At the start of the year I inherited a bunch of carnivorous plants from a good friend. Venus Fly Traps, Nepenthes and some Sarracenia with Drosera growing amongst them. I’ve not grown carnivorous plants before, maybe a Venus Fly Trap killed as a kid, but that’s about it. So this is a whole new world for me. Naturally I have spent copious amounts of time on google reading up on all things carnivore so I can avoid killing them and instead help them thrive. In the process of reading and getting sidetracked I discovered that Drosera are a very popular plant amongst carnivore growers and there are loads more of them than I thought. I always associated them as being one of our carnivorous plants found in the bush…
One of my ‘favourite’ plants…
Drosera are one of my favourite plants to find when I am out and about wandering. They never get old, no matter how many times I see them poking their heads up in grasslands or through cushion plants in peaty alpine areas. Up until a few years ago I had no idea we even had carnivorous plants in Tasmania. My first introduction was to Drosera peltata along the walk to Waterfall Bay down at the Tasman Peninsula. I was on a uni field trip and I vividly remember Rob pointing it out. Completely not what I would expect when thinking about carnivorous plants. It was growing in sandy, crappy looking soils along the side of track, and was tiny. Very easy to walk past and not even notice. Since them I have always had a keen interest in finding them. Not as obsessive as the fungi or the orchids, but I’ve always got an eye out for them.
The Genus Drosera
Drosera spp belong in the family Droseraceae. The family is further separated into three genera, Drosera (Sundews), Dionaea (Venus Fly Traps) and Aldrovanda (Waterwheel). Both Dionaea and Aldrovanda are monotypic, in other words, there is only one species in the genus, Dionaea muscipula and Aldrovanda vesiculosa. Not the case for Drosera though who has around about 160 species scattered across the globe, about 120 of which are found in Australia.
The number of Tasmanian species is ten, plus one. The ‘plus one’ refers to a new species which was described in 2014, but has yet to hit the field guides. Technically this new one – Drosera murfetti isn’t so much a newly found species, but an overlooked one. It was always lumped in and confused with Drosera arcturi. They both look very much the same, except a slightly different flower structure. So let’s make it 11 species in Tasmania.
All Drosera species are carnivorous terrestrial herbs. Not herbs in the sense that you would put them in your pasta sauce, but herb meaning herbaceous. Herbaceous meaning not woody. They can be either perennial (grow back each year) or annual (life fast die young all in one year). Majority however are perennial.
Some species have a fibrous root system and others develop rhizomes and/or tubers. This is where my research has pulled me up short. The Flora of Tasmania has some species descriptions as ‘an erect rhizome arising from a globose tuber’. Both are modified stems, both are slightly different. If there are any Drosera root system experts reading this, help me out. For now I shall put this in the ‘things to research further’ pile.
What they do all have in common though is their ability to trap and digest small insects, turning them into a soluble food to gain the extra nitrogen they need to grow. They do this using glandular hairs with a sticky glob of fluid at the end which protrude along their leaves. As the insect wanders across, it gets all stuck and tangled, the leaf them curls in and gets to work digesting.
Drosera distribution across Australia
Roughly 75% of all known species are found in Australia. Yes. 75%. That is a massive number, hence Australia being known as the centre of diversity in the Drosera genus. We are Drosera special. South America and southern Africa also had a fair few species, but nowhere beats Australia land. We also have quite a few other carnivorous plants, but that is a story for another day.
Pygmy Drosera, which are a section of Drosera grouped together because of their tiny size, are mainly found in Western Australia. Apparently they are all endemic to W.A (only found there) except for D. pygmaea. There seems to be quite a large number of species which are endemic to Australia as a whole. Which is not hugely surprising, being a big island, and having spent a damn long time being isolated from the rest of the world. Drosera are found pretty much all over the country, not too sure about Northern Territory, as I haven’t found any information which mentions it. If you know something about Northern Territory carnivores, let me know. Not the crocodile variety of carnivores though, I think we all know about those ones.
The Tasmanians
Drosera in Tasmania can be found across a wide variety of habitats. From dry grasslands, heathlands, alpine herb fields, acidic bogs and wetlands. From near sea level, right up to the tops of mountains they are a very diverse species who have evolved to fill a range of specific niches.
If you are a keen and regular bushwalker you would probably be familiar with at least a few of our Drosera species. There are many popular places where they are quite common. If you spend time wandering the cold mountain tops such as the Tarn Shelf at Mount Field, Hartz mountains, Cradle Mountain or other similar areas then you are bound to come across D. arcturi. I remember seeing it for the first time amongst the cushion plants on Newdegate Pass and it’s a brilliant little plant, with its leaves sticking up ready to catch a passing insect.
Peter Murrell Reserve down at Kingston is always a great place to get a Drosera fix. If you have ever wandered around looking for orchids then you are bound to have found them. Most commonly seen (by me anyway) are D. peltata and D. auriculata. These two look very similar, but remember that D. peltata has little hairs on it’s sepals (thats the green leafy bit that surrounds the flowers) and D. auriculata doesn’t have hairs.
