Thursday, August 23, 2012

This plant's so cool it's Ice!

Species name: Hylotelephium spectabile (formerly Sedum spectabile)

Common name: Ice plant

Location: Ontario

This species of succulent plant is native to Europe and is one of the few examples of succulent plants that can survive in Canada. This plant is technically a perennial, and there are select locations that the ice plant survives as a perennial, but in most locations it is grown as an annual (much like tomatoes and potatoes; technically those are perennial plants, too!). Once the flowers open they are pink to white depending on the cultivar, and the texture of the leaves is indicative of the health of the plant. The rubberier the leaves, the more water they contain, and the more healthy the plant. This is much the same as one of its houseplant relatives, the Jade plant; many indoor plant growers use the thickness of the leaves to determine when the plant needs water (which, surprisingly enough, is only once every two to four weeks depending on indoor humidity!).

This species of plant is another example of how DNA sequencing has shown that plants that are superficially similar to each other might not actually be related at all. Like it's close relative the showy stonecrop, which you can read all about HERE, this species of plant used to be in the genus Sedum because of the five petals in each flower, and ten stamens (stamens run along the mid-vein of each petal, and again perfectly between each petal). There was also that these are succulent plants, the general shape of the leaves and the colour of the flowers that both genera have in common which led botanists to believe all of these species were part of the same genus. This is just yet another example of the saying "morphology doesn't always predict phylogeny;" in other words just because two things look the same doesn't mean they're related to each other. In Biology, we call these traits "homologies" (also "analogies" depending on the circumstance) which are two different characteristics that have arisen separately but have converged on a similar morphology due to the characteristics' function. A great example of this in the animal kingdom are wings. Bird wings and bat wings are very different when you look at the bones of each structure, but they still look very similar because both bird and bat wings are used for flight.