Botany: the World of Plants

When trees drop leaves in the fall, which is like garbage, that is actually good for the environment. The material of the fallen leaves, came from carbon dioxide. (Trees breathe in carbon dioxide and drink water, but the oxygen from CO₂ an H₂O are not used the same.). More will be detailed later below, see the carbon cycle, cars, and palm trees near the bottom of the page.

Altogether there are more than 290,000 known plant species, with about 250,000 being flowering plants and 15,000 being mosses.

Most of our food comes from angiosperms. Just 6 crops: maize, rice, wheat, potatoes, sweet potatoes, and cassava, yield about 80% of all calories consumed by humans.

The % mass of dry tissue in plants, are about 45% carbon, 45% oxygen (both primarily absorbed as CO₂), 6% H (from water), 1.5% N, 1% K, .5% Ca, .2% Mg, .2% P, and .1% S. This means the CO₂ makes up about 90%.

Plants can also emit hydrocarbons to the atmosphere. Pine trees emit alpha-pinene, citrus trees emit limonene, and various plants emit terpenes, such as isoprene, monoterpenes, and sesquiterpenes. Most of the plants that produce terpenes are conifers (evergreen trees, shrubs such as pine and cypress), plants of the genus Myrtus, and trees and shrubs of the genus Citrus. Plants that emit isoprene include cottonwood, eucalyptus, oak, sweetgum, and white spruce trees. (See more in-depth details further down in the VOCs section.).

The 3 by 2 classification system: C3, C4, and CAM, with vascular and non-vascular plants.

The % is calculated from 293,000. C4 plants were discovered in the 1960s, from studying sugar cane. CAM plants use about 20% of water used by C3 plants. Non-flowering plants make up about 38,106 species, flowering plants 250,000, (totaling 288,106).

C3 is the common method of photosynthesis. C4 photosynthesis evolved in certain plants to conserve water that is lost in the C3 process cycle. So these plants have modified their leaf anatomy to allow the plant stomata to remain closed when fixing carbon, which prevents water loss. So these plants live in hotter and drier environments.

CAM (Crassulacean Acid Metabolism) was 1st discovered in the Crassulaceae family. This pathway also evolved to conserve water, and the process is separated by time. At night, the stomata open and allow CO2 in where it is fixed and store, and at day, photosynthesis occurs while stomata remain closed. So these plants are also suited for hot and arid environments.

Non-vascular plants are predominantly found in moist places, so it is safe to say that there are no non-vascular plants that are C4 or CAM.

The above formula is false, and is what you were all taught in schools. But it is a simplification, because the amount of oxygen in water absorbed does not balance the amount of oxygen gas emitted, which makes people think the rest of the oxygen came from carbon dioxide, which is not the case. A correct version of the formula is.

And on the topic of misconceptions that are false, another 1 is that plants reflect green light. Not in the sense that it only reflects green spectral light, but actually reflects a combination of light that appears green. Plant emit opposite colors from what they absorb, in the color wheel. By color wheel, we mean RGB color wheel for light, and not the RBY color wheel for paint. The RBY color wheels lists red and green as opposite-side colors, but the RGB color wheel lists cyan as the opposite of red. If you look at the opposite of green, you see the purple range, bounded between red and blue. Of course we know the chlorophylls in plants absorb red and blue. And so, their opposite colors, are cyan and yellow. To the extent that blue light and yellow light combines to make visually a green light, then you can think of "light blue" and yellow to make a lighter green.

In photosynthesis, plants, algae, and cyanobacteria, use light to split water using a catalytic Mn₄O₅Ca cluster (previously called Mn₄Ca before 2011), which is embedded in the photosystem II protein complex. Exceptions to this are anoxygenic photosynthetic organisms (e.g., purple sulfur bacteria) which rely on other electron donors like hydrogen sulfide or organic compounds. The Mn₄O₅Ca cluster splits water into O₂, protons, and electrons, and supplies electrons into the electron transport chain. There is no equivalent oxygen-evolving complex in photosystem I, which does not oxidize water. It takes electrons from plastocyanin (or cytochrome C6) and use light energy to boost them to a very high redox potential. Its terminal electron acceptor is ferredoxin, which reduces NADP⁺ to NADPH.

