A field of tomatoes wilts. A stand of tanoak trees dies. A forest of bay laurels and manzanita withers. An orchard of citrus yellows and decays. A wildland restoration project crumbles into dust. Potatoes turn rancid and spongy. These are the calling cards of Phytophthora, the destroyers of plants
Viewing entries tagged
With spring and summer come farmers markets and a wide variety of fruits and vegetables. In the next two months, berries of a ton of different varieties come into season including, strawberries, raspberries, blackberries and blueberries. Well, I say berries but really only one of the berries mentioned is actually a berry. Guess which one? I’ll wait. As the narrator of a blog piece about botanical fruit varieties I have infinite time.
Welcome back to Everything You Wanted to Know About Plants. Last time I talked to you about how palms are sneaky devils that trick you with their woody wiles into believing that they are trees like any self-respecting pine, oak or maple
So now that we’ve sprinted through approximately 480 million years of evolution, going from Charophyte algae to bryophyte moss to primitive vascular Cooksonia to the first forests it’s time stop, breathe, and look around at the plants in our lives.
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.
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.
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).
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).
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.
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.