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Post by lizasaur on Feb 4, 2013 8:20:02 GMT
Hi Everyone! As you may or may not have seen, I'm working on a college presentation. And for it, I want to be able to cite how many genera (and which those would be) and species within each genera. I know there seems to be some difficulties, what with taxa being rewritten and new species being discovered, but I was wondering if anyone has a current count? I'm afraid I don't even know which genera are truly "carnivorous", here it seems Roridula makes the cut, but Brocchinia doesn't, whereas on Wikipedia, it's the other way around So I'm hoping there is a resident expert that can set the record straight, I don't want to quote the wrong information ^^" Bob Z. was nice enough to share this with me, so I have this as a good starting point Darlingtonia (1 species) Heliamphora (7 species) Sarracenia (8 species) Nepenthes (91 species) Aldrovanda (1 species) Dionaea (1 species) Drosera (152 species) Drosophyllum (1 species) Byblis (5 species) Cephalotus (1 species) Genlisea (20 species) Pinguicula (79 species) Utricularia (221 species) According to Wiki, there are now 23 species of Heliamphora, about 140 species of Nepenthes, 194+ Drosera, 215-233 Utrics depending on classification, and ~27 species of Genlisea... this is all correct, right? Would I go with 215 Utrics since there's only 8 Sarracenia species (as opposed to counting Rosea and other certain subspecies)? @_@ Are any of these new ones in the US? I also have currently written: "“Carnivorous” is a slight misnomer, 9 out of 10 times, the prey are insects, arthropods, other small invertebrates, and in some cases, droppings from small mammals. However, there are rare instances where these small mammals, in addition to small reptiles, amphibians, and birds become unintentional victims." Am I wrong in saying that? Is there a better way to phrase that, or a real stat (ie, 7 out of 10 times)? I want to be as accurate as possible, however, I also don't want the class to leave thinking there's any chance that they can feed whatever they find in Lowes or Home Depot ground beef @_@
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Post by Dave Evans on Feb 4, 2013 16:48:11 GMT
Roridula is not a carnivorous plant. It has carnivorous symbiotes that it hosts.
If Roridula can be consider a carnivorous plant, via a looser definition, then there is no reason not to include Brocchinia as well.
I would not say "carnivorous" is a misnomer, most animal species are arthropod ! These plants target arthropod prey for the most part, since arthropods have been around and interacting with plants for the longest time frame.
I would not call them insectivorous, they target "arthropods" which includes insects. Other associations are more species specific. For example one kind of bat is associated with Nepenthes baramensis.
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Post by lizasaur on Feb 4, 2013 17:27:30 GMT
Oh, wonderful explanation! Thank you for this!
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Post by marcel on Feb 4, 2013 17:54:06 GMT
I consider Roridula a carnivorous plant. Like many other people I use the definition of a carnivorous plant that it has to purposely attract animals and profit from them. By that definition capturing prey and let the bugs that move on you process them so you can grow is carnivorous and also a nepenthes species that attracts a bush rodent to collect its droppings. If you use a to narrow a definition you have to exclude members of families. For instance the nepenthes I just mentioned but also family members that don't produce enzymes but use bacteria etc to digest prey.
Bottom line is: there are more than one perfectly sound definition of a CP and its up to what "school" you belong to which of them you use.
The statement that about 90% are insects etc is statistically about right.
The number of species per family is also open to debate. Lumpers and splitters fighting over what is a separate species/sub species is as old as organized biology. When giving lectures I always say about so many and than move briefly into explaining why giving an accurate count is difficult with examples like showing an upper and a lower pitcher of a nepenthes species and stating that if you imagine that the pitchers grow 10 meters in a bundle of roots, twigs and liana you can easily see why people would call it two species. Next example is usually something like two similar looking sundews that grow half the world apart, then I say something like Stewart McPherson and friends that climbed a mountain were no researchers have ever gone before because the whole mountain is a prison so the first trip there resulted in new species and I concluded that in many cases actual DNA research is needed to make a conclusive argument.
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Post by ICPS-bob on Feb 5, 2013 0:33:12 GMT
I concur with Marcel. It is easier (and more professionally profitable) to name a new species (or split one into numerous subspecies) than to demonstrate that two existing species (or subspecies) names are synonyms. Now that we have new methods of genetic analysis, we will likely see some species combined and others split. There are careers awaiting in taxonomy.
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Post by Dave Evans on Feb 5, 2013 2:24:15 GMT
INext example is usually something like two similar looking sundews that grow half the world apart, then I say something like Stewart McPherson and friends that climbed a mountain were no researchers have ever gone before because the whole mountain is a prison so the first trip there resulted in new species and I concluded that in many cases actual DNA research is needed to make a conclusive argument. Not really, McPherson didn't write the species, he just re-found it. No reason to think it isn't a species, other than a healthy scientific appetite for knowledge. But seriously, there isn't any reason to think N. deaniana nor D. ultramafica are really subspecies of something else... Nepenthes, like Heliamphora and Pinguicula are very good at forming locally endemic species.