-Photosynthesis generates over 100 billions tons of dry biomass worldwide annually.
-Sunlight powers production of over 3,800 tons of dry biomass every second.
-You need 8 photons to produce a molecule of O₂ (4 in PSII, 4 at PSI) and fix 2 NADPH. But in practice, photoprotective processes and inefficiencies push it to 10-12 photons per O₂.
-It takes 300 chlorophylls to make 1 molecule of O₂ in each oxygen-evolving complex in PSII, or 2500 chlorophylls in both the PSII and PSI antenna systems (thylakoid membranes), depending on antenna size and light-harvesting efficiency.

2H₂O -> O₂ 4H⁺ + 4e^-, E° = -1.23 V (at pH 0), ΔG = -475 kJ/mol. But at pH 7, E° = -1.23 + (.059 * 7) (Nernst equation) = -1.23 +.413 = -.817 V for oxidation potential.

How do plants do what they do, without a brain? Since plants can’t run and frequently get eaten, it serves them well not to have irreplaceable organs. It can lose up to 90% of its body and not be killed.

Plants can sense and respond to light, gravity, sound, temperature, microbes, and chemical signals from other plants.

Electrical and chemical signals identified in plants are homologous to those found in the nervous system of animals. Plants also possess the same neurotransmitters: serotonin, dopamine, and glutamate (but their roles remain unclear, as of 2006).

Since the early ‘80s, it’s been known that when an insect chew on plant leaves, the plant leaves can emit a chemical that signal other leaves to mount a defense, and that includes making the leaves less desirable. For example, when antelopes browse acacia trees, the leaves produce tannin, which makes them unappetizing and difficult to digest.

Plants can also exhibit a defense against attackers by proxy: when corn and lima beans are being eaten by caterpillars, they emit a chemical distress call, where parasitic wasps respond to the scent, fly to the plant, and then attack the caterpillars.

While brains are considered as a whole function centralized command centers for humans and most animals, within the brain however, there doesn’t appear to be a command-post. Rather, 1 finds a leaderless network. So the roots of plants can be thought of as a brain in its entirety.

Plants make decisions based entirely on the net flow of auxin and other chemical signals. Experiences such as stress, can alter the molecular wrapping around the chromosomes, which, in turn, determines which genes will be silences and expressed.

Trees have roots which can send communication to other members of the same species and related, such that the forest behaves like a network. They communicate by sending chemical and hormonal signals to each other via the mycelium. When 1 tree is shaded or leafless, other trees send more carbon. This is contrary to the belief that trees competed with each other for carbon, sunlight, water, and nutrients, but experiments show trees were also cooperators.

What happens if you take an Arctic plant and put it in the warm, equatorial regions? Will it be happy?

That will cause plants to lose a lot of water. Some plants like the coniferous tree, will survive, but others not. However, the bigger issue, is putting a plant in the warm area, will expose plants to different kinds of bacteria and fungi.

Some cacti don’t mind as some cacti exist in rainfall areas. But the generalization is, plants will rot.

What happens if you give plants 24-hour sunlight? Some will keep growing, but not produce flowers or fruit.

Most plants prefer slightly acidic soil. At pH 8, plants can absorb calcium, but iron is almost unavailable. At pH 5 or lower, toxic Al³⁺ ions become more soluble and are absorbed by roots, stunting plant growth and preventing the uptake of calcium. The major mechanism of aluminum resistance is to secrete organic acids (such as malic acid and citric acid) by roots, which bind to free aluminum ions. See more in-depth details further down.

For flowers, perennials come back every year, annuals only last 1 year, or annuals poorly come back in following years. The downfall is, annuals don’t mind being grown in a container, whereas perennials do.

