Monday, November 16, 2009

Second Rainy Seedling 2009

16 mm wide, photo taken 11/14/09

What's this seedling? It has large, thick cotyledons (seed leaves) with a slightly rough surface. First true leaves have pointed tips, spiny edges and white prickles on the surface of the blade.

A definition of cotyledon from the Facts on File Dictionary of Botany: "The first leaf or leaves of the embryo in seed plants." For our purposes in identifying seedlings, we are looking at the cotyledons that emerge from the seed and are the first leaf-like structures that you see.

The cotyledons of mystery seedling #2 are thick which means they are filled with stored food to spur the growth of the seed-bound embryo upon release from dormancy (usually means the seed has been soaked with moisture). They are also green which means photosynthesis starts immediately upon germination to provide growing energy. This is a plant that is likely to grow quickly either underground or above ground or both.

There are two cotyledons which means this is a plant in the subclass of Dicotyledonae, a large category that contains most of the flowering plants we most readily recognize as opposed to the Monocotyledonae subclass which includes the grasses and grasslike plants that only have one cotyledon. Other features that people most often recognize: Dicotyledons have broad leaves with branching veins (think lettuce or maple leaves), whereas Monocotyledons have narrow leaves with parallel veins (think grass or lily). Don't worry too much about these big names, just remember that two cotyledons means it is not a grass, and you are closer to guessing what this seedling is.

Sometimes people casually use the term "dicot" to mean seedling. They might say, "In the winter, we use the propane torch to kill the dicots." I recommend you do not use the word dicot in this casual fashion because it could be interpreted as meaning that you are going to control all the gazillion of plant species that are in the Dicotyledonae subclass, and that is an exhausting thought. Try to use the words dicot and cotyledon for separate purposes. You might say, "The propane torch works best on plants that are still in their cotyledon stage." Or, "I noticed that seedling is a dicot, so it can't be any of the native grasses we seeded here."

On weekends, I will post the identification of any of the mystery seedlings from that week. If the deer don't eat the seedlings in the meantime, I will also post photos of their growth over one week of sunny weather.

See also: The Facts on File Dictionary of Botany, Elizabeth Tootill, General Editor, Stephen Blacmore, Consultant Editor, Market House Books Limited, 1984.


  1. I like this game Cindy! It's me, Heather Brady.

    I think this one is a thistle, maybe a milk thistle, or Italian thistle.

    Can't wait to read the answer.



  2. Hi, Heather. Just recommended someone call you today. I have a tough seedling coming up next. I'm not even positive what it is and was going to wait to post it, but now I think I will just go for it later in the week. go plant detectives!

  3. Nom nom. Thistle, prolly Italian but possibly milk. Colors change as they get older. Seed leaves (not true leaves) are a nommy munch while you are hiking and then you are weeding as well, in a way!!! Now don't be funny and pull a Venus thistle on us or something...


Comments let me know to keep on sharing what's happening at the Dipper Ranch. You can either use an existing account or choose "Anonymous" by clicking the arrow after the "Comment As" box. Your comment will appear after a delay to allow screening of spam.