- Pit Traps - the California Snake Lily, Darlingtonia
- Glue Traps - the Butterworts
- Tentacle-y Grab Traps - the Sundews
- Suck-things-in Traps - the Bladderworts
- Snare Traps - the Oyster Mushrooms
The only major commonly accepted group missing is the Snap Trap group, which only contains a single species in the entire world, the Venus Fly Trap of the Eastern U.S.A.
While growing these is generally not a simple affair (not great choices for the beginner), they can be cultivated. If you are going to grow these, always start with a reputable nursery - locally I can recommend Predatory Plants along highway 92 on the way to Half Moon Bay (we have no ties to them, we just find them reputable and friendly).
Last August we went to the mountains of far Northern California - the Siskiyous. This is a great place to see some carnivores in the wild, including our biggest, the four-foot-tall Snake Lilies, Darlingtonia californica:
Our son says "I'm looking at Snake Lilies and they look like long snake-like lilies and the lilies are long like a snake. Snakes are long like these stems. They eat bugs and flies. Thank you, that is my blog post".
These are challenging to grow, as they grow with their roots in cold underground streams (scree slope seepage). We bought one from the nursery in Half Moon Bay, and it is doing well courtesy of some engineering, at least so far. The heat of Summer will be challenging.
These plants have tall, hollow leaves with slightly open "lids". Water laced with digestive enzymes fills the upright hollow stems, with a fragrance of water and rotting things (yummy for some bugs at least). The inside of the trap is lined with down-pointing fine hairs. When bugs try to climb out, even if they make it up the stem, the lid has false "windows" that the bugs make towards, only to find their way blocked. This is a lot like the way a yellowjacket trap works, except when the bugs become exhausted they fall not to the ground, but into the pitcher's digestive liquid.
Another type of carnivore deploys "Fly Paper", in this case the entire leaf coated with sticky stuff. These are the Butterworts. Below is Pinguicula macroceras from Del Norte county:
Bugs get caught on the sticky leaves and are digested in place - the plant senses the bug and exudes digestive enzymes that dissolve the parts of the insect containing useful nutrients, leaving behind the empty shells of indigestible chitin. The lower photo shows a large number of small flies caught on the leaves, in various states of digestion.
Why eat bugs at all? Bugs, and animals in general, are full of several nutrients that plants need. These plants are scavenging typically nitrogen or phosphorus from the insects, either or both of which can be in very short supply in certain environments, such as mineral spring seeps.