Should you plant annual flowers or perennial flowers? 1 lesser-obvious factor are birds, which may come and eat up the seeds. In an area like Chicago, where robins, pigeons, and some cardinal birds dominate, only robins will eat up the seeds of annual flowers, and not the seeds of perennial flowers or grass. Even after growing some annual flower seeds indoors, and they grew into a thin green plant over an inch tall, the robins still come and tear the plants up.

Mulch is a general term for many organic and inorganic substances used in the garden. Compost is an organic substance from the decomposition of plant materials. It is always the 1st choice for soil nutrition and amendment.

Pollen is the plant equivalent of sperm. In angiosperms, pollination is the transfer of pollen from an anther to a stigma. About 65% of all flowering plants species require insects for pollination, about 20% of angiosperm species are wind-pollinated, and about 12% of flowering plants, as well as most conifers, are wind-pollinated (flowering plants are a type of angiosperm, and angiosperms are a division of seed-producing plants). Bees are attracted to primarily yellow and blue flowers, while red appears dull to them.

Not all flowers produce pollen, but all trees produce pollen. In trees, pollen is the male gametophyte of seed plants. It is produced in the male reproductive structures of the tree, such as the stamens or anthers. Pollen is released into the air or transferred by pollinators like bees, insects, or wind to reach the female reproductive structures of the tree, such as the pistils or ovaries, for fertilization. This fertilization process leads to the formation of seeds and the continuation of the tree's life cycle.

However, in dioecious plants, only the male produces pollen. In holly trees for example, the male trees produce small clusters of flowers while female holly trees produce characteristic red berries. In ginkgo trees, the males produce pollen cones while females produce seeds. About 65% of gymnosperms are dioecious, and almost all conifers are monoecious.

Some flowers have been bred or cultivated to produce little or no pollen, such as petunias, begonia, and impatiens.

Additionally, some plants have separate male and female flowers, where only the male plant has flowers that produce pollen (such as asparagus, kiwi, hop, willow, and cannabis).

Fruits primarily pollinated by bees include apples, blackberries, blueberries, cherries, cranberries, grapefruits, lemons, oranges, raspberries, and strawberries.
Vegetables primarily pollinated by bees include cucumbers, bell peppers and chili peppers, tomatoes (though are also self-pollinating), zucchini and summer squash.

Fruits primarily pollinated by birds include persimmons (by orioles) and passion fruits (by hummingbirds).
Vegetables primarily pollinated by birds include pumpkins.

Fruits primarily pollinated by bats include bananas, durian, and mangoes.
Vegetables primarily pollinated by bats include agave and cacti.

While butterflies pollinate some vegetables (such as pumpkins and cucumbers), they are not the primary pollinator for them. But in the world of flowers, there are flowers primarily pollinated by butterflies (such as butterfly bush, milkweed (Asclepsias), and lantana flowers), flowers primarily pollinated by bees (such as sunflowers, lavender, goldenrods, and asters), as well as flowers mainly pollinated by both butterflies and bees (such as zinnias, coneflower, verbena flowers, larkspur (Delphinium), and marigolds).

According to the U.S. Forest Service, almost 80% of crop plants grown around the world require pollination by animals, meaning humans couldn’t survive without pollinators. Unfortunately, climate change decreases the population of certain pollinators such as bees and butterflies.

The only known frugivorous frog, is the Izecksohn's Brazilian treefrog (Xenohyla truncata). According to an article published on science.org on May 1, 2023 showed this Brazilian treefrog may be the 1st pollinating amphibian known to science.

Legal advice: in the U.S., it is generally more legal to kill yellowjackets than it is to kill honeybees. Many bees are protected by conservation laws, while yellowjackets are considered more as pests. German yellowjackets are much more aggressive, but aren't found in North America.

