoever for me.  This one is the early flowerer but it's a good month behind this year.

johnw

[Maggi Young]

I can't help... they all look the same to me

Plant List shows different distribution and more than half a century of difference in description... not that that is much help!

Gunnera tinctoria (Molina) Mirb., Hist. Nat. Pl., ed. 2, 10: 141 (1805).
Distribution: Chile to SW. Argentina


Gunnera manicata Linden ex Delchev., Rev. Hort. 39: 219 (1867).
Distribution: S. Brazil

[johnw]

Thanks Maggi. A friend had 3 plants in his yard - one of one species and two of the other. They eventually got about 4 metres high.   You could see the difference at the stage in the photo. Unfortunately he had lost the labels and I stupidly did not photograph them and have only this polaroid I took with his camera.  All his propagations of them looked the same for years. (Posted in 2008 with no responses - surely there's Gunnera specialist in our midst.)

I think the one on the left is the same as the one in the right foreground.


johnw

[jandals]

Hi John . I collect seed of both these species . Fortunately the best way to tell them apart are the seedheads . Your plant is Gunnera tinctoria and your friend has G.manicata behind his left shoulder and G.tinctoria on his right ( I am reasonably sure , its just I can't see the seedheads)
Gunnera manicata has lighter colored and less dissected leaves than Gunnera tinctoria .
The seedheads of G.manicata are more open than G.tinctoria and the lateral branches are longer and smaller diameter .
Check out figures 3 and 4 at http://www.rnzih.org.nz/pages/Gunnera_tinctoria_and_G_manicata.htm
They also hybridise and there are intermediates at the Dunedin Botanic Gardens
They are also a bad weed in parts of New Zealand , which is why they become of interest to me

[johnw]

Jandals - Many thanks for your research and information.  Seems these are very hard to distinguish unless one has the two growing side beside.   With the help of Brian Ellis too the flower heads of mine seems to confirm as you say that it is G. tinctoria - tigher inflorescences and without the spike atop that is mostly branchless.  Let's not even think about the possibility of hybridity!

Should you ever have spare seed of G. manicata...

On another note I wonder if Gunnera magellanica is worth a try here.  Surely it is tougher than these two brutes???  

johnw

[Ulla Hansson]

I have cultivated Gunnera magellanica for many years. They seem to be fully hardy in my climate. It can withstand -18 degrees Celsius without any protection. It can spread fairly well, but is relatively easy to remove.
 I've never seen it set seed.
 Gunnera manicata (I think it is manicata), are much less frost-resistant. It must be covered properly, and it does not help always. The last two winters have been hard at it, at this point is not larger than a Rhubarb.

[johnw]

Ulla  - Thanks for that.  I will have to try magellanica if I see the seeds offered in the seedexs.

Here too manicata and tinctoria must be covered for the winter, straw then a sheet of plastic then more straw.

johnw

[Paddy Tobin]

John, I cannot help with your identification puzzle but can say that G. magellanica grows very well here in the open garden and has been  perfectly hardy in our last two particularly cold winters. It is a far more pleasant plant to deal with than the two giants you wonder about above. I've grown it for many, many years and it is a lovely plant.

Paddy

[FrazerHenderson]

John

You might wish to consider adding the ground-covering Gunnera monoica to your collection. It is, I believe, to be found in New Zealand.

Frazer