Just bringing this post back up...
Hi Ron,
I think you have a point there with the low humidity. Some of my healthiest petiolaris Drosera plants are grown under low humidity. I've been growing Drosera paradoxa from seed to flowering plants within 6 months in an outdoor terrarium that is 75% covered(traps the heat but not much of the humidity). It seems like the perfect place for cactus, rather than Drosera.
Otherwise, I have an indoor setup consisting of a large plastic container covered partly with some saran wrap(again to trap heat rather than humidity). The container sits on a heat mat(used on winter nights, but not in the summer) and the plants do not sit permanently in water as I allow the tray to dry out for a couple days between watering. When I use bottom heat, I take off most of the covering. There is no condensation in the container, even at night. Plants are grown within inches of 4 40watt flourescent tubes-cool white.
Here is a hairy form of D.paradoxa from 100km north of Drysdale River Station grown outdoors year-round. This plant will go into a semi-dormant state during the winter(smalller leaves), but still grows.
Drosera kenneallyi "type form"-Theda Station, Kimberley, WA
This particular clone produces traps that are naturally folded, even without prey, however, I did recently feed the plant in the photo. I have another clone from the same location growing in the same terrarium that produces the normal nonfolded traps. This was grown indoors in the above mentioned setup:
Drosera aff.ordensis "narrow leaf form"-Theda Station, Kimberley. This was indoor grown in the above mentioned setup:
Trap detail, recently fed:
Drosera lanata "type"- Lotus Glen, Mareeba, N.Queensland. Grown indoors in the above mentioned setup:
Drosera paradoxa "pink flower"-Mt.Bomford, Kimberley, WA. These were grown under ~80% humidity in a tray with the 2in humidity dome separate from my other petiolaris dews. Somehow a moth got inside...
I've also noticed that the traps of Drosera petiolaris move faster than most other Drosera species(besides maybe burmannii etc.), especially on a hot afternoon.