Gunnera but which? Manicata or tinctoria; was stumper: seen around town now

This is only a marginally legal posting - I do know the genus, but not the species. They're popping up now in parks and gardens. It's so exciting to see them.

 

Re: seen around town now

Hmmm!
Left it a week hoping for inspiration.
None came.
Seems everyone else is in the same position!

Time for help. A clue or something.
Is it a tree, shrub, or perennial... what has got you excited?
Help!

 

Re: seen around town now

Sorry, I can't post any other bits until I get home next tuesday. It's from the tip of a large inflorescence of a plant that people always remark on once it returns in the spring.

Thanks for mentioning your interest.

 

Re: seen around town now

Gunnera?

 

Re: seen around town now

Yes, it is Gunnera. I can post other photos next week. I can't run the contest to identify it any further than that, since I don't know the species, so Lysichiton, you win.

 

Re: seen around town now

wcutler......Now you have to do YOUR homework to work out whether it is Gunnera manicata or Gunnera tinctoria!

Years ago we went round a very good small nursery and found this dear creeping wee plant called Unnera prorepens. We asked about it... only to be told they had missed the G from the label ... it was Gunnera prorepens! Duh!

http://www.google.co.uk/search?q=Gu...&source=og&sa=N&hl=en&tab=wi&biw=1276&bih=537

Since then we have always called them all Unners!

 

Re: seen around town now

I love the look of that "Unnera" prorepens. Have you seen it available here recently? Are there any in the collections of UBC or Van Dusen gardens?
Did you buy one yourself, and if so how well has it done here? Is it invasive? My back yard is very soggy and it sounds like it prefers damp conditions so I'd love to give it a try if I can find one.

 

Re: seen around town now

I'm sure most garden centres have Gunneras...great big ugly brutes with inflorescence like some Sci Fi pineapple on drugs & leaves like golf umbrellas (very useful in cold, damp BC). I hope your soggy yard is a really big one. :)

...oh sorry, that was Unneras we were talking about - they're the little creeping guys. We had some but got rid of them after they strangled the neighbour's cat.

 

Re: seen around town now

Well, I've done some homework but I can't tell. Apparently, I'm in good company on that score. Here are the photo the original posting was taken from and another of the inflorescence.


The Royal New Zealand Institute of Horticulture has quite a detailed comparison page of G. manicata and G. tinctoria. It indicates that G. manicata should have a longer, narrower inflorescence, but then shows a photo that seems to demonstrate the opposite.

It says the leaves of manicata are supposed to be "broader in proportion and have a flatter surface to the blade". Some of these leaves are flat and others not, but they're emerging leaves, so they might flatten out more. I don't know these people but they agreed to help me out with a height reference I could post. Well, mom agreed. Daughter wasn't so sure. These photos were taken today, two weeks later than the inflorescence photos.

The G. tinctoria rhizome is supposed to be much longer. These seem pretty long, but I don't have other photos for comparison.

The same page says that a better distinguishing feature is that "[FONT=Arial, Helvetica, sans-serif][/FONT]n G. manicata there is a prominent development of membranous "webbing" between the main lobes of the scale whereas in G. tinctoria this is not well developed and so the lobes are often almost free to the main rachis of the scale." Are we looking at webbing?


I see that G. tinctoria has been a POTD feature. Douglas Justice in a comment mentioned this one having shorter, stiffer inflorescence branches, and leaves that are "a mere 1.5 m", which is about the size of these leaves, though again, the leaves are new. This plant definitely has short stiff inflorescence branches, at least at this stage.

I'll guess G. tinctoria.

[Edited]I forgot to add that I remember David Tarrant telling us on a tour that he was told when he was young that Gunnera ate bad little boys. Seems likely enough.

 

Re: seen around town now

I thought it was the other way round?? "Edible Parts: Stem. Young leaf stalks - peeled and cooked as a vegetable or eaten raw" ;-)

In Britain, they are usually called 'Gunnera manicata', but it'd stand to reason that the hardier Chilean G. tinctoria would actually be the more successful, with perhaps many plants mislabelled.