It is possible to be poisoned to death, from drinking the milk of cows, of cows that have ate poisonous plants. An example is the white snakeroot, in the Americas in the 1800s, which contains the toxin tremetol. This is how Abraham Lincoln’s mother died. It is also possible to have irritation and blistering of the skin, just by standing underneath a poisonous tree when it rains, such is the manchineel tree, which is 1 of the most toxic trees in the world. The most poisonous shrub in Australia area is gympie-gympie, in which their trichomes (needles) can be inhaled just from standing next to them.

Chemical/crystal examples: calcium oxalate (found in the cells of dieffenbachia, found in dumbcane, found in daffodils), furanocoumarins (found in the sap of giant hogweed, it can penetrate skin cells, into the nuclei alongside the cells’ DNA, as well as poison nearby plants through the soil), phorbol (found in the machineel tree, they mimic the action of diacylglycerol, which is a fatty molecule your body uses to activate PKC (protein kinase c), which regulates things like cell growth and metabolic activity).
Alkaloid examples: lycorine (found in daffodils), aconitine (found in aconite aka devil’s helmet and monkshood), coniine (found in hemlock, which poisoned Socrates), atropine and solanine (both found in deadly nightshade (belladonna), where 10-20 berries can kill an adult), hyoscyamine and scopolamine (both found in both jimsonweed and belladonna), and physostigmine (a parasympathomimetic alkaloid found in Calabar beans and the fruit of manchineel trees).
Cardiac glycosides examples: oleandrin (found in oleander, which also contains nerine (interferes with Na and K pump in heart muscle cells). Digitoxin (found in foxgloves), cerberin (found in pong pong aka suicide tree, and sea mango), convallotoxin (found in lily of the valley, which affects the heart, and also contains saponins).
Neurotoxin examples: grayanotoxins (found in pollen and nectar of rhododendron). Grayanotoxin I is acetylandromedo, which slows both opening and closing of sodium channels in nerves.
DNA alkylating agent examples: cycasin (found in sago palm, once broken down, produces methylazpxymethanol).
Ribosome-inactivating protein examples: viscumin (found in European mistletoes, 2.4 mg/kg can kill a mammal), ricin, abrin (found in rosary peas, 1/10th of a mg can kill an adult).
Saponins: sapogenin (found in manchineel tree), cyclamine (a triterpenoid saponin, found in cyclamen), and in general, found in lily of the valley.

Urushiol is an oily resin produced by poison ivy. The leaves have to be damaged in order to get skin contact with it. They are harmful to humans and hamsters, but no effect to deer, birds, and insects.
Animals susceptible to pyrrolizidine alkaloids (which do liver damage) include rats, cattle, horses, and chickens, but animals resistant to them include guinea pigs, rabbits, gerbils, hamsters, sheep, and Japanese quail.

It is possible to be allergic to berries (strawberries, raspberries, blackberries, and blueberries) while not allergic to cherries, as cherries are not a berry. It is also possible to be allergic to honeydew, but not cantaloupe. As well as raw apples, but not cooked apples.

Trees and grass allergies: 1 of the most common types of pollen that may cause sneezing and sniffles in the spring is tree pollen, which can reach peak levels from March through May, while grass pollen starts in May and ends in June. The Centers for Disease Control and Prevention noted that pollen can trigger different reactions in people, like symptoms of allergic rhinitis or hay fever, which affects about 60 million people in the U.S. annually. According to the Asthma and Allergy Foundation of America, more than 80 million Americans deal with itchy eyes, runny nose and other symptoms of seasonal allergies.

3 types of pollen can cause seasonal allergies. Tree pollen pops up in early spring, grasses pollinate, and weeds appear late in the summer and early fall. The most common tree pollens causing allergies include birch, cedar, cottonwood, maple, elm, oak, and walnut, according to the Asthma and Allergy Foundation of America. Grasses causing these symptoms include Bermuda, Johnson, rye, and Kentucky bluegrass.