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Post by Aidan on Feb 5, 2013 11:33:38 GMT
The number of species per family is also open to debate. Lumpers and splitters fighting over what is a separate species/sub species is as old as organized biology. As is being proven in this thread... ;D
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Post by lizasaur on Feb 5, 2013 21:25:22 GMT
Hm... so I see! Thanks for the advice guys! ^-^
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Post by Dave Evans on Feb 6, 2013 2:04:29 GMT
The number of species per family is also open to debate. Lumpers and splitters fighting over what is a separate species/sub species is as old as organized biology. As is being proven in this thread... ;D Well, if Marcel was better with Nepenthes in general, yes. But all his points are "academic" in nature, not specific to the situations he is mentioning. And the issues he lists were addressed in the very publications. For example, McPherson spends some time discussing what are obviously closely related taxa and the merits of naming each one as a species. Also, there isn't any species of Nepenthes known which do not produce digestive enzymes, so why mention it like this is something well known? What is actually "missing" from that species of Nepenthes are nectaries for attracting flying insects. But the plant still has plenty of nectaries, just fewer of them on the upper pitchers that function as bat roosts... Very rarely do "lumpers" ever get anywhere with Carnivorous Plants. This is our history. Except for widespread and well know species that got named over and over, most carnivorous plants are local endemics. Local to specific geological formations. The general history of "lumpering" in carnivorous plants is one of failure to understand ecology. Example: Danser combined N. eustachya into N. alata, even though though it is physically impossible for them to be directly related thanks to the distances involved and he even mentioned how odd that the species doesn't occur on islands in between Sumatra and Philippines. To me, if you're a "lumper" or a "splitter" you're not really a taxonomist, as you're not following the data; instead you're a politician.
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Post by Dave Evans on Feb 6, 2013 3:29:35 GMT
I'll place the current number after the parenthesis.
Darlingtonia (1 species) 1 Heliamphora (7 species) 25 Sarracenia (8 species) Nepenthes (91 species) 125 Aldrovanda (1 species) 1 Dionaea (1 species) 1 Drosera (152 species) Many more species are being named. Drosophyllum (1 species) 1 Byblis (5 species) Don't know anything about byblis Cephalotus (1 species) 1 Genlisea (20 species) 29 Pinguicula (79 species) Not sure, but you can add three that were just published. Utricularia (221 species) Not sure. Probably a couple dozen more species lurking out there somewhere.
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Post by lizasaur on Feb 7, 2013 2:34:49 GMT
This is all very good to know! I found some articles about the bats! I was quite confused at first as some were published with it as N. rafflesiana and I was like @_@ I really wish everyone could just agree... it makes every level of research difficult and as a hobbyist, it's confusing too. If it weren't for this, N. baramensis would be sitting on my want list right next to N. rafflesiana var. elongata and I'd be none the wiser. @_@ Here's to the future!
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Post by ICPS-bob on Feb 7, 2013 6:08:24 GMT
Science is about disagreement, dissatisfaction with established knowledge, and working to find flaws in hypotheses and theory. For those that desire agreement, join a religion.
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Post by lizasaur on Feb 7, 2013 14:38:34 GMT
Oh, I know ^^" I just mean.... it'll be nice to know for sure what's related and what's not I appreciate the developing theories and arguments, it's most interesting, but it is also exciting to see what will come with the developments of genetic testing; settling old mysteries and giving way to new ones with new discoveries!
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Post by Dave Evans on Feb 7, 2013 22:58:29 GMT
Well for the most part, species which have been mistaken for each other in the past are usually also the species that are closely related. It is only as we become more familiar with them can we notice all the pertinent information. Previous to 2013, all plants of N. baramensis were listed under the name N. rafflesiana. I'm pretty sure this example is of two different taxa that are part of the same species, i.e. subspecies. Having grown a plant of N. rafflesiana var. elongata, I can't say it really is a different species... Or perhaps the plant I had was a hybrid between the two? As far as Brocchinia vs. Roridula being carnivorous... Roridula attracts prey which are killed and eaten by Pameridea bugs, the insects digest the food and the plant has special glands to absorb what the bugs excrete. In no way does this describe a carnivorous plant. Using the fact the plant "nutritionally benefits" from the death of the insects it traps is ignoring the fact the Pameridea are the killers, eaters and digesters, there is not much logic in saying they are ecological analogs of digestive bacteria. Roridula is more special than a carnivorous plant and belongs in a different class and is a little more unique than Carnivorous Plants. It is true, some true carnivorous plants also have similar associations, but they don't seem to be as mutual nor obligate. The feed back loop here is one where the plant air-filter captures insects and it hosts Pameridea which turned proto- Roridula into a buffet for themselves; it is such a nice place they never even leave anymore. bogleech.com/bio-plants.htmlfernkloof.com/species.mv?166www.drosophyllum.com/english/e-roridula.htmClearly, as least to me, it is the Pameridea that are the carnivores in this relationship! They do nearly all the work, right? If this plant wasn't such a perfect habitat for them, they would have gone somewhere else to kill and eat what they found in those places. Brocchinia reducta is kind of plant that probably doesn't have the right structure to be able to develop digestive glands on their leaves, and this didn't stop it from becoming a carnivore. But I think it is an accidental carnivore. It was just trying to capture dust and debris; like most bromiliads; but then it developed attractive foliage and scent to encourage insects to visit more and more often. A feedback loop of insects feeding themselves to proto- B. reducta turned it into a pitcher plant complete with flaky wax on the insides of the pitcher walls. It uses bacteria for digestion, and while digestive enzymes are usually a positive for carnivorous plant species, the lack of enzymes should not be used to rule out possible carnivory. For one thing, everything that digests foods uses and to some extent controls bacterial populations to get the nutrients. B. reducta is going out of its way to make sure the debris in its rosettes contains a lot of insects, unlike many other similar and related species. From my perspective, B. reducta is more inherently carnivorous than Roridula or Catopis. It actually eats bugs, just like Heliamphora.
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Post by lizasaur on Feb 8, 2013 2:12:17 GMT
I am so glad you cleared this up, it's like you have ESP! ^-^ Preparing the list for my thing, I was going to have a slide with ALL of the genera, not just the ones I'm covering, and examples of the proto ones, but it was super confusing, with all three of those being on both carnivorous and proto carnivorous lists @_@ But then here you are with the answer already, so awesome ^-^
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