 

Re: seen around town now

Well, G. manicata is the dominant Gunnera here, and I can tell you from your photos that those ain't them. The most striking feature I've noticed between the two species is that on G. manicata, the new leaves come out red. See below - this is a confirmed specimen from the Quito Botanical gardens.

 

Re: seen around town now

Sunburn?
Great photo, lorax. You're saying you've seen G. tinctoria in a similar location to the manicata and its leaves come out green? Seriously, that's a pretty easy identifier. If that were the case in most places, wouldn't it have been mentioned somewhere? Maybe where a lot of people grow manicata, there's little sun when the leaves emerge and they're green?

Instead I'd been looking around for scales and webbing where the leaf joins the stem. I think I'm seeing G. manicata webbing in this photo from this Plantes-extraordinaires page with several other photos. I don't understand the bit about scales.

 

Re: seen around town now

I think the threat would be equally effective either way. :)

 

Re: seen around town now

But not one I'd think reliable; anthocyanin content in plants is generally very variable from one individual to another, and I'd be very dubious about using it as a species discriminant.

 

Re: seen around town now

I went to VanDusen today to see if they had G. manicata. The gardener Egan told me he thought the ones I photographed here are that species, but that Douglas Justice has told him he thought they were G. tinctoria, so now Egan is not sure. I would be able to stand up under one of the leaves, and one leaf I measured at approximately ninety inches across, or 2.2m, and these are still young leaves.

I don't see any webbing on these either, not that I know what that would look like. I'd really like to see what the scales and webbing look like on G. manicata, but I don't know where to go look or where to find a photo that demonstrates that.

Some of the inflorescences were much larger than the others I photographed. Egan said they're all from this year, not old ones from last year. The book height (or width as used here) is 21.5cm.



This gunnera is one Egan thought would be G. tinctoria. It's quite a bit smaller than the others on the pond. I couldn't get up close to it.


Egan also showed me another Unnera: G. magellanica.

 

Re: seen around town now

I have long stuggled to tell Gunnera manicata and Gunnera tinctoria appart.

In The Botanic Garden. Perennials and Annuals,by Roger Phillips and Martyn Rix.

It states that "Gunnera tinctoria is smaller and has more lobed leaves than Gunnera manicata."
also

"Gunnera manicata leaves can grow grows to 3m across. on stalks over 2m tall"

In Cornwall, Trebah gardens has a forest of Gunnera manicata.

http://www.cornwalls.co.uk/photos/img2364.htm

http://www.trebahgarden.co.uk/garden/gunnera-passage.html

Unnera magellanica ( Gunnera magellanica to everyone else),should be sold with a health warning. It only grows a few inches tall, but it sure does spread. A small thug.

 

Re: seen around town now

I agree with Egan, the ones in the first few pictures of post #15 are Gunnera manicata.

A relative's garden has a G. Tinctoria that only just survived this last winter (coldest for 30 years) after we forgot to cover it with the dead leaves like we usually do. I will try and take a photograph of the part of it that survived, but there may only be leaves this year, not flowers.

 

Re: seen around town now

Ok, here is a picture of G. tinctoria, sorry for the bad quality, I forgot my camera so I took it with my telephone and the light was poor:


It matches the smaller gunnera Egan identified as G. tinctoria.

When I have visited gardens in the UK that have old established plantings of gunnera it is nearly always G. manicata. These plantings are usually in areas where lack of space would not be a concern, so they have gone for maximum impact by planting the clearly much larger species. I don't know if there is a significant difference in cold hardiness between the two species when talking about established mature plants, but there may be for seedlings and young plants.

Some differences I have observed:

Manicata is much larger in scale than tinctoria.
The manicata flower spike looks more like a bottlebrush than the more compact tinctoria spike does.
Manicata has much longer leaf stalks than tinctoria.
Manicata leaf stems are usually more upright than tinctoria.
Manicata tends to hold its leaves more horizontal than tinctoria.
Leaf stems are more likely to be greenish in manicata and reddish/brownish in tinctoria, but this is somewhat variable and there can be overlap.
(The prickles on the stems seem smaller relative to the stem diameter in manicata, and also more numerous and more evenly sized and regularly spaced. Not 100% sure on this last one, need to check more plants.)

