The petiolaris-complex includes the following species, and their hybrids:
All of the petiolaris-complex sundews are found in the subgenus Drosera Subg. Lasiocephala.
To grow the petiolaris-complex drosera, not much is needed. You must follow three ground rules.
+ Avoiding Dormancy by hot conditions
+ Keeping the soil wet
+ Keeping the air humid.
So long as these three conditions are met, your petiolaris-complex drosera will survive.
Soil, Water, and Air
A mix of 1/3 Chopped LFS: 1/3 Peat : 1/3 Perlite by volume suits these plants well. They also do well in a standard 2 inch nursery pot, sitting in a Cm (1/2 inch) of water.
To keep humidity high, one should grow these under humidity domes, plastic bags, or in a fishtank. These drosera do especially well in fishtanks since they love heat. Using CFL bulbs is actually advantageous due to the heat they put off. RH should be kept at 80+%, and temperatures should never drop below 65*F (18.3c).
Watering should be done with distilled or rainwater. Tap water is acceptable for short periods of time, provided you have water with less than 50ppm of minerals in it. The San Francisco bay area, Canada, and Northern Europe all have water sources good enough to treat carnivorous plants to.
Propagation and Pollination
Flowers of the petiolaris-complex are not self fertile. They must be crossed with another plant to obtain fertile seed. All species in the complex can hybridize, and all hybrids are fertile. As such, it is difficult to obtain pure-bred seeds.
To germinate seeds, place them on chopped sphagnum and increase the temperatures. They will germinate within 2 months.
Petiolaris Sundews can be propagated through division and leaf-pullings. They will divide once they mature. To remove a division, simply unpot the plant and separate the plantlets from each other. Pot it back up and place it into its enclosure. Divisions can also be stimulated in some species (D. Paradoxa and D. Petiolaris) by slicing through the plant with a razor. Cut the plant into four pieces, and you should get four plants.
Leaf pullings work on the non-hairy species, such as D. Falconerii, Paradoxa, Petiolaris, Darwinensis, and Kennelayani. Remove leaves off an unpotted plant, being sure to get a chunk of the white rhizome. Place them on sopping wet sphagnum, in warm sun, to allow them to sprout.
If not well versed with sundews, your first petiolaris-complex sundew should be Drosera Paradoxa, Broomensis, or Petiolaris. These tend to tolerate wider temperature ranges. In hot, humid climates, like Florida, trying one's hand on any of the woolly species is not likely to be a big challenge.
Hope you enjoy this guide.