Biopoetics: Crassostrea virginica

Photo by Jeremy Keith entitled ‘Oysters’ (Attribution 2.0 Generic), link through photo

First, a big shout out to all the sins for publishing this poem in their inaugural issue; you can find the link to the poem here, or listen to me read it aloud here.

Crassotrea virginica is one of five species of oysters. C. virginica is an Atlantic-dwelling species and the northern-growing varieties, living in colder waters, are known for their intense briny flavor. They are the type of oyster that a person eats, which means that they will not produce pearls. Pearl-producing oysters are from the family pteriidae (as opposed to eating-oysters from the family ostreidae) and generally live deeper in the ocean than eating oysters.

Oysters, eaten raw, are considered to be a luxury food – just as pearls are also a symbol of wealth. I found this juxtaposition, of food and inedible material both based in the same type of shellfish and also symbols of riches, to be really fascinating; it was the socioeconomic context of oysters that really pushed this poem into being more than the science.

It’s said that oysters taste better in the winter as they can be kept cold and fresh easily from the moment they’re harvested. Oyster shells, filled with calcium, can theoretically help plants grow in gardens if used as fertilizer; the calcium can reduce soil pH, add need nutrients to the soil, and strengthen cell walls (supposedly – it’s up to you if you trust this source). I wouldn’t recommend just chucking the shells into the garden though; it seems likely they would be difficult for your average soil-living microbe to break down. Crush your shells up first, and you’ll get some healthier, happier plants!

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Biopoetics: Sunleaves

Photo by Kristine Paulus entitled ‘Acer saccharum (sugar maple)’ (Attribution 2.0 Generic), link through photo

First published in Gandy Dancer, 4.2, Spring 2016. As a new feature, you can now hear me read aloud the poem here and I’ve updated the past Biopoetics posts with their readings.

This poem is a lot more abstract and less concrete-science than other past poems, but it deals with the season of ‘fall’ for trees. When I first began working on this poetry series and thinking about trees more deeply, I came to the conclusion that trees wouldn’t obey our seasons. So I created what I thought were important ‘seasons’ for trees: Sunleaves, Deepnight, Sapriver, Budbreak, and Windborne. Sunleaves occurs when the leaves turn red and fall off the trees.

As the days get shorter, less chlorophyll production occurs allowing other colorful chemicals like carotenoids (orange) and anthocyanin (red) to be ‘uncovered’. The fiery, gold color of fall leaves isn’t ‘produced’ in the fall perse, instead it’s revealed as the green of the chlorophyll fades away.

So the chloroplasts are becoming ‘ashen’, losing their green color as the days become shorter; at the same time, abscission cells (often with modified, weaker cell walls) are being formed where the leaf meets the branch of the tree; this means that, eventually, one hard gust of wind will knock the leaf off the branch. These withering, brittle leaves are thirsty, dying because of a lack of water and nutrient exchange with the tree itself (while leaves can produce their own energy through photosynthesis, they need water from the roots of the tree to survive).

Some parts of the leaf will be actively broken down as the leaf slowly dies, its grasp on the tree being weakened by the abscission cells, until the tree is finally rid of all the leaves and even the red and golden colors are gone, decomposing into the brown leaf litter that covers the forest floor.


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Biopoetics: Dicotyledons

First published in Mind Murals, page 10, Spring 2016. Listen to it read aloud here.

Photo by George Wesley and Bonita Dannells entitled ‘Maple seeds – the samara’ (Attribution-NonCommercial-NoDerivs 2.0 Generic), link through photo

The poem is the only shape poem I’ve ever attempted, but I was inspired by the uniquely beautiful shape of the double samara – the ‘helicopter’ fruit. These seeds are characteristic of dicots (short for dicotyledons), so named because they have two (di) cotyledons (small leaves inside the seed that are the first “leaves” to appear after germination).

In sugar maples, these cotyledons store food/nutrients for the seed and, once the seed germinates, photosynthesize until true leaves can grow. I feel the poem is a bit misleading (unintentionally) where it says ‘abs orb nutrients’; I meant only that nutrients were packed into the cotyledons as they were formed – that they absorbed nutrients as the fruit grew. I learned later that some monocots (mono = one cotyledon) actually have cotyledons that absorb food stored elsewhere in the completely formed seed. In comparison to the story of monocots, I feel this line could be easily misconstrued.

When the germinated seedling gains its first true leaves, they appear broad and almost rounded compared to the cotyledons thinness and do not yet have the class sugar maple leaf shape. Following the left side of the poem, we learn that sugar maple seedlings can germinate in a thick layer of ‘humus’. Humus is a dark soil composed of decaying plant and animal matter, making it nutrient rich and good at retaining moisture while also remaining well-drained. It’s generally considered an excellent soil type for sugar maple growth.

