Thursday, May 16, 2013

The afternoon primrose

Species name: Primula sp. (a garden hybrid of unknown origin)

Common name: primrose

Location: Ontario

Primroses are another great example of why I hate common names. The evening primrose (profiled in a blog post that you can read HERE), is completely unrelated to species in the genus Primula, also called primroses. Sure, they look a little similar (perhaps not the evening primrose compared to this garden hybrid, but some other Primula species), but that's about it. Species of primrose in this genus are native to a wide variety of locations on almost every continent (Australia seems to be excluded from the list) but with the vast majority of the species in the genus native to the Himalayas. Since this garden hybrid (which is actually quite commonly grown) has an unknown parentage, meaning the two or more species that were hybridized to create this cultivar, so I decided to play it safe and call it a non-native species.

I think this species illustrates the concept of a weed perfectly. There is no real definition of a "plant weed," nor are there truly good examples of weed species at least in the common sense of the word. A weed is simply a plant that is growing in a place that we don't want it growing. A plant that is purposefully planted in one garden might be their next-door neighbour's weed. You can probably guess that most weeds are non-native species, only because those are the plants that are most likely to out-compete their neighbours since there are no pathogens to keep their populations in check. This primrose is a great example of a weed in our garden. I have no idea who planted it in the neighbourhood, but one spring it all of a sudden showed up. I ripped it out, but not until after it had gone to seed so now it comes back every year. I wish if it was going to grow it would do it more quickly and make a nice little patch of it that we could put a fence around to keep it contained, but it seems to like being the size that it is (about 10 cm x 10 cm and 4-5 cm tall). I'll refrain from pulling it out this year and see what happens.

I don't think it should come as a surprise to any of my faithful blog readers that I'm a bit of a skeptic when it comes to classification of species. This is probably because of the results I've found in my own work: apparently we're not very good at defining species of fungi at all, and many things that we thought were "species" are only morphological variants. Even more numerous is the trend the other way: many things that we thought were morphological variants are actually species. It's amazing what happens when you start to sequence a group's DNA and analyze the relationships between species! The genus Primula is a great example of this. There are over 500 species in the genus, some of which are so drastically different morphology-wise (and even habitat-wise, which should tell you something about their evolutionary relationships...) that I find it incredibly hard to believe they're in the same genus. With a more thorough investigation of these 500 species and a comprehensive analysis of the group's evolutionary relationships, it wouldn't surprise me if Primula ended up being divided into 25 or more separate genera. Might even be a fun post-doctoral fellowship... :)

Internationally primrose species have been used as medicinal plants for centuries. In fact, they have so many uses that they just might be a miracle plant should all of these uses prove to be effective in clinical trials. The roots of the plants are prepared in either a salve or a tea to treat any kind of cough (pneumonia, bronchitis, common cold, emphysema, etc.), the leaves are used in a tea to treat any kind of head-related ailment (dizziness, headache, stroke, sleeplessness, paralysis, etc.) and the flowers as a vitamin supplement (rumoured to contain high amounts of vitamin A and vitamin C) as well as any kind of digestive-related problems (diuretic, spasmolytic, and sedative). That's a whole bunch of uses for one tiny plant! I find it hard to believe that it could be effective against everything that might ever ail you, but you never know. With a species diversity in the genus argued to be at 500 species, if each one had a single use that's a whole lot of uses! It's also a good example of a general rule in botany and "plant gathering as agriculture": don't ever eat anything or use something as a medicinal plant if you're not absolutely sure about the intended use. If you use the wrong primrose, your headache might turn into a dizziness spell or convulsions!