natural Drosera filiformis X tracyi hybrid

[Randy Zerr]

Makoto Honda was with me on this expedition and agreed that these appear to be a hybrid. At a small, remote section of the largest D. filiformis site I have found, Drosera tracyi grows mixed with the reds in an open area perhaps 100 ft by 200 ft . The tracyi are the typical larger all light green plants with short, colorless tentacles found all over the gulf coast . The filiformis are the smaller, unique deep red plants indigenous only to this area. Many examples of an intermediate was found mixed in with the two species and showed all the characteristic of being "half and half"
To me they appear to have an orangish glow from a distance compared to the two species.

[meadowview]

Hi Randy:

This is the first time I have ever heard of Drosera trayci growing with D. filiformis in Florida. Is this a new report and has D. trayci been missed by all the other investigators at this site? I thought the population consisted exclusively of D. filiformis.

Since you have now demonstrated D. trayci is growing with D. filiformis in Florida I am afraid that someone has made the incredible error of introducing D. trayci to this population. Alternatively, and even more ominous, is the possibility that hobbyists and naturalists have unwittingly transported D. trayci seed to this site on their shoes.

While it is possible you have discovered a natural sympatric colony of both Drosera taxa, I think it very unlikely that these two taxa would naturally co-occur due to their great ability to inter-cross and thereby break down distinctive species characteristics.

Sincerely,

Phil Sheridan
Meadowview

[Randy Zerr]

Hello Phil. I too have considered the possiblility that these D. f. var. tracyi plants are introduced by man. They are in a very remote location and the colony seems well established, covering most of the suitable habitat which is blocked on two sides by dry, unsuitable soil and terminates in other directions by occasional flooding by the pond. The higher ground has more var. tracyi and fewer filiformis while the wetter end is the opposite. The red D. filiformis does occur over suitable habitat around the entire perimeter of this pond. There is still about 25% of this extensive habitat, which covers over 2 miles of ponds and seeps, that I have not explored which I plan to complete later on. My understanding is the man made hybrid of D filiformis X tracyi is sterile. We were looking at these and could not find variants that appeared to be backcrosses. Only three distinct types could be found. The tracyi, the red filiformis and the intermediate which in all examples appeared to be "half and half"

[meadowview]

Hi Randy:

I wish we could get some more comments from the audience here on whether D. trayci has ever been seen at this site. Do you have a reference backing up the infertility of the hybrid? This is turning into a rather interesting topic.

Best,

Phil

[Randy Zerr]

I know I am not the first to find these plants. Last year when I first found and explored this site, all that I noted was the extensive population of D. filiformis reds and a pocket of Pinguicula planifolia. I'm sure others have been here and seen the same, it's a large area and on state land. I didn't explore the entire area. Later I gave the location info to another CP explorer who reported finding tracyi here and what looked like hybrids with the red filiformis. He didn't give me exact location info but assumed it had to be in an area I had not explored and it didn't take long for me to find them. Unfortunately I cannot find the emails that I exchanged with this gentleman and forgot his name so cannot contact him. Maybe he will read this.

I've not paid much attention to Drosera hybrids but read in Don Schnell's book "Carnivorous Plants of the United States and Canada" that North American Drosera hybridize easily but the resulting plants are sterile and cannot backcross.

[meadowview]

Hi Randy:

Yes, most Drosera hybrids are sterile based on empirical studies. However, sterility of hybrids between D. filiformis and D. trayci has not been assessed to my knowledge. In fact, since these two Drosera taxa appear to be closely related it seems likely the hybrid may be fertile. We'll just have to look at this and find out. In fact, would it be possible for you to get permission to obtain live samples of the fruiting putative hybrid and send to us for analysis? A germination test could quickly resolve the issue.

I look forward to seeing this site in the future with you.

Best,

Phil

[Brian Barnes]

Hey Phil and Randy,

For a point of reference, here's photos of a legitimate cross I made over a year ago between;

Drosera filiformis 'Fl. red giant' and Drosera tracyi 'white flower' (antho-free)

The resulting hybrid shows the "orangish tint" that Randy speaks of. I hope to offically name this one D. X 'Florida Fury' after more study. Unfortunately, it probably will not flower until next year, although destinctive cultivar traits are present in the leaves of the fore-mentioned hybrid.

Happy Growing,

Brian.

A pot of hybrid seedlings. Note diversity amongst propagules;




Here's the parents;

[Randy Zerr]

Nice plants Brian. You must have quite a collection with all the material I've seen from you on here.
I think the red florida D. filiformis deserves it's own name. How about something like D. filiformis var. rubrafolia?

Phil, I'll see what I can do. Seeds should be ripening in a month or so.

[Dave Evans]

Hey folks,

Don Schnell is right, all the North American species of Drosera produce non-fertile hybrids; unless a mutation happens which effectively doubles the chromosomes in the resulting hybrid.

This is why D. filiformsis and D. filiformis var. tracyi are in the same species, they can freely interbreed just like Nepenthes and Sarracenia. It has been known since the early 90's, at least, that the hybrids between all the various D. filiformis variants are fertile and can go on to produce another generation of D. filiformis--there are also no significant differences in the flower structures and/or flower behavior like what time in the morning the flowers open and what time of day they shut.

Drosera 'California Sunset' is very fertile and produces hundreds of seeds each year. Surely, someone else has grown this plant?

I'm not clear on whether the D. filiformis from Florida should be considered the same thing as the northern plants. I think most of this species habitat was destroyed at the end of the last ice-age and most is now under the Atlantic ocean. What is left are now are non-connected populations up and down the east coast from Canada down into Florida--the main population center; where they were connected together is no long habitable. These are exactly the conditions which can induce speciation via natural selection.

