Utricularia pubscens

[guqin]

Does anyone one here has any experience with growing this species from seed?

I have one successful germination, but three weeks later, the seedling still have only a pair of cotyledon leaves. Is this normal? (Potting mix 1:1 peat/sand; water tray; RO water; covered with plastic cup to maintain high humidity)

 

[Giles_KS]

Are you sure your seedling is U. pubescens - probably someone will contradict me on this, but I'm not sure that they have normal cotyledons like other plants?

Giles

 

[guqin]

Opps. I thought that all Utricularia belongs in the Subclass Dicotyledonae?

 

[Giles_KS]

Yes, they do (sort of). But that doesn't mean that all dicot species have to have two cotyledons. Utric morphology is generally wierd and it is not always easy to compare utric vegetative organs with those of other species. Does your seedling have any roots (although not that you're going to look)?

Giles

 

[guqin]

I do not really know, short of uprooting the plant!

The seedling is just sitting there with two leaf-like structures looking forlorn for over three weeks already. I know what the mature leaves look like, but the present leaf structure certainly does not conform to what I have seen as U. pubescens leaves. Should I dig around the substrate to see whether there are stolons or traps?

 

[Giles_KS]

No - I'd just leave them and see what happens. It's better to have an unidentified live plant than an identified dead one,

Giles

 

[dodecatheon]

To address the picky technical question: no utrics do not have coteledons, and no roots at any stage of development. The utric embryo looks like an green blob with a few protrusions, which can grow into "leaves", stolons, rhizoids, bladders etc. See F.E. Lloyd for some drawings of utric germination and development.

As to the horticultural question, a utric seedling will grow one leaf at a time, if, at germination, you see two leaves arranged in the typical dicot seedling pattern, you likely don't have a utric. However, slow growing seedlings are typical of the genus, and can be very frustrating. I would recommend watering daily from above with a spray bottle. I find that utric seedlings are very suscenptible to being taken over by algal slime, or moss, liverworts etc that gow on the surface of the soil.

 

[guqin]

That clears up the confusion somewhat. Thanks!

So, the seedling with the cotyledons leaves in the pot is defintely not a utric.

However, I have just noticed that there is a sliver of a transparent green hair on the surface of the potting pix. Could this be part of the utric?

 

[dodecatheon]

From what I've seen, the first sign of a germinating utric is a tiny, but still well-formed utric leaf. It is usually about .1-.2 mm in size when I notice it.