The average car produces more pounds of carbon dioxide than it weighs, in a year. The average car produces over 11,000 lbs of CO₂ in a year (calculating at a 3,500 lb car, running 12,000 miles/year, and 1 gallon giving off 20 miles). The average palm tree in southern Florida, only absorbs about 5 lbs of CO₂/year. Compared to other trees such as oaks, mahogany, pines, and cedars, they can sequester more than 3,000 pounds of CO₂ in their lifetime.

Note: the oxygen released from plants does not come from carbon dioxide, it comes from water.

For those that live in deciduous places, if at the end of fall you bag up all your fallen leaves and put them in the garbage, that can just go to a wasted landfill. Recycling leaves (including shredding them) make good compost or and mulch. Fallen leaves contain essential nutrients that help with soil rejuvenation. Shredded leaf litter as mulch, helps suppress weeds, regulate soil temperature, conserve moisture, reduce soil erosion, and decompose over time to provide nutrients. According to the University of Delaware's College of Agriculture and Natural Resources, estimates 2 tons of leaves will fall on 1 acre of temperate forest each fall, beginning a cycle in which those nutrients are taken up by trees to produce a new crop of leaves the following spring.

Fruits	pH	Vegetables	pH
Apple	5.5-6.5	Asparagus	6.0-8.0
Banana	5.5-6.5	Beans	6.0-7.0
Blackberry	5.0-6.0	Beets	6.5-8.0
Blueberry, high bush	4.5-5.5	Broccoli	6.0-7.0
Cantaloupe	6.0-7.5	Cabbage	6.0-7.5
Cherry	6.5-8.0	Carrots	5.5-7.0
Grapes	5.5-7.0	Cauliflower	5.5-7.5
Nectarine/Peach	6.0-6.8	Corn	5.5-7.5
Pear	6.5-7.5	Cucumber	5.5-7.0
Plum	6.5-8.5	Eggplants	5.5-6.5
Raspberry, black	5.5-7.0	Lettuce	6.0-7.0
Raspberry, red	6.0-7.5	Onions	6.0-7.0
Strawberry	5.5-6.5	Peas	6.0-7.5
Tomato	5.5-7.5	Pepper	5.5-7.0
Watermelon	6.0-7.0	Potatoes	4.8-6.5
		Sweet potatoes	5.2-6.0
		Radish	6.0-7.0
		Rhubarb	5.5-7.0
		Spinach	6.0-7.5
		Squash	6.0-7.0
		Turnip	5.5-7.0

Why is the most acidic soil requirements required, and the most basic soil requirements, required?

It has to do with where they originated from. Blueberries originated in colder, northern latitudes. The potatoes originated in the colder Andes Mountains. The basic pH tend to originated in areas with a lot of limestone.

Some vocabulary concepts to look at are marcescence and abcission: the withering and dropping of tree leaves, and inflorescence, where 2 flower heads stem from the same branch.

1. Juliet Rose: which was bred by English rose breeder David Austin, is a rare and expensive flower. In 2006, a bouquet of Juliet roses was sold for $15.8 million at an auction in Japan.

2. Shenzhen Nongke Orchid: which was created by Chinese scientists through a process of cell fusion, is a rare and valuable flower. In 2005, a Shenzhen Nongke orchid sold for $200,000 at an auction in China.

3. Eustoma Grandiflorum: which is also known as the Lisianthus or Prairie Gentian, is a popular flower for weddings and other special occasions. In 2015, a bouquet of Eustoma Grandiflorum flowers was sold for $10,000 in the U.S.

4. Gold of Kinabalu Orchid: which is native to Malaysia, is a rare and beautiful flower that has been sold for thousands of dollars. In 2005, a Gold of Kinabalu orchid sold for $5,000 at an orchid show in Malaysia.

5. Kadupul Flower: which is native to Sri Lanka, is considered 1 of the most expensive flowers in the world. It is so rare that it cannot be bought or sold at a store, as it only blooms at night and wilts by dawn. However, in 2013, a Kadupul flower was sold to a private collector in Hawaii for $3,000.