Following the right side of the poem, we see the seed germinating. The radicle “root” is the first part of the seedling to emerge during germination. The radicle pushes down through the seed coat and snakes through the soil to find water and set up a root system, eventually growing large enough to be the tree’s ‘tap root’. The radicle grows via its apical meristem (a region of actively dividing cells that grows the tips of shoots and roots) at its tip, helping it to bury deep into the soil and look for water. This water allows for the rise of other tissues as the seedling grows larger (like true leaves, sweet for their photosynthetic production of carbohydrates). Each seed generates one radicle root and it is white in color since, like other roots, it stays underground and does not photosynthesize.

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BioPoetics: I: Matured

First published in Mind Murals magazine, page 11, in the Spring of 2016. Listen to it read aloud here.

This poem blossomed out of I: Seeding in which I wrote about the way a strong wind can affect the shape of a growing sapling. Shortly after writing this poem, I learned that sugar maple trees are primarily wind-pollinated, not pollinated by bees as I had originally been led to believe in my previous research (this discovery is relatively new; Cornell’s website uses materials from 1996 which indicate bees pollinate sugar maple flowers but more recent studies show it’s actually primarily the wind). I felt it was necessary to write a follow-up about the relationship between the wind and the trees, when they grew older.

Photo by Kent McFarland entitled ‘Sugar Maple (Acer saccharum) flowers’ (Creative Commons Attribution-NonCommercial 2.0 Generic License), link through photo

Sugar maple trees begin to produce flowers around thirty years of age (this is the minimum for fruit-bearing) and the process of flowering is known as inflorescence. During good years (usually cyclical every two to five years depending on environmental conditions), the flowers fill the tree canopy so heavily that the tree takes on a yellowish cast. Most sugar maple trees will produce flowers of entirely male parts, those of entirely female parts, and those that have both male and female parts.

Pollen grains are (i.e. male spores) and can be found in the pollen sac, or microsporangium, before being distributed by wind (in the case of sugar maples). It’s important to note that all pollen grains are spores, but not all spores are pollen grains as there are also female spores (megaspores). Primitive plants and seed-bearing plants utilize spores differently in reproduction.

If a sugar maple flower is pollinated, it develops into a fruit – what we would colloquially call a ‘helicopter seed’ but can also be called a double samara. After pollination, the flower ripens into a fruit for about two weeks before each samara falls off the tree and is blown by the wind all over the land. The ‘winged’ shape of the samara lends itself well to being carried by wind through forests and fields, over snow and sand. Eventually, the samara settles and germinates if the conditions are right.

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Biopoetics: I: Seedling

First published in Mind Murals, page 9, in the Spring of 2016. Listen to it read aloud here.

Biopoetics will be a series of posts in which I explain the science that went into my biology-tinged poetry, in 400 words or less, no matter how heavy or light the poem is on science. I: Seedling arose from looking at a picture of a tree, seriously bent by the force of the wind.

When a seed falls off a sugar maple tree it is blown around by the wind and will often land in ‘leaf litter’ – accumulated leaves on the bottom of a forest floor – or ‘humus’ – an organic substance made up of decaying plant and animal matter. Humus retains water and provides nutrients, so sugar maple trees grow well in humus.

When the seed germinates, it sends roots downward to obtain water and a shoot (generally white, like the roots, at first) up through the soil to seek the sunlight. The shoot turns green and gains leaves only after breaking the surface of the soil and being subjected to environmental forces like sunlight and wind.

Photo by Steve Evans entitled ‘South England Coast’ (Creative Commons Attribution-NonCommercial 2.0 Generic License), link through photo

Strong winds can ‘reground’ a plant, by making it grow nearly horizontal; young plants are particularly susceptible to this as they don’t have significant girth to help them resist the force of the wind. This can hurt plants by reducing their vertical (primary) growth, and thus their ability to compete with other plants for sunlight. Wind can also hurt a plant’s ability to grow by replacing ‘wet’ air around the leaves with drier air [causing increased rates of transpiration (basically just water lost to air)], by breaking thin branches or ripping off leaves [thus decreasing photosynthetic potential], and by pulling trees so hard their roots stretch. This last problem increases water stress for the plant as the root-soil connection is broken and less water is absorbed from the surrounding soils (it can also break the roots).

As a tree grows, it obtains girth by growing its vascular cambium (the dark rings in a tree stump that are responsible for producing that year’s xylem and phloem tissue, the light part of the rings). Water stress (basically not enough water) caused by the wind can make a tree thinner than average for its years; periods of water stress lead to smaller cells and/or less cells produced during the growing season, creating thinner rings and thus a more lean-looking tree. By growing wider, year after year, the tree can become more resistant to the structural stress of the wind as it ages.

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