Hanging out around peat bogs and generally boggy wetlands chances are you will come across D. pygmaea. I’m going to say this is one of my favourite ones I have found growing, but they are all favourites really. Doing field work in a boggy, stinky marsh at Bruny Island we came arounds millions of these. Actual numbers weren’t taken, so millions could be an over statement, but they were everywhere. Tiny little red rosettes about 10mm wide dotted the edges of the wetland. They were so cute and wonderful I could have sat there all day with them. Looking back, I think I did spend a lot of time sitting there enjoying them when I should have been doing soil sampling…
For a list of all Tasmanian Drosera (minus number 11) you can head over to the Flora of Tasmania page. They have an in depth description of each species and a key to help you work out who is who in the hundred acre wood.
Making baby Drosera
Whilst reading all the various webpages regarding cultivating Drosera as a house plant, I learnt that they produced gemmae, which I had no idea that plants even did that! When i think of gemmae I think of the gemmae cups on Liverworts, not flowering plants.
Gemmae is a way of asexual production, which is pretty much cloning yourself. A gemma, is a little ball of cells, or propagule, which is produced by the parent plant. The gemma becomes detached from the plant and travels off to develop into a new individual. In a lot of liverworts the gemmae are produced in little cup like structures. When a drop of water flushes them out they are dispersed and can colonise new areas.
Not all Drosera produce gemmae. It is very common amongst the pygmy Drosera, which are mainly found in Western Australia. During summer the plants go into dormancy, all their leaves die and they all but disappear. When autumn hits and it’s not so blisteringly hot, growth picks up and gemmae are produced. In the case of Drosera the gemmae are little modified leaves, which act in same way as they do in liverworts. When a rain drop lands on them they are flung out far and wide where they produce new plants. Seed production is pretty limited on the Pygmy sundews apparently, pehaps that is why they are so good at the asexual means of making baby Drosera… Maybe, that’s purely speculation on my part.
Drosera in cultivation
Cultivation is what got me here, lost in the world of Drosera, finding out new things and discovering the vast number of species we have here in Australia. I believe the two species I have are D. spatulata (spoon-leaved sundew) and D. capensis (Cape sundew).
D. spatulata is a species found in Tasmania which is widely grown in cultivation. It flowers and sets seed readily, so is a great one for propagation. Hard to kill apparently and is the easiest and least fussy of all Drosera. Currently mine are all a beautiful shade of green, when they ‘should’ be a vibrant red. All this means is that they haven’t been growing in enough light. They are still sending up flower shoots, so it can’t be to detrimental to their health. If you look through carnivorous plant sites there are many varietys and cultivars available.
D. capensis is a species from subtropical South Africa. Another one which is widely grown in cultivation, and from all accounts, sounds like a fairly easy one to grow. As with most plants which are grown as ornamentals, there are numbers cultivars on the market.
I can’t really comment a great deal on the cultivation, because I’ve only been at it for a couple of months and I am still learning. What I have learnt though is that D. spatulata is pretty damn easy to grow. I have some in closed terrariums, some in the top of other carnivores and they all seem to be doing well. Early on, before I knew that most carnivorous plants don’t like your normal potting mix, I did plant some in terrariums with it. Technically they were stuck in the a tuft of moss which was growing on the potting mix, but so far they are ok. Perhaps when their roots get down a bit they may hit some nutrient rich soil and turn their toes up… Time shall tell…
Responsible Drosera growing
Carnivorous plants are popular and collectable. They grow wildly across most continents, and chances are you live somewhere nearby to a population. I know it could be very tempting to go out and grab a few here or there to try and grow at home. Don’t be that guy.. or girl.. Don’t be that person.
Plants from the wild, no matter what they are, need to be left in the wild. Not only would the chances of keeping them alive be slim, removing them from their natural habitat slowly degrades that habitat. You might think ‘but it’s just one plant, that won’t matter’ but it does matter. If we all went out and took ‘just one’ then the population would get decimated very quickly, and everything else that depends on that population would crash.
I was recently listening to an old podcast from ‘In Defence of Plants’. They were discussing Nepenthes, and how the natural populations have been completely screwed due to people harvesting them for the collector trade. To the point where there are species which once were abundant and are now only found in peoples greenhouses. Not cool. Not cool at all. I can’t for the life of me work out how to link to the episode, but hit up the website and search for episode 74. Nepenthes and other botanical treasures with Stewart McPherson. Worth a listen. While you are there just subscribe to the podcast, you will thank me.
So remember, purchase wisely. Make sure you are buying from reputable stores who propagate themselves and don’t ruin ecosystems.
Further reading and references from where I read…
Flora of Tasmania – Great resource for local plant info and keys
Key to Tasmanian Dicots – My go to page for plant id. Although needs updating
In Defence of Plants – Curing plant blindness one episode at a time. Possibly the best podcast I listen to (Next to The Field Guides) When I grow up I want to make a Tasmanian plant podcast as good as this one…
Lowrie, A. and Conran, J.G., 2014. Drosera murfetii (Droseraceae): a new species from Tasmania, Australia. Journal of the Adelaide Botanic Gardens, pp.7-21.
Book: Tasmania’s Natural Flora (Which every good Tasmanian should own)
http://www.sarracenia.com/faq.html
And other pages whose tabs I closed before I noted the url… oops
All photos are taken by me at various places around Tasmania.