In the U.S., Americans eat more pounds of strawberries than raspberries and cherries. In 2020, the U.S. produced about 3.1 billion pounds of strawberries, 271 million pounds of raspberries, and 339 million pounds of sweet cherries while 71 million pounds of tart cherries.

The most consumed fruit in the U.S. according to the USDA are 1. bananas 2. apples 3. oranges then 4. grapes.

The most consumed vegetables in the U.S. according to the USDA are 1. potatoes 2. tomatoes 3. sweet corn 4. onions 5. green beans 6. carrots 7. lettuce 8. bell peppers 9. cucumbers then 10. broccoli.

As of Dec. 2019, Apples are a $2.5 billion a year business in Washington, which grows about 60% of the nation's supply. The top varieties are Gala (23%), Red Delicious (20%) and Fuji (13%). About 50,000 people pick some 12 billion apples by hand each fall. The fruit is exported to 60 countries. The next states for apple production are New York, then Michigan, then Pennsylvania, then California, then Virginia.

Florida used to produce >70% of the nation's citrus industry. In 2021, Florida's citrus industry generated almost $7 billion, and employed over 32,000 jobs. It produced 79% of total U.S. citrus in 2002, down to 36% in 2022. In 2023, California made 79%, Florida 17%, with Texas and Arizona combined to make the remaining 4%.

This is mainly due to citrus greening, which robs trees of nutrition. When a tree is hit with citrus greening, it drops its fruits early. Citrus greening was 1st detected in 2005 in Florida, and thought to originate from an Asian citrus psyllid bug. In Brazil, which is the world's largest orange juice producer, had 24% of citrus trees infected in 2022, to 38% in 2023.

Fluorescence: in 2008 scientists discovered when a banana becomes ripe, it glows bright indigo under a black light. Some insects, as well as birds, see into the ultraviolet, and because they are tetrachromats, they can use this information to tell when a banana is ready to eat. The glow is the result of a chemical created as the green chlorophyll in the peel breaks down.

There is no fiber in meat, dairy, or sugar. Refined or “white” foods, such as white bread, white rice, and pastries, have had all or most of their fiber removed.

Fruit	Vegetable
Raspberry 6.5 g	Avocado 6.7 g
Blackberry 5.3 g	Kale 4.1 g
Banana 2.6 g	Brussel sprout 3.8 g
Apple, blueberry 2.4 g	Carrot 2.8 g
Cherry 2.1 g	Broccoli 2.4 g
Strawberry, orange 2 g	Spinach, red onion 2.2 g
Tomato 1.2 g
Grape <1 g	Cucumber <1 g

There are different types of fiber. Soluble fiber partially dissolves in water, and resembles jelly. Insoluble fiber is another kind of fiber that passes through your digestive system basically unchanged. Different kinds of fiber protect against different kinds of diseases.

2 anti-cancer foods are fiber and anti-oxidants. Fiber, because it helps remove toxins in the intestines. They remove things quicker in the colon compared to others. Fiber does not go to blood vessels.

In April 2020, researchers reported having genetically engineered tobacco plants (Nicotiana tabacum) glow much brighter than previously possible by inserting genes of the bioluminescent mushroom Neonothopanus nambi (1st discovered in Paraguay in Dec. 1879). The glow is self-sustained, and works by converting the plants caffeic acid into a substrate compound called luciferin and, unlike for bacterial bioluminescence genes used earlier, this glows much brighter. The genetic and molecular mechanisms underlying this mushrooms bioluminescence were published in 2019, the 1st to be elucidated for a fungus. The glow is caused by the activity of the enzyme luciferase, which oxidizes a fluorescent compound known as luciferin to give off light. It glows a green color.

Prior to inserting the mushrooms genes into tobacco plants, they published in late Nov. 2018 to testing it on yeasts 1st, led by Ilia Yampolsky at the Institute of Bioorganic Chemistry of the Russian Academy of Sciences in Moscow. The glowing mechanism of the mushroom, was published in May 2017.

