Everything You Wanted to Know About Plants Part 2: The Conquest of Land

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Everything You Wanted to Know About Plants Part 2: The Conquest of Land

Last week, I introduced the concept that green algae (but not their brown, red and gold counterparts) are actually plants that outnumber the leafy things we're all familiar with. You were probably left wondering how one gets from Ulva and Volvox to a redwood. As it turns out differences between land plants and green algae have everything to do with the different environmental challenges they face.

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Everything You Ever Wanted To Know About Plants (And More): Part 1

All throughout fall we at Our City Forest receive panicked emails from residents about their trees. Everywhere it seems that young, healthy trees planted earlier this year are dying. People blame lots of things for this, the drought, insects, poor soil, or even Our City Forest. More often than not the blame rests on autumn. In New England the height of the leaf season has come and gone. The hills are no longer awash with red, yellow and orange, or smell of leafy petrichor, crisp on cold winds. Here in San Jose, deciduous trees (trees that shed leaves) are at the tail end of the fall color season, entering their winter dormancy.

It's hard to believe that this happens every year. 

It's hard to believe that this happens every year. 

We don’t blame people for not knowing about autumn. Many people in the region come from subtropical areas with long growing seasons. Many more have no direct experience with plants, trees and the peculiarities of seasonal changes. This is the first part of a multi-part series on plants, plant science and arboriculture to shed light on our photosynthetic friends (in a metaphorical sense).

Plants love light after all. 

Plants love light after all. 

When I say “plants” chances are you picture big, leafy trees, flowers, shrubs and maybe some of you think of ferns and moss. All of these images are correct but incomplete. Land plants, the plants most humans are familiar with, actually constitute a small fraction of the diversity of the Plant Kingdom.

The vast majority of plants, by population, are actually aquatic, green algae. (Flowering plants dominate other plant types in terms of species richness). Like the plants you're familiar with, they come in a variety of shapes and sizes. Most are microscopic but many are visible to the naked eye and come in a variety of shapes and sizes. From nesting, spherical Volvox to leafy, filmy Ulva green algae dominate the plant kingdom. (Not kelp though, that’s brown algae).

The variety of green algae in the sea is stunning 

The variety of green algae in the sea is stunning 

So what makes a plant a plant? All plants, as it turn out, have similar cellular structure. Plant cells are eukaryotic, meaning they have an array of membrane-bound organelles, including a nucleus. All have cell walls made of cellulose, which provide the cells with structure and protection.

A plant cell. Note the cell wall, vacuole and chloroplasts 

A plant cell. Note the cell wall, vacuole and chloroplasts 

Plants also have chloroplasts, specialized double-membrane organelles for photosynthesis containing “a” and “b” type chlorophyll pigments. Chloroplasts are thought to have arisen from symbiotic cyanobacteria that lived within the common ancestor of plants billions of years ago. Scientists have discovered they have their own, unique genome like mitochondria. Red and brown algae have chloroplasts also but their chloroplasts use different pigments and have more membrane layers. (They also go through distinctive developmental phases that plant cells do not go through). Plant cells also have large, central storage vacuoles that maintain the cell’s shape via turgor pressure.  

Wilting is in part caused by a lack of tugor pressure as the leaves lose water. 

Wilting is in part caused by a lack of tugor pressure as the leaves lose water. 

There are approximately 300,000-400,000 species of plants on Earth and more are described every year by botanists, ecologists and microbiologists. Almost 250,000 of these species are flowering plants (angiosperms). The next post in this series will focus on plant anatomy and physiology (did you know plants have hormones and that they do really rad things?) and after that we’ll focus on tree-specific topics. Hope you enjoy. 

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Why Rent A Tree This Holiday Season

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Why Rent A Tree This Holiday Season

I have a lot of memories tied up in the sensoria of real holiday trees. The smell of pine evokes sap on my fingers. The feel of spruce in my hands puts me back in New England with November snow crunching under my boots as I pick around half-buried stumps, the smell of gasoline and sound of chainsaws. Memories beget more memories. Harry Connick Jr croons out of the stereo while dad untangles strings of lights. Mom corrals us as my siblings and I tear through the boxes of  ornaments to find our favorites. My brother’s, a firefighter dog with a Christmas present. Mine was a chimpanzee Santa with a sleigh of bananas.

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How the Lawn Grew Across America and Why That Needs to Change

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How the Lawn Grew Across America and Why That Needs to Change

There’s a growing anti-lawn sentiment in the drought-stricken West. NevadaArizonaNew Mexico and California each have programs in place to pay homeowners to replace lawns with xeriscaping (drought-tolerant landscapes). I’d heard of these programs when I lived in New York. Driving through trackless desert, salt flats and blonde, high-plains I couldn’t help but wonder how we ever thought to impose lawns on these landscapes in the first place. Where did lawns come from?

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Honoring a Tree Hero

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Honoring a Tree Hero

When we think of Dave Fadness, we think “volunteer extraordinaire” and “advocate for urban trees”.  Having worked with Dave for many years, I am lucky to be able to add “noble friend” to the long list of extraordinary attributes and gifts he so generously shared.  Dave passed recently, and need I say he will be greatly missed. 

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Why Plant Natives?

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Why Plant Natives?

When we talk to people about plants, they often use “drought tolerant” and “native” interchangeably. (Sometimes we do it too) So why differentiate between them? Isn't drought tolerant enough? Everybody understands the “drought tolerant” part but what’s often overlooked is “native”.

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Why Planting Trees During a Drought Is a GREAT Idea!

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Why Planting Trees During a Drought Is a GREAT Idea!

We here at Our City Forest love talking to local residents, neighbors and random passers-by when we’re serving the communities of the Silicon Valley. We get asked a lot of questions about who we are and what we do. In general these interactions are friendly but sometimes, when the hoses are running and the water buckets are filling we get asked:

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