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New species of the genus Utricularia - Utricularia cornigera


agamemnon

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Hi,

it is not a hybrid, appears to be "problem with mixed herbarium items" in a Monograph by Prof. Taylor (1989) at the species Utricularia reniformis from multiple areas and up to now showed that they are two completely different species (germination of seeds, the seeds, flower)

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Very interesting. I've actually been thinking of buying U. reniformis, but now I'm not quite sure what I'd be getting! Of course it's likely that growers have been unwittingly interbreeding the two types not realising that they're actually different species, so some U. reniformis in cultivation might actually be hybrids between U. reniformis and U. cornigera.

The robust specimens from Serra dos Órgãos, the ones that are probably actually the new species U. cornigera, certainly seem to deserve to be called emergent aquatics since they seem to be able to produce bladder traps that are highly specialised for semi-aquatic environments as well as their usual underground traps.

It would be interesting to know exactly how the U. reniformis cultivars 'big sister' and 'enfant terrible' are related to the wild populations in the study (the two types are very different from one another). This link has a discussion of the two forms with pictures and both - including a photo of a 'big sister' plant from Serra dos Órgãos. So 'Big Sister' might very well be U. cornigera.

http://www.carnivorousplants.org/cpn/Speci..._55.html#sister

Cheers,

Tim

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Hello everyone,

Thanks for the article link Bob! It could well be that the new species U.cornigera was sitting "under our noses" for a long time -- that's usually the case with most new species that are "discovered". But I can't say I really buy the leaf morphology/ texture/ size as an important character, since this is such a widespread and variable species. Notice that he is only comparing populations fro 3 places: Serra dos Órgãos, Itatiaia and Campos do Jordão!

Although, Studnicka did great work studying the seed germination and morphology, he seems to have ignored the possibility that the U.reniformis from the Serra dos Órgãos is not a new species, but possibly a hybrid with U.nelumbifolia. The seed and germination characters of his U.cornigera fit very nicely a hypothetical hybrid scenario, being nicely intermediate between U.reniformis and U.nelumbifolia. U.nelumbifolia is abundant on the Serra dos Órgãos, but it is not present on the Serra da Mantiqueira, nor does it grow near the type location of U.reniformis at the Serra do Caraça.

In cultivation, I don't believe this "U.cornigera" is common and I believe most people grow something closer to type U.reniformis. For reference, see below several flowers of U.reniformis, including from Itatiaia and Campos do Jordão (taken while I was with Studnicka, both mentioned in his article) and "U.cornigera" from the Serra dos Órgãos (taken a few days before/after Studnicka went there).

"U.cornigera" Serra dos Órgãos, Rio de Janeiro:

UreniformisPedradoSino11.jpg

U.reniformis Itatiaia, Rio de Janeiro/ Mina Gerais/ São Paulo border:

Ureniformis32Itatiaia.jpg

Ureniformis08Itatiaia.jpg

U.reniformis Campos do Jordão, São Paulo:

UreniformisCJordao03.jpg

U.reniformis Serra do Quiriri, Santa Catarina/ Paraná border:

UreniformisSerradoQuiriri05.jpg

U.reniformis Serra do Corvo Branco, Santa Catarina/ Rio Grande do Sul border:

UreniformisSerradoCorvoBranco5.jpg

And here's a pic of type U.reniformis at the Serra do Caraça, Minas Gerais:

ph-10351.jpg

Here's U.nelumbifolia in cultivation (I can't remember if it's from the Serra dos Órgãos or from the Serra da Grama):

IMG_4750.jpg

U.nelumbifolia at the Serra da Grama, Minas Gerais:

ph-10342.jpg

Best wishes,

Fernando Rivadavia

Edited by Fernando Rivadavia
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Hello,

Thanks for pointing out that article, which includes interesting information and illustrations of two different U. reniformis. However I fully agree with Fernando that we are most likely not dealing with two distinct species here, but with one variable species, which displays a great morphological variety across its range, and which is very likely to form stable natural hybrids when growing sympatrically with related species (eg. U. nelumbifolia, like Fernando mentioned. I assume U. geminiloba could be another good candidate, as some of the "small forms" of U. reniformis do not show the typical smooth waxy cover of the upper leaf surface, but rather have glabrous leaves (which are not water-repellent, as in the "big forms").

