Tuberous organs in Utricularia

[Dave Evans]

Dear Barry and Forum,

I am confounded by Taylor's description of many Utricularia as annuals. I have yet to find such plants. All the _Utricularia_ I've grow and studied are perennials. Why does Taylor describe _U. radiata_ as an annual? It has an annual growth cycle, just like the rest of the perennials it lives near...

Was he simply too used to thinking about Utricularia as tropical and so members act as annuals in temperate climates? I don't really follow the logic here...

[agamemnon]

Dear Mr. Evans,

please, I would like to start remarked that the professor Peter Taylor worked on the basis of information and observations in the natural biotopes. Such conditions can not be completely imitate in the culture. Many species are dependent on the conditions of the "laws of nature". For example species Utricularia dunlopii grow in areas that are flooded at certain times - in this time the plants germinate, grow, make flower and produce seeds). Further, in the the dry season U. dunlopii die because can not survive in the dry soil. - That why prof. Taylor write annual species.
In domestic terms this plant (species) grows as a perennial because I can provides a permanent good growth conditions (temperature, water, artificial light etc.).

Maany information will be introduced in the new international project about the genus Utricularia - Atlas of the bladderworts that we are prepare published very soon. Next information I will send in to this forum as we will get final list of Volume I (together will be four Volumes).

[Dave Evans]

Well, I agree some species do appear to be annuals, but I don't think a plant that survives over winter as a dormant structure, even if it is just a small bit, should be considered an annual.

Only species which only survive as seed, like _U. dunlopii_, should be considered as such.

I'd be very interested to know, if anyone knows when the seeds of some of these "annuals" germinate? One day, there are no Utrics, then in a couple days, lots. Where do they come from, it cannot all be seed...? They mostly appear to rise up from the bottoms of the streams or ponds. I suppose the seed might germinate and grow for a while at the bottom (where there no light--wait that doesn't make sense)...

Anyway, I don't recall all the species I have this issue with. But U. radiata is one of them; I belive U. flaccida is another. I'd really like to verify U. radiata is an annual.

[meadowview]

Hi Dave:

Utricularia radiata is a problematic species as to its true nature of habit. I posted a question last year on the list serve about this species and got several answers, similar to what our European friend mentioned. To whit, the species is generally an annual but can be perennial. We are cultivating U . radiata and I'm similarly confounded by its behavior. We had a number of plants for a a year or two and then the population collapsed and some new individuals appeared in tanks away from the main colony, go figure. Perhaps U. radiata at best is a biannual. Utricularia radiata does not seem to share the perennial habit of most of our North American temperate aquatic bladderworts which makes it somewhat unique.

Dave, look forward to your next visit where we can explore the nuances of this interesting plant.

Sincerely,

Phil Sheridan, Ph.D.
Director
Meadowview Biological
Research Station