So are the red plants in Florida recent immigrants from up north? How did D. filiformis and D. filiformis tracyi separate only to rejoin later? Did this process take more than one ice-age?

[meadowview]

Hi Dave:

Aha, this is exactly what I was looking for: confirmation that the hybrid of D. trayci and D. filiformis is fertile. If this applies to the Florida population (and Randy can send us seed to test this hypothesis) than that really makes me wonder how D. trayci got there. If these species freely interbreed and produce fertile offspring then we should ultimately have a hybrid swarm and not discrete taxa at this site. Unless... there are some significant natural selection forces favoring maintenance of separate taxa (e.g. meaning we really have two species).

At this point, I'm leaning towards a recent immigration or introduction of D. trayci at this site to explain the phenomenon.

Sincerely,

Phil Sheridan
Meadowview

[Brian Barnes]

Hey Folks,

Yes indeed, D. x 'California Sunset' does make tons of seed. The cultivar description of the forementioned states that the seed should be destroyed. Quite naturally, for cultivation/distribution purposes, as to not taint the original cultivar traits.

I would love to see what diversity emerges from such germination. This topic is beginning to consume my interest as well. ;D Unfortunately, my hybrid will not flower until next Spring.

Happy Growing,

Brian.

[Michael Catalani]

May 14, 2009 12:17:17 GMT meadowview said:

If this applies to the Florida population (and Randy can send us seed to test this hypothesis) than that really makes me wonder how D. trayci got there. If these species freely interbreed and produce fertile offspring then we should ultimately have a hybrid swarm and not discrete taxa at this site. Unless... there are some significant natural selection forces favoring maintenance of separate taxa (e.g. meaning we really have two species)

Hi Phil,

One likely reason these two plants can co-exist without hybridizing each other out of existance is because Drosera self pollinate themselves. There is only a few hours when the flower is open for a potential cross to be made or else the flower self pollinates.

The testament to how effective this self pollination is can be seen by exploring the areas where several different Drosera species coexist within inches of each other, and where the flower times are practically the same. Drosera hybrids are not easy to find in the wild. Considering the plants produce scapes of multiple flowers that open up over weeks, and that there is plenty of times when flowers of 3 different species in a gulf coast bog are open at the same time, you would expect hybrids to be somewhat common, even if they were infertile and could not reproduce.

Now, if the red form and tracyi hybrids are fertile, then they could keep regenerating themselves from seed, which could keep their populations going. But they still could not easily backcross into one of the other forms due to the short time a flower is opne before it self-pollinates.

About a month ago I decided to look into the two different florida red forms of filiformis, and ordered seed from the ICPS seed bank and from ebay. One form was reported to be larger, and produced a hibernacula in the winter, whereas the famous red form was smaller, didnt form a hibernacula, and could be grown as a tropical plant year round. I had a sneaky suspicion that the larger red form was a cross between the red form and tracyi, and that seed collected from the wild from the larger hibernacula forming plant was from a hybrid cross.

Its been years since I visited one of the red filiformis sites. I know that the site I went to around 2000 / 2001 is now a subdivision, although the plants are supposed to still be there. At that time, I did not notice tracyi growing intermixed with the red form, but the tracyi plants where nearby. And I could have totally missed them considering how little time I had to spend there.

[Dave Evans]

May 14, 2009 17:32:10 GMT Michael Catalani said:

[
The testament to how effective this self pollination is can be seen by exploring the areas where several different Drosera species coexist within inches of each other, and where the flower times are practically the same. Drosera hybrids are not easy to find in the wild.

This probably depends on where you look... I personally have found hundreds of individual Drosera hybrids in the wild over the years. They are much rarer then the parent species, but they are around.

Considering the plants produce scapes of multiple flowers that open up over weeks, and that there is plenty of times when flowers of 3 different species in a gulf coast bog are open at the same time, you would expect hybrids to be somewhat common, even if they were infertile and could not reproduce.

I noticed that the insects visiting D. filiformis flowers cannot in turn visit flowers of the smaller species as they are too large and don't even go near the D. capillaris or D. brevifolia flowers. Basically, D. filiformis flowers are in a different habitat as far as the pollinators are concerned. A strong pollinator selection will limit the creation of hybrids to some other mechanical action like wind blown debris or some larger animal pushing the two species open flowers together. And I've never found a hybrid involving D. filiformis and another species. I know of only one site where D. hybrida was found and that location is down to one clone.

On the other hand, the flowers of D. rotundifolia and D. intermedia are much more similar in appearance; and the hybrid D. beleziana is fairly common. Probably due to both species having more overlap in pollinators that will visit both species.

When I use the word D. filiformis, I'm referring to all its variations, not just D. filiformis var. filiformis.

I would say even though D. filiformis self pollinates very well, the strong pollinator selection for D. filiformis flowers will continue to mix the two varieties. This might not be an un-natural occurance though, but rather nature doing what it does.
This mixing could lead a fourth variety in the species if it doesn't eat up the pure red plants; which from what I understand have a very small area they occur within.

[Randy Zerr]

I've finally remembered who it was that found this site last year and there may be other's nearby so plan to explore more. Also received a response from a leading botanist at FSU Tallahassee who says he himself has seen the two species growing together in this county but never a hybrid.

[reptiluvr]

I believe I have found some hybrids as well. I found some conspicous D. tracyi with reddish glands but regular green petioles. I didn't search extensively in this area for true D. filiformis but I wasn't particularly looking for them anyway. I just found a few plants that differed from most of the other D. tracyi around. I'm very amateur at botany so correct me in any misuses of words as I'm actively learning right now. Anyway here's some pics and tell me if you think this is a hybrid or just a colorful D. tracyi.


A young leaf still not fully extended


Another view of this leaf


An older leaf that was drying out


Whole plant in situ