Inside of a Seed: Two Monocots

“Seeds are travelers in space and time – small packages of DNA, protein, and starch that can move over long distances and remain viable for hundreds of years. These packages have everything they need not only to survive, but also to grow into a plant when they encounter the right conditions.”      The Book of Seeds by Paul Smith

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As illustrated in last week’s post, the mature seeds of dicots – depending on the species – can be either with or without endosperm (a starchy food packet that feeds a growing seedling upon germination). Seeds without endosperm store these essential sugars in their cotyledons. Monocotyledons (or monocots, for short) are a group of flowering plants (i.e. angiosperms) whose seedlings are composed of a single cotyledon. With the exception of orchids, the seeds of monocots always contain endosperm.

The first of two examples of monocot seeds is the common onion (Allium cepa). The embryo in this seed sits curled up, surrounded by endosperm inside of a durable seed coat.

If you have ever sown onion seeds, you have watched as the single, grass-like cotyledon emerges from the soil. The seed coat often remains attached to the tip of the cotyledon like a little helmet as it stretches out towards the sky. Soon the first true leaf appears, pushing out from the base of the cotyledon. The source of this first leaf is the plumule hidden within the cotyledon.

The fruit of plants in the grass family – including cereal grains like wheat, oats, barley, rice, and corn – is called a caryopsis. In this type of fruit, the fruit wall (or pericarp) is fused to the seed coat, making the fruit indistinguishable from the seed. The embryos in these seeds are highly developed, with a few more discernible parts. A simplified diagram of a corn seed (Zea mays) is shown below. Each kernel of corn on a cob is a caryopsis. These relatively large seeds are great for demonstrating the anatomy of seeds in the grass family.

In these seeds there is an additional layer of endosperm called aleurone, which is rich in protein and composed of living cells. The cells of the adjacent endosperm are not alive and are composed of starch. The embryo consists of several parts, including the cotyledon (which, in the grass family, is also called a scuttelum), coleoptile, plumule, radicle, and coleorhiza. The coleoptile is a sheath that protects the emerging shoot as it pushes up through the soil. The plumule is the growing point for the first shoots and leaves, and the radicle is the beginning of the root system. The emerging root is protected by a root cap called a calyptra and a sheath called a coleorhiza.

Germination begins with the coleorhiza pushing through the pericarp. It is quickly followed by the radicle growing through the coleorhiza. As the embryo emerges, a signal is sent to the endosperm to start feeding the growing baby corn plant, giving it a head start until it can make its own food via photosynthesis.

corn seeds (Zea mays)

Up Next: We’ll take an inside look at the seeds of gymnosperms.

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2018: Year in Review

Another year has passed, which means it’s time again for a Year in Review. As I have done in the past, I am including links to a selection of posts that came out in 2018. Most of these posts are part of ongoing series. You can find the rest of the posts from 2018 in the Archives widget on the right side of the screen (or at the bottom of the page if you are viewing this on a mobile device).

Among many memorable happenings this year, the one I feel most compelled to highlight here is a short radio show that a friend and I started doing on Radio Boise, our community radio station. The show is called Boise Biophila, and each week Casey O’Leary and I spend about a minute each talking about something biology or ecology related with the goal of encouraging people to get outside and take a closer look at the natural world around them. After the shows air, I put them up on our Soundcloud page for all to hear for years to come. You can follow us there, as well as on our Facebook page.

Ficus carica via PhyloPic

In the spring of 2018 we set up a Donorbox account, which is a simple way for people who enjoy Awkward Botany and want to see it continue to give us a little financial encouragement. We received several donations at that time, and we are very grateful to those that contributed. But just like public radio or any other organization that would like to receive your support in the form of money, we continue our plea. If Awkward Botany means something to you and you feel compelled to share some of your hard-earned dollars with us, we are happy to receive them and promise to put them to good use.

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Money aside, a major contribution you can make to the success of Awkward Botany is to share it with your friends. Spread the word in conversation, through the postal system, over the phone, or through one or more of the myriad social media platforms. However you choose to share is none of our business. We are just happy that you do.

You are also encouraged to follow our various social media pages: Twitter, Tumblr, and Facebook. Above all, keep reading. We have lots more posts in the works for 2019, and we wouldn’t want you to miss out on the fun. Our appreciation for plants and the natural world is a constant, and we hope you will continue to share in our botany nerd revelry throughout the coming year.

Fragaria vesca via PhyloPic

Book Reviews:

Botany in Popular Culture:

Tiny Plants:

Field Trip:

Eating Weeds:

Two-parters:

Guest Posts:

Recent Happenings at Awkward Botany Headquarters

Radio Show

Writing is the method of communication I am most comfortable with; however, several months ago a friend of mine talked me into starting a tiny radio show. The premise was immediately appealing: spend about a minute each talking about something biology or ecology related that people living in the Boise area can relate to. The goal being to encourage people to get outside and take a closer look at the natural world around them. The show would air on Radio Boise, a community radio station broadcasting from the basement of a historic downtown building.

Speaking into a microphone is something I generally avoid, but with Casey O’Leary as my co-host, I knew it was going to be okay. Now that we are about three months in to our weekly show, I am feeling pretty good about it. We are not professional broadcasters by any means, but we have fun talking about the nerdy things we love. Our show is called Boise Biophilia, and it airs at various times throughout the week on Radio Boise. I’ve also started putting episodes online after they have aired. You can check those out here.  Thanks to Sierra, we have a Facebook page as well.

Boise, Idaho and hot air balloons (photo courtesy of Shelley Jacks)

Awkward Botany Store

For years now I have wanted to make some Awkward Botany merchandise. Not that any of us really need more stuff, but I like having stickers, buttons, and other little things from my favorite projects and people. Perhaps you do, too. If Awkward Botany is something you enjoy, maybe you’d like to get your hands on some Awkward Botany branded stuff … or maybe you don’t. Either way, I have made some silly pocket notebooks with the Awkward Botany logo on them (thanks again, Franz Anthony!), and I am making them available for sale at this Etsy store. I have limited quantities at the moment, and the first batch is a little rough (mistakes and all). But if there is interest, I’ll make more.

It would be fun to create other stuff to sell, so if there is a particular Awkward Botany branded item you would like to see, please let us know in the comment section below.

Support Awkward Botany

I’m not fond of asking people for money, so I don’t do it often. However, to write the level of well-researched posts that I like to write requires a significant amount of time and resources. If you enjoy reading Awkward Botany and find this content valuable, please consider giving us a “High Five!” — essentially $5 (one time or monthly). Monthly helps us budget and plan ahead, so an extra thanks if you decide to give that way. What can $5 possibly do, you might ask?

Well, $5…

  • is 1/5 the cost of most books
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You can visit our Donorbox page to cheer us on, or click the ‘donate’ button below.
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Money aside, the biggest contribution you can make to the success of Awkward Botany is to share it with your friends. You can spread the word in conversation, through the postal system, over the phone, or via a social media platform of your choosing. You should also follow our various social media pages: Twitter, Tumblr, and Facebook. And speaking of Facebook, thank you to the thousands (and yes, I said “thousands!”) of new followers we have received in the past few weeks. You are blowing our minds.

Now go outside and interact with something green.