Utricularia reproduction

[Tamlin Dawnstar]

On a whim, I took a moss congested pot of D. dichotoma, plunked the mass out of the pot, and set in in the water of my bog about 2 weeks ago. When I checked it today, I am astounded at the growth it has put out. It is reproducing at least 3 times as rapidly as in a terresterial medium, and the growth is thick! At the current rate it will double its biomass in a month, possibly due to increased available prey.

I am about to try the same thing with U. pubescens, and will continue with other species if I have the success I expect. Preliminary data suggests that these plants do not like pots!

 

[dodecatheon]

I've tried U. uliginosa, flaccida and dichotoma submerged and they grow really well and with quite different leave forms. I also found however, that you can only have them growing like that for about 6 months or so, then they start to decline.

 

[Guest]

By preference, I would grow U. dichotoma under several inches of water, where it grows as thick as grass and throws up loads of flowers. I don't think this species is a terrestrial, but a marginal aquatic. However, for current convenienceI have it growing in Sphagnum, terrestrially. I also think plants are less prone to rot under water as opposed to being wet, especially over winter for eg. D. intermedia. I would be surprised if U. pubescens was happy under water, but go ahead and surprise me.

What do your plants decline from, Dodec? Is it that they run out of space quickly, or something more fundamental about being kept permanently submerged. If so, it could be connected with a habitat of fluctuating water levels.

Giles

 

[Barry-Rice]

Hey Tamlin,

It *is* interesting when these terrestrial species start growing like aquatics. Utricularia uliginosa, U. calycifida, and U. longifolia come to mind as plants that do this. Sometimes the leaves are two or three times as large when they grow as aquatics, and the leaves just lay on the water's surface. Weird. Unfortunately, these aquatic leaves are very sensitive to abuse, so beware of using aquatic growth as trading material---they don't always survive shipping well, and are prone to damage if transferred to the usual terrestrial growing conditions.

Cheers

Barry

 

[dodecatheon]

U. flaccida is especially interesting when grown submerged as it develops the pinnately-shaped leaves shown in Taylor. I don't find that it grows these leaves when grown as a terrestrial.

Giles: I don't know what the cause of the decline is. Rot perhaps? A fluctuating water level would probably help.

I expect that a lot of utrics experience seasonal flooding in habitat - a habitat that is uniformly wet, but still above the water level would be hard to come by. I think you might be a bit hasty in classifying it as a marginal aquatic - judging by the observations in Lowrie's Vol.3, it is quite opportunistic and will grow anywhere where that there is a wet acidic substrate.

Of course, I only grow plants aquatically if I have to - I don't have the space to grow all my utrics in containers large enough to raise the water level above the soil level. They also tend to get a bit slimey, and the stray bits of floating plant make me afraid that pots will get cross-contaminated.