Wednesday, August 8, 2012

Let's play a game: ID this plant!

UPDATE: The general consensus reached for the ID of this plant is Thymus pulegioides. This ID still doesn't feel right to me, but since I'm not a plant expert and the two that both came up with this ID are, I'm going to defer on their expertise and say that's what it is. At least, something close. The common name of this plant is broad-leaved thyme and sometimes lemon thyme (although, that common name is applied to just about any plant that looks like thyme that smells even remotely lemony, which is 5 or 6 different species). Thanks for playing, everyone! And thanks for Sophie and Matthew for the help via Twitter.

Species name: Lamiaceae sp.

Common name: plant in the mint family

Location: Ontario

I've been toying with the identification of this plant for a few days now, and I just can't seem to get it right. So instead of me identifying it, I'm opening the floor. Know what this plant is? Drop me a line in the comments section!

Instead of talking all about one particular species, I figured I'd talk about at least what I know for sure to be true: this plant is most definitely in the mint family, or the Lamiaceae. There are two major distinguishing features for this family. The first are the flowers: the petals are fused at the base into a tube-like structure, and at the end are modified into a large top petal and an even larger bottom petal. Sometimes, as in this example, the bottom petal retains morphological characters that would lead you to believe it came from the fusion of three petals (which it did) in the form of lobes on the petal edge. The second major feature that leads me to the general identification of this being a plant that's a member of the Lamiaceae is pointed out by the arrow in the bottom photo, the square stem. If a plant is in the mint family, it has a square stem. For some species, you have to use your imagination a bit more than others for how this rough round shape is actually a square, but more often than not the stem is a clear square shape in cross-section.

The leaves of this plant are smooth on both the top and bottom surface, and the leaves are incredibly small and lack teeth, all unusual characters for the mint family. One of the reasons why members of this plant family are so aromatic when the leaves are crushed is because of the tiny hairs on either the upper or lower surface of the leaves (or sometimes both) called trichomes that have a tiny oil droplet at the tip. This oil droplet is meant to deter herbivores, since in large amounts they taste downright nasty, and in fact most are carcinogenic. You don't have to worry about getting cancer from basil or oregano, though! Since humans are so large, you would literally have to eat a pound of basil a day for the chemicals in the essential oils to have any negative effect. The very reason why we started to use herbs and spices in food is to exploit these essential oils, which even in small amounts have very potent antimicrobial effects, and to kill food-borne bacteria before consuming food prior to refrigeration.