Most drosera can be most easily be propagated by leaf cuttings.
Years ago I read that, potentially, each tentacle on the leaf
is a potential new plant, although you never get that many. I
don't know if this assertion (now 13 years old) is correct, but
I do know that you can do leaf propagation.
The procedure: snip off a leaf near the base. You want as much
leaf as possible, as small chunks of leaf stand a greater chance
of rotting before a leaf bud 'takes'. Long leaves such as
D. filiformis can be cut into 2" long chunks. For budding it
is preferable to have some live spahgnum moss, but even peat
can be used to bud. lay the leaf down on the surface of the media
so as much as the surface of the leaf is contacting the soil.
Make sure the leaf is tentacle side up. Ideally you'll have
at least enough live spaghnum to spread lighty over the top of
the leaf so it will keep the leaf damp (but not wet), but putting
the whole thing in a high humidity environment (i.e. a ziplock
bag or terrarium) should work. That's it. As long as humidity
is up and the soil is damp (not too soggy), you should have new
plantlets in a few weeks. Wait a few months so the plantlets
can develop roots. The smaller the leaf blade, the more difficult
it is to use this method. A few plants, such as D. schizandra,
D. adelae, and D. prolifera, are slower to produce leaf bud
plantlets. Oh yes, try and pick a young leaf, not an old and
dying one, for this procedure.
Leaf budding produces mature plants faster than seed, but not
in as profuse quantities. Use this method to propagate plants
for sale, trade, or gifts.
Robert