The problem is that all hybrids of the section Iperua (as well as those of the related Orchidioides) that I am aware of are not sterile, but fertile and able to reproduce. Moreover all species of Iperua have a very similar floral colour pattern, thus are likely to be visited all by similar pollinators. Thus these large-flowered Utricularia species are predestined to form hybrids or even hybrid swarms where more than one species occurs.

In my opinion, splitting a single taxon from the U. reniformis-aggregate, that's a little bit like describing a single location "form" of P. moranensis as a different species ;).

All the best,

Andreas

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Hello Anreas,

>In my opinion, splitting a single taxon from the U. reniformis-aggregate, that's a little bit like describing a single location "form" of P. moranensis as a different species ;).

Good example, since different P.moranensis forms may be the result of hybridization with local species!

Either way, Studnicka raised an important flag here which will hopefully be investigated further someday by someone who can compare multiple populations and do some sort of genetic investigation into possible hybrid origins.

All the best,

Fernando Rivadavia

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Yes, indeed a good example. Moreover i would like to wish the person a lot of "fun" that decides to work on P. moranensis, im sure that it will cause a lot of headache by that huge amount of variety, but i hope it will be done somewhen, also with other species like P. esseriana (maybe of hybrid origin?).

Anyway, thanks for sharing the article. I find this particular Utricularia (new species or not) really beautiful.

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Ah, one more comment I forgot to make: sad that the holotype of U.cornigera was not deposited in Brazil, nor any isotypes...

If it helps future researchers, I do have a herbarium collection from the same spot where Studnicka studied U.cornigera (a day before I was there, I believe, we even photographed the same flowers), deposited at the University of São Paulo herbarium (SPF), which could be used as a reference:

------------------------------------------------------------------------------------------------

BRASIL, Rio de Janeiro, Município de Teresópolis, campos de altitude beirando a trilha para a Pedra do Sino, Parque Nacional da Serra dos Órgãos, c.2120m alt., 13/Nov./2005, F.Rivadavia et al. 2124 (SPF)

------------------------------------------------------------------------------------------------

Best wishes,

Fernando Rivadavia

Edited by Fernando Rivadavia
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Fernando - thanks for all of the pics. I do love Iperua flowers and the 'new' species (whether new or not) is especially beautiful!

Although, Studnicka did great work studying the seed germination and morphology, he seems to have ignored the possibility that the U.reniformis from the Serra dos Órgãos is not a new species, but possibly a hybrid with U.nelumbifolia. The seed and germination characters of his U.cornigera fit very nicely a hypothetical hybrid scenario, being nicely intermediate between U.reniformis and U.nelumbifolia. U.nelumbifolia is abundant on the Serra dos Órgãos, but it is not present on the Serra da Mantiqueira, nor does it grow near the type location of U.reniformis at the Serra do Caraça.
Very intriguing conjecture. It would be interesting if the original author considered this option, and if so, what factors led him to discount it?

If I read it correctly on the CP Listserver, Greg Bourke has both crosses growing in his collection and they have retained the U. nelumbifolia aerial stolons. Would this characteristic have disappeared w/ additional backcrossing or ...?

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Hey Ron,

Backcrossing with U.reniformis (from a simple reniformis X nelumbifolia hybrid) is a possibility for U.cornigera, or even selfing of the original F1 which resulted in an unequal mix of the assumed parental genomes. And it is not at all clear yet if U.cornigera produces aerial stolons or not. Maybe it's ecologically induced and Greg allows his to dry out more?

Best wishes,

Fernando Rivadavia

Edited by Fernando Rivadavia
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Hi guys,

Below are photos (I hope! been a while since I've uploaded anything here) of the hybrids stolons and both species. Note that the hybrid's stolons are intermediate to either parent. I've only posted pics of U. nelumbifolia x reniformis as the reverse cross has been lost.

