a species of one plant

this is going to be a very frustrating question, i suspect…
i have a vague memory of reading months ago about some sort of weird species of plant which reproduced by growing clones with its roots, and that the way they were all grown and ‘birthed’ meant that actually the entire species consisted of one single linked organism.
i THINK i found out about this in a straight dope article on the biggest mushroom ever, or the oldest tree ever, or some other guinness type query. i just tried searching the archives and came up empty. i might just be entirely wrong about finding this in the dope originally, in which case i’m at a total loss.
does anyone have any idea what i’m babbling about?



I read about it here, too.

There are longer articles if you google, but this is a starting point.

I suspect you may be thinking of clones of Quaking Aspen, which some have claimed to be the world’s largest single organism.

Many plants grow in this clonal fashion, spreading by suckers off the parent plant. Aspen just happens to be one of the larger ones.

But the OP is asking about an entire species consisting of only one. I’ve heard of the large aspen grove in Utah, but would that be genetically identical to aspens elsewhere on the planet?

He’s definitely talking about King’s Holly (see link). It has a triple chromosome, which makes it sterile–it only reproduces by cloning. Idnetical fossils of over 40K years have been found, and as the mutation is highly unlikely, the assumption is tha the same plant has been cloning itself all these milllenia.

it was the king’s holly i was thinking of, so manda gets the prize. those aspens are cool too though, so thanks for linking them as well.

i wonder what happened to the sexually reproducing (or at least capable of doing so once in awhile, like the aspens) king’s hollys that the original cloner presumably evolved from. how would strictly cloning to reproduce make it fitter to its environment? or was it originally a cloning species that never got around to evolving anything else? are there any animals that reproduce strictly by cloning?

The clonal species probably originated from one or both of the other diploid species in the genus from Tasmania, L. tinctoria and L. polymorpha, through some kind of genetic mix-up during pollination and fertilization. This sometimes happens in plants: instead of one (haploid) set of chromosomes from each parent, producing an offspring with two sets, an offspring can receive one (haploid) set from one parent, plus two sets from the other (diploid), thus resulting in an individual with three sets (triploid). Such individuals are usually sterile in terms of sexual reproduction since they are unable to produce pollen/ovules with a normal chromosome number. However, if they can reproduce clonally they can persist indefinitely.

It doesn’t. While clones may persist for a time, they are unable to adapt to a changing environment nearly as fast as sexually reproducing organisms, putting them at a disadvantage. Most multicellular species that reproduce strictly by cloning are thought to be rather young. However, many species, like aspens, can reproduce both sexually and by cloning.

The ancestral species apparently were able to reproduce both sexually and by cloning.

There are quite a few species of lizards and amphibians that consist only of females and reproduce parthenogenetically, in other words , by cloning. Like these plants, many are tripliod crosses between two closely related parental species. These species mostly appear to be relatively young, suggesting that these clones don’t persist very long (order of tens of thousands of years, perhaps).

As for the second part of the query - “mushrooms” - there was a number of posts recently to a thread about the Humongous Fungus. Not sure that it fulfills the “entire species as single organism” part of the OP, but it is very large, reproduces by cloning, and extremely interesting.