Venus Flytrap growing

The International Carnivorous Plant Society (ICPS) maintains a list of registered cultivar names for Dionaea muscipula Soland. ex Ellis (aka Venus flytrap).

From Wikipedia: A cultivar is a cultivated plant that has been selected and given a unique name because it has desirable characteristics (decorative or useful) that distinguish it from otherwise similar plants of the same species. When propagated it retains those characteristics.

Here is a complete list of all of the current Venus flytrap (Dionaea) cultivars registered with the ICPS.This list does not include those cultivars which are not fully registered with the ICPS such as Dionaea ‘Clumping Cultivar’, Dionaea ‘ Big Mouth ‘, Dionaea ‘Kinchyaku’, Dionaea ‘Red Rosetted’, Dionaea ‘Royal Red’ etc.

Dionaea ‘Akai Ryu’ - aka Dionaea ‘Red Dragon’

The most common red form of the Venus flytrap. Is known for it’s intense dark red colouration.

Dionea ‘B52′

Currently considered to the largest Venus flytrap cultivar. Optimal growing conditions are required for these plants to reach their full size. Poor growing conditions will result in a plant the same size as any other.

Dionaea Clayton’s Red Sunset

Red with long skinny petioles (particularly during winter) whereas other red cultivars have quite wide petioles. They often lose all of their leaves during dormancy.

Dionaea ‘Cupped Trap’

The traps are joined at one end, creating a cup shape. Despite their warped appearance the traps still function correctly.

Dionaea ‘Dentate Traps’

The spines of each trap are short and triangular like a sharks tooth instead of long and skinny as in ‘regular’ varieties. The spines of small/younger plants do not shows these properties as prominently.

Dionaea ‘Fused Tooth’

The spines of the traps are bent out of shape, fused together by webbing. The traps usually look normal during spring however.¹

Dionaea ‘Green Dragon’

This is believed to be a mutation of the ‘Red Dragon’ cultivar, but the edges of the traps do not turn red, even when exposed to intense sunlight.

Dionaea ‘Holland Red’

A red variety which is often green when growing in insufficient light.

Dionaea ‘Jaws’

The traps are very big and have short, pointy spines.

Dionaea ‘Justina Davis’

The traps are always green, even when exposed to intense sunlight.

Dionaea ‘Louchapates’

The spines of the traps are split and found at the ends of the trap lobes.

Dionaea ‘Petite Dragon’

Has the same deep red colour as Dionaea ‘Akai Ryu’ but is not as large and has bifurcated flower stalks.

Dionaea ‘Red Burgundy’

A red variety which is known for having rapid growth characteristics (for a red variety).

Dionaea ‘Red Piranha’

Has short, triangular spines like Dionaea ‘Dentate Traps’ but the intense dark red colouration of Dionaea ‘Red Dragon’.

Dionaea ‘Sawtooth’

Similar to Dionaea ‘Dentate Traps’ but with trap spines which are modified into short, sawtoothed edges.

Dionaea ‘Wacky Traps’

The leaves are incompletely developed. This is an extremely slow grower that also has strangely distorted flowers. Known in some circles as “Bart Simpson”, but this name has not been established and might even violate some trademark laws.

Cultivar Groups

From Wikipedia: Under the botanical nomenclature of the International Code of Nomenclature for Cultivated Plants (ICNCP), a cultivar group is any gathering of cultivars designated by common traits.

Dionaea Dentate Traps Cultivar Group

This cultivar group contains all plants with short, triangular shaped spines.²

Photos of ‘Fused Tooth’ and ‘B52′ courtesy of Corrosive Halo. Photo of ‘Red Dragon’ courtesy of Cobalt Crow.

The mechanism by which a Venus flytrap moves is poorly understood. When the trigger hairs on the trap are stimulated, an action potential (mostly involving calcium ions) is generated, which propagates and stimulates cells. Exactly what this stimulation does is not clear. Cells in the flytrap may rapidly secrete protons into their cell walls, thereby loosening them and allowing them to swell rapidly by osmosis. Alternatively, cells in the flytrap may rapidly secrete other ions, allowing water to follow by osmosis, and the cells to collapse. Once the trap has rapidly shut, the bug will continue to stimulate the inner surface of the trap, causing a further growth response forcing the the edges of the trap to close and eventually sealing the trap ready for digestion.

Contrary to popular belief, Venus flytraps do not make acids. The digestion process is in fact caused by enzymes secreted by glands in the trap. The enzymes reduce the protein in the bug, reducing it to a skeleton. The trap then reopens, ready for reuse. Traps typically only open or close three times before dying.

More detailed information about the movement process can be found on the Venus flytrap Wikipedia page.

Photo courtesy of Jamie Duke.

So … you want to grow your fly trap into a child swallowing monster eh?

Well I hate to break it to you, but you can’t! The largest a Venus fly trap leaf can grow is about 3 cm across, that’s barely large enough to fit a mouse let alone a human! Also, that is the largest they can grow, most plants rarely get anywhere near that size. The average size of a house hold Venus fly trap leaf is about 1.5 cm across.

The best way to grow large traps is to follow the advice here on this blog. The largest plants are usually the healthiest plants, so make sure you follow all the tips on here and hopefully your plant will grow to a healthy size eventually. But alas, that child swallowing monster isn’t going to happen - except maybe in your dreams, or nightmares depending on your perspective on life.