The trap morphology possibly assists in confirming the new species as a new species with the hybrid having long antenae on its traps. Sorry I don't have a microscpoe so have just taken this shot with my camera. Not very clear but it tells the story.

I don't know the origin of the U. reniformis used for the hybrid but I have been cultivating this clone for roughly 20 years.

Cheers

Greg

U. nelumbifolia x reniformis

IMG_9005.jpg

IMG_9007.jpg

IMG_9003.jpg

IMG_9001nelumbifoliaxreniformis.jpg

U. nelumbifolia

IMG_9010.jpg

U. reniformis

IMG_9012.jpg

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Hello Greg,

Thanks so much for taking the time to photograph your plants and especially the trap!

The trap morphology possibly assists in confirming the new species as a new species with the hybrid having long antenae on its traps. Sorry I don't have a microscpoe so have just taken this shot with my camera. Not very clear but it tells the story.

IMG_9001nelumbifoliaxreniformis.jpg

Quite the contrary! Your pic shows 2 antennae pointing away from the trap, which is similar to what Studnicka reports for the "aquatic" traps of his U.cornigera, see image below from his paper:

Fig6.jpg

The "terrestrial" traps of U.cornigera have short antennae:

Fig5.jpg

While the antennae of U.reniformis from Serra da Mantiqueira have traps with long antennae bending backwards:

Fig4.jpg

Fig3.jpg

To me this only confirms the possibility that U.cornigera is a hybrid. But it also really makes me wonder how variable the traps of Utrics are. Has anybody truly investigated this yet, comparing a single species across populations, habitats, and stages of life?

In fact, looking at Taylor's Utric monograph, things becomes even more confusing. U.reniformis is shown with traps that have antennae neither curved completely inwards nor pointing straight out:

IMG-1.jpg

U.nelumbifolia is the one that supposedly has traps with antennae curved and pointing backwards:

IMG_0002-1.jpg

Short antennae, similar to U.cornigera's "terrestrial traps" are found in the closely related U.nephrophylla and U.geminiloba:

IMG_0003.jpg

IMG_0004.jpg

It seems that the data is simply insufficient for any conclusions to be made at this point...

Best wishes,

Fernando Rivadavia

Edited by Fernando Rivadavia
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Quote: "But it also really makes me wonder how variable the traps of Utrics are. Has anybody truly investigated this yet, comparing a single species across populations, habitats, and stages of life?"

Hi Fernando,

I think that's a good point about the variability of bladder traps within a species or even a plant. In the report about U. cornigera the author says:

"plants from SO [ie. U. cornigera] have very short antennae in the underground traps of diverse

shape, which do not extend far to the stalk."

It's a little bit ambiguous and I'm not sure if he means it's the bladders that are of diverse shape or (less likely) their antennae; nor whether he means this variation is found in individual plants or just within the population at SO. But either way it seems that bladders can be vary variable, even when there isn't true dimorphism between underground and aquatic traps, which there is with U.cornigera. I'd have to agree that defining differences between species based on their traps is probably unreliable.

On the bright side, of all the traps in the pictures, U. cornigera seems to be the only one with straight antennae, which strikes me as a 'pure' characteristic which is unlikely to be the result of hybridisation, especially between species that have curved or even swept back antennae. So ironically, of all the 'species' discussed I think U. cornigera is the LEAST likely to be the result of hybridisation.

Cheers,

Tim

Edited by Tim Caldwell
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Just as an afterthought, I would think that any Utric species that has evolved to produce both underground and aquatic traps might be expected to have longer antennae on the aquatic traps. When you look at closeup photos of bladder traps it's usually possible to tell whether the species is terrestrial or aquatic just be the antennae. Aquatic species tend to have long, slender, elaborate antenae, while those of terrestrial species have much shorter, thicker ones. The antennae obviously perform various useful functions, but are probably much less useful in underground traps that are closely boxed in by compost.

Cheers,

Tim

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Hey Tim,

It's a little bit ambiguous and I'm not sure if he means it's the bladders that are of diverse shape or (less likely) their antennae; nor whether he means this variation is found in individual plants or just within the population at SO.

