# Is there a descriptional plant key?



## Andi (Feb 6, 2008)

Because aquatic plants can vary greatly depending on the environmental conditions I'm having a difficult time identifying plants using picture keys.

Does anyone know of a descriptional plant key? I understand that a lot of the new variants in the hobby probably wouldn't be included, but a key could get me closer.


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## Cavan Allen (Jul 22, 2004)

Do you mean one based on characters in sterile (no flowers or fruit) submerged plants? If so, I don't think so, no. I think it would be pretty tough for the reasons you mentioned, but perhaps it could get one closer to the correct ID.


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## asukawashere (Mar 11, 2009)

On the other hand, we do have a wonderful ID board on this forum, so if you snap some pics and post them there you should get some useful input from members that have seen the plants under differing environments...


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## Andi (Feb 6, 2008)

I have an aquatic plant key, but it covers just the most common of aquatic plants found in the United States. I was hoping there might be something out there that was more for the aquarium hobby, seeing there are so many that are from outside the US.

For example, the book starts out discerning between plants with true leaves, stems and roots and those without. Depending on the answer the key leads to different sections of the key. One of the first plants divided out is the liverworts, followed by the duckweeds.

Another example is at the point Elodea is keyed out it says:
"Leaves narrowly ovoid, or elliptic (in one species nearly linear), 3 (rarely more) at each node (rarely 2 opposite leaves); plants dioecious; pistillate flowers floating at the surface on thread-like stalks, petals 3, white or pink (Waterweed)."

It then goes on to show drawings of a bunch of different species and there names with some information about the genus, such as in this case, that "all species are popular as aquarium plants".

It would just be very helpful to have a guide/key that could be used to distinguish between plants. I mean, what is it that the people that have to get identifications positive do? A key such as this works on the physical characteristics of the plant, not what it looks like. Granted, pictures are helpful, but can be handicapping as well.

Aquamoss does a nice job at identifying between mosses. That's an example where they have used pictures to help and does it well. This is a link for java moss.
http://www.aquamoss.net/Java-Moss/Java-Moss.htm


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## asukawashere (Mar 11, 2009)

The thing is, most of the people who have to ID plants for professional reasons have at least a vague idea of what part of the world their specimens came from, and/or the family to which they belong. Most of the keys and monographs are organized around those categorizations, which have solid scientific bases, rather than whether you typically see it in any particular trade—which makes sense, because markets vary over time, and something that was common years ago may be difficult to find today or vice versa. Whether a plant is native to any given landmass doesn't change, and how distantly related it is to any other given plant is constant (though things do get shifted to reflect out growing understanding).

There's also the fact that what we view as "aquarium plants" here are often either weeds in other countries or almost never seen in markets there. If we were to base keys on commercial availability, we'd need a different key for every country.

So, while you'll see a lot of those descriptive keys called things like "Flora of Someplace" or "Systematics of Genus/Family" you won't find something that keys out aquarium plants based on the idea that someone has them in a tank somewhere. Because laypersons would rather look at pictures rather than wade through piles of words and traditional keys with occasional line drawings, and because there's no natural, scientifically-oriented basis for calling something an "aquarium plant," there's no reason for such a book to exist—it has no real audience.


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## Andi (Feb 6, 2008)

Then what is there preventing incorrect labeling of plants if we don't have something out there to get a correct id from?


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## asukawashere (Mar 11, 2009)

...Well, the aquarium industry is rather known for ID blunders and totally made-up names. I easily could point out several wildly inaccurate trade names that put plants in the wrong order, much less family or genus (_Alternanthera reineckii_ traded as "red Hygrophila" or _Rotala indica_ cited as both "Bacopa sp. 'Red'" and "Ammannia sp. 'Bonsai'" just to name two).

That said, the places that collect plants and assign them reliable ID's usually hand field pressings and/or live specimens over to scientists, who examine the plant and key it out much as you've mentioned using treatises that are organized by continent/region or family/genus. Examination of inflorescences can lead to a good idea of what family something belongs to, then it can be keyed from there. Wild-collected plants are carefully bagged and tagged, so their place of origin is known and can be compared against historical distribution records for indications of which species it's likely to belong to, then refined in a similar manner. DNA studies, even, can be utilized by particularly determined scientists if there's an existing study on genetics within a species/genus.

Ultimately, every now and then something comes into the hobby from an imported nursery that either doesn't know or can't properly translate its origins. Those plants may go years labeled as Genus sp. "descriptor" until some hobbyist or other gets an inflorescence and presses it and mails it to the right scientist specializing in so-and-so-family. Cavan knows lots of people for that sort of thing. Note that some plants in the hobby-for instance, Poaceae sp. 'Purple Bamboo'-haven't even got a hint as to the genus (we can look at its physical structure and see easily that it's a grass, but without an inflorescence no one can elaborate on that description). The mysterious "Type 2" (formerly and inaccurately thought to be from Eriocaulaceae) doesn't even have a _family_ firmly assigned to it. There's some speculation right now that it belongs in Hydrocharitaceae, but no one's managed to confirm anything.


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## Andi (Feb 6, 2008)

There are probably dozens of people every week asking for IDs on plants. You agree there is rampant mislabeling. Sounds like there would be an audience to me. I, for one, would be an audience, and am. Its so easy for incorrect information to be passed around the internet. All it takes is 1 person that thinks they know a correct id on a reputable forum to document it wrong.

I agree that the majority of people don't care what the Latin name is and just want a ball park name of something to call it. It might not make a big difference if someone calls me by the wrong name, but if everyone starts referring to me by the wrong name it could cause issues later. Just saying. There's a reason why there is an effort to name and classify plants.

I would just like to know what it is that I have so if I post pics of it or share that I can correctly have the plants identified. I know you don't think there's a need. I just want to know if a key exists that a layperson can access.


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## Cavan Allen (Jul 22, 2004)

No, as far as I know, there is no key.

The main problem would be that you'd have to rely on characters of sterile, submerged plants, many of which are very plastic in their growth habits. I believe this comes somewhat close to what you seek, but note how many of the fields from which to chose are based on things like fruit, flowers, inflorescences and location, all things that are often missing in aquarium plants. 
http://keys.lucidcentral.org/key-server/player.jsp?keyId=43

You're right that there really isn't anything preventing bad names from being applied. But it would be far better for anyone introducing a new plant to send a fertile sample off to someone who can make a proper ID. For plants already being grown, some good photos or specimens when necessary usually do the job.


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## asukawashere (Mar 11, 2009)

It sounds smarter when Cavan says it, but that's the idea. If you're going to properly ID a plant, use the appropriate key with flowers—which is the same kind of key proper scientists use, and organized by the standards I previously mentioned. If you want a "hobby" ID, use a pictoral guide. There's no middle ground.


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## BruceF (Aug 5, 2011)

This book has some keys. 
http://www.amazon.com/Aquarium-Plan...895766&sr=8-11&keywords=aquarium+plants+books


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## Cavan Allen (Jul 22, 2004)

BruceF said:


> This book has some keys.
> http://www.amazon.com/Aquarium-Plan...895766&sr=8-11&keywords=aquarium+plants+books


Based on what characters? I'll point out that it's a rather old book too, and much has come in to the hobby since then.


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