BTW I did not have a clue the original picture was a gunnera when I viewed it a couple of weeks ago.

 

Re: seen around town now

May be a bit more complex than just 2 species of large-leaved Gunnera spp. . . seems there's 14 of them:

— Williams et al., Gunnera tinctoria: biology, ecology and conservation impacts in New Zealand (2005).

 

Re: seen around town now

This one surprises me, especially seeing lorax's photo.

I guess I'm going to have to check all these in a few weeks to see how big they've gotten. Other than the elusive webbing, everything else seems so much a matter of degree, with the original plant falling between the other two posted ones. Thanks, everyone. I'll be back.

 

Re: seen around town now

I was afraid of that. OK, I've looked them up. It surprised me how many of them are the little runner Unners: prorepens, magellanica already mentioned, and albocarpa, hamiltonii, densiflora, dentata, flavida, kauaiensis,and monioca.
Perpensa leaves are 6-10 inches, so that's out.

Masafuerae seems too large to consider, which should rule out magnifica, which I saw somewhere had the largest leaves. Petaloidea has some petal-looking bract sort of stuff. That's out.

Well, that's the Wikipedia list. We're back to our two culprits.

 

Re: seen around town now

I think most, or at least many, of the other large leaved species would not be hardy in a UK or BC type climate. Many are described as coming from such environments as Columbian rainforests or Pacific islands that rarely, if ever, see frost. G. tinctoria and G. manicata have a reputation as the most hardy types, but it is possible that some rarer species could be equally hardy.

I wonder if it is possible for G. tinctoria and G. manicata to hybridise, resulting in offspring with intermediate characteristics?

 

Re: seen around town now

I don't think it's sunburn. Both G. manicata and G. tinctoria grow along the cloud forest biodiversity corredors that I frequent, and I can tell you right now that those are areas that don't see a whole lot of direct sunlight, ever. The altitude's reasonably high (1800 meters seems to be where the Gunneras stop), and the cloud cover is almost constant. Growing side by each, as they often do, I can tell you that only G. manicata has red new growth, and G. tinctoria is green. The particular specimen I photographed at the Quito Botanical Gardens was in the temperate orchidarium, which is at an elevation of 2800 meters above sea level and which is roofed to simulate the cloud cover typical of cloud forests.

However, as Michael F points out, anthrocyanins are variable.

Maybe it's a soil thing? I'm pretty sure y'all up there aren't simulating cloud forest leaf mulch and loam for your plants.... They do at the QBG, though, because the other things growing in that area of the gardens wouldn't survive otherwise.

 

Re: seen around town now

Here is a good comparison shot of the inflorescences from Auckland Council: http://www.arc.govt.nz/albany/app_templates/pagelets/mainarc/plants/PlantsImage.cfm?imgId=1174 They are easy to tell apart when you can see them side by side at the same stage of development.

They also have some decent photos of each species on the pages for Chilean rhubarb (Gunnera tinctoria) and Giant rhubarb (G. manicata).

 

Re: seen around town now

No they are not easy to tell apart from the photos. For one thing, the same plant has bits that look like each of those photos. What about these ones, for instance? I think these are two different plantings. I'm starting to lose track now, but all of these look the same to me.


Also, I can't tell the size from those photos. All the ones I've photographed now have some leaf stalks 2m high and some flower stalks as tall as 1m or more, with some leaves about 1m on each half. Here are some from the Stanley Park Rhody garden. I was trying to show how thick the leaf stalk is, and the flower stalk is about twice the 21cm book height to the first of the whatever those things are called (was that an indicator of something, or just the whole stalk length?).


For the record, the Parks Board has some web pages on what's blooming in the spring months in the Rhody garden, and on the early May page, it lists Gunnera manicata. They include a comment that "it can grow up to three metres tall with leaves just as wide, before the end of summer".

Here is the original planting again. I think it looks just like the others.


I still wish I could find something to demonstrate the supposedly distinguishing scales and webbing. Not seeing anything like that is almost all that's keeping me from thinking these are all G. manicata. And lorax's statement that there's no way they are. lorax, have any of the later photos changed your mind?

maf, no-one seems to have seconded your hybrid suggestion.

Now I'm really keen to see UBCBG's.