Argh, it’s winter an my plant is dying! What do I do?

Don’t panic, that’s what! Venus fly traps normally go into dormancy for the winter months and that is probably what it happening. During dormancy the plant will stop growth and some of the leaves may dye off, this is entirely normal.

What you shouldn’t do, is take your plants out of dormancy, they really don’t like it! Some experts claim to have more luck by avoiding the dormancy period, but most growers are better off putting their plants into dormancy as not doing it places your plant at risk. The best way to deal with dormancy is watch your plant, if it is late summer and your plant is growing more slowly and less traps are being formed then it’s likely your plant is heading into dormancy. If this is the case, then you should make sure your plant is moist, but not soaking with water. If possible you should place your plant in a chilly spot during the dormancy period.

If you live in a moderate climate (above freezing temperatures) and usually keep your plant inside, a simple way to place your plant into dormancy is to move it outside for the winter. The cooler temperatures outside will place your plant into a healthy dormancy.

If you live in a colder climate (below freezing temperatures) then place your plant in a cooler part of the house. Against a window in a cooler room works good, the window will hopefully keep the plant cool enough for dormancy to occur.

A more drastic solution which may work, is to place your plant inside sealed bag and stick it in your fridge for the winter. This is somewhat risky as your plant will enter into a total dormancy which is not a natural state for them. But this technique has had a lot of success for those who have tried it.

Whatever you do, don’t put your plant somewhere out of the sun apart from in the fridge. Refrigeration places your plant into total dormancy so it does not need to photosynthesise. However if you don’t cool the temperature down to zero and/or remove all light, the plant will still attempt to photosynthesise and will likely die.

It is entirely normal for a healthy plant to have dead traps. Traps normally die because of digestion rot, although old age will kill them off too. In general, the healthier your plant is the less likely your traps are to die. But don’t worry about it too much, dead traps are natural.

Those black, hideous looking skeleton filled traps are a part of your plants eco-system, so there’s no reason other than for cosmetic purposes that you should remove them. Sometimes I clip them off with a pair of scissors to get them out of the way of knew growth, but I always leave the leaves in the pot as a bit of natural nutrients for them. You can remove them from the pot if you really want though.

Small black spots like that shown in the image above is common after digestion of prey. Photo courtesy of Canon Fodder.

The video below nicely demonstrates the motion of a Venus flytrap being triggered.

If you have read our “How do the traps move” article you will already know that the movement of a Venus flytrap is poorly understood but is likely related to the flow of ions inside the plants leaves.

However, this only explains the initial motion of the trap. The aggressive fly trapping strength is gained from far simpler means … the secret to the Venus flytraps speed and strength does not rely in muscles or flows of ions, but the geometry of the traps.

Imagine a tennis ball which has been chopped in half and inverted. The tennis ball is quite stable in it’s inverted state, however if you bend the ball even slightly back towards it’s usual state, it will snap back into place very quickly. This is similar to the process occuring in a Venus flytrap. The traps are effectively in a constant state of inversion just like the tennis ball, when the trap is triggered, the plant pushes it’s lobes inwards triggering the snap and consequent consumption of it’s tasty prey.

There is only one genus of Venus flytrap … Dionaea muscipula Soland. ex Ellis. However there are many different varieties of this one species.

Most cultivar species are distinguished by the colour of their traps, their trap shape and the size of their traps. Traps with strange shapes such as short or triangular shaped spines, deep red colours and abnormally large traps are often given their own names.

For detailed information on the taxonomy of carnivorous plants I recommend checking out Barry Rice’s carnivorous plants taxonomy page.

Photo courtesy of Thane.

Well, that could be one of many things.

The most likely answer however, is inadequate lighting. Venus fltraps require huge amounts of light and if your plant isn’t getting it then it will likely die. Full, bright sun all day long is the best solution to keep Venus flytraps healthy. With good lighting they can survive without being fed, minimal water, poor’ish soil conditions and lots of other nasty problems which afflict them. But if you keep your plant inside or live somewhere which is regularly overcast then you will likely have trouble keeping your plant healthy.

Remember that just because a few of your traps have turned black that doesn’t mean your plant is dying! Those traps will probably grow back nice and healthy in a few weeks anway.

Also, if you don’t know about winter dormancy, then go visit the winter dormancy post.

Plants generally get their nutrients from the air and nutrients in the soil. Flytraps however are native to humid boggy areas in North and South Carolina where acidic soil lacking in vital nutrients are found. The plants evolved to cope with the low nutrient soil they live in by extracting their nutrience from bugs. Venus flytraps can survive without catching bugs, but will generally grow faster with them.

And anyhows, imagine living your life and never getting to eat anything but dirt. A few bugs would probably start to sound appetising after living a life of sucking your nutrients out of the garden!

Photo courtesy of Jamie Duke.

If you find that your plant has grown two traps on one leaf, don’t get too excited. Your plant is not special, it has just formed a simple trap twin. This is not common, but is nothing special. The reasons for the formation of these twin traps is not entirely clear and there have been no reliable reports of anyone being able to grow plants which do this any more than others. These freakish twinned traps are certainly interesting to look at though.

Some people have also reported the formation of triple traps, however this is extremely rare.

Images used on this page courtesy of Lucas.