I think what he means (and shows in his pics) is that the disposition & length of the antennae are different, not the trap shape. Furthermore, his studies are based on plants in cultivation, and not on actual specimens at the Serra dos Órgãos. So there is always the question of whether or not in nature they act the same. Not to mention that the he doesn't mention if the seeds studied came from cultivated plants or directly from the wild. Either way, who can guarantee that the seeds are not the result of a "lucky" U.reniformis flower that was cross-pollinated with U.nelumbifolia pollen? More seeds would have to be studied in situ.

But either way it seems that bladders can be vary variable, even when there isn't true dimorphism between underground and aquatic traps, which there is with U.cornigera. I'd have to agree that defining differences between species based on their traps is probably unreliable.

Trap morphology overall does seem to be a good taxonomic character in Utrics, but I'm simply questioning whether they're as uniform as we are led to think from published work. If leaves can have very different shapes & sizes depending on ecological conditions like sunlight exposure and soil conditions, then why not some variability in traps as well (which are modified leaves, don't forget)?

I guess the question is not so much if there is really dimorphismin U.cornigera (antennae length), but is it truly unique? Is there such dimorphism in U.reniformis as a whole and even in other Utrics? What would we find if we looked at trap/ antennae morphology in U.reniformis from different populations, studying both the traps found in the soil and those on stolons that are coming out the bottom of the pots into the water tray beneath?

On the bright side, of all the traps in the pictures, U. cornigera seems to be the only one with straight antennae, which strikes me as a 'pure' characteristic which is unlikely to be the result of hybridisation, especially between species that have curved or even swept back antennae. So ironically, of all the 'species' discussed I think U. cornigera is the LEAST likely to be the result of hybridisation.

Maybe you did not see the antennae in Greg's nelumbifolia X reniformis picture above, but they are sticking straight out from the trap, similar to those of U.cornigera. Also, notice how in Taylor's drawings of both U.nephrophylla & U.geminiloba there is a simialr dimorphism in the antennae disposition. Maybe Taylor would've found more variability in trap shapes of U.reniformis and U.nelumbifolia if he had looked at terrestrial versus aquatic stolons. (In the case of U.nelumbifolia, which only grows in bromeliads, we'd have to compare traps in stolons in the aquatic medium in the center of the bromeliad versus traps on stolons in the drier medium around the base of the bromeliad rosette, where the leaves are dying out.)

Just as an afterthought, I would think that any Utric species that has evolved to produce both underground and aquatic traps might be expected to have longer antennae on the aquatic traps. When you look at closeup photos of bladder traps it's usually possible to tell whether the species is terrestrial or aquatic just be the antennae. Aquatic species tend to have long, slender, elaborate antenae, while those of terrestrial species have much shorter, thicker ones. The antennae obviously perform various useful functions, but are probably much less useful in underground traps that are closely boxed in by compost.

Maybe all terrestrial Utrics have slightly different antennae disposition if the traps develop in water rather than compressed in soil. Or maybe it's not even due to the different medium, but to different light exposure when in water (brighter) versus soil (dark).

Either way, what I'm trying to say is: I don't think there is enough information for any conclusions yet. More populations of the variable U.reniformis would have to be studied and compared. But judging from the pictures & drawings above, I see no proof that U.cornigera has uniquely shaped traps/antennae or that the dimorphism itself is unique.

All the best,

Fernando Rivadavia

Edited by Fernando Rivadavia
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Hi Fernando,

I can confirm that aquatic traps have antennae either pointing in or out! I'm not going to be home for another week but I will look at them when I return. This may change with age. ie new traps point bending back as they age.

I only skimmed over the paper so didn't realise that the terrestrial trap was terrestrial which is why I discounted U. cornigera as the hybrid. Upon reveiw I agree that it certainly could be of hybrid origin. I'm now looking forward to flowering!

Cheers

Greg

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Hey Greg,

Thanks for the info! So the antennae point both ways, huh? Yeah, it could definitely be an age-related thing, who knows?!

Anybody else have this hybrid and willing to take a look at the traps? Or even those of U.reniformis and U.nelumbifolia (old X new, terrestrial X aquatic)?

Thanks,

Fernando

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