Their April 2020 explanation for this green light emitted is as follows: their light emission centers on an organic molecule that is also needed in plants for making cell walls. This molecule, called caffeic acid, produces light through a metabolic cycle involving 4 enzymes. 2 enzymes convert the caffeic acid into a luminescent precursor, which is then oxidized by a 3rd enzyme to produce a photon. The last enzyme converts the oxidized molecule back to caffeic acid to start the cycle again. In plants, caffeic acid is a building block of lignin, which helps provide mechanical strength to the cell walls. It is thus part of the lignocellulose biomass of plants, which is the most abundant renewable resource on Earth.

2 things produced by plants: organic acids from roots, and releasing volatile organic compounds.

Organic acids have been known to alleviate Al³⁺ toxicity in vitro for many years (1972), but the secretion of organic acids from the roots as an Al³⁺ tolerance mechanism was 1st suggested by Kitagawa and others in 1986. Al³⁺ toxicity has been recognized as a major factor limiting crop productivity on acid soil, which comprises about 40% of the arable land in the world (as of 1978). Al³⁺ inhibits root growth by altering the root structure and thereby reducing its absorption capacity for water and nutrients. Organic acids form stable complex with Al³⁺, thereby detoxifying it.

Some organic acids include citric, oxalic, malic, tartaric, salicylic, malonic, succinic, and maleic acids. All of them are considered to be low molecular weight organic acids (ranging from 90 to 150), whereas high-molecular weight organic acids include the humic substances, such as humic acid and fulvic acid.

Plants that secrete 1 organic acid:
Malic acid from wheat. Citric acid in snapbean, maize, and the Moluccan albizia tree. Oxalic acid from roots of buckwheat and taro.

Plants that secrete 2 organic acids:
Rapeseed, oats, and radish secrete both malic and citric acids.

Amount of organic acids in soil.
The concentration of Al³⁺ in acid soil solutions ranges from 10 to 100 µM. According to 1 2017 study, across a broad range of ecosystems, the concentration of organic acids in soil solution typically ranges from 0 to 50 µM for di/tricarboxylic acids (oxalic, malonic, malic, succinic, tartaric and citric acid) and from 0 to 1 mM for monocarboxylic acids (formic, acetic, propionic, butyric, valeric and lactic acid).

The efficiency of organic acids for soil biological processes follows a decreasing order from tricarboxylic low molecular weight organic acids (citric and tartaric acids), dicarboxylic low molecular weight organic acids (maleic and fumaric acids) and the monocarboxylic low molecular weight organic acids (oxalic and acetic acids) as the least.

The Al³⁺-detoxifying capacity of organic acids depends on the stability constants of the Al³⁺-organic acid complexes. For example, equimolar citric acid can detoxify Al³⁺, but 3 times more oxalic acid and 6-8 times more malic acid than Al³⁺ are required to detoxify Al³⁺ (from studies concluded in 2000). The different Al³⁺-detoxifying capacity of organic acids results from their structural configurations, specifically the relative positions on the main carbon chain of OH and COOH groups. The most effective detoxifying acids have either 2 pairs of OH/COOH attached to 2 adjacent carbons (citric and tartaric) or 2 COOHs directly connected (oxalic), forming stable 5- or 6-bond ring structures with Al³⁺.

This role could be organic acid specific, for example, a concentration of malic and oxalic acid at 50 µM could not detoxify Al³⁺ in soybean and cowpea soil, whereas fulvic acid was extremely effective at 65 mg/L (Suthipradit et al., 1990). In addition, the tri-carboxylic and the di-carboxylic organic acids have been reported to be more effective in the detoxification of aluminum (Fischer et al., 2010). This suggests that the efficiency of the detoxification of Al³⁺ in soil by organic acids is dependent on the concentration and valence of the carboxyl group of the organic acid in solution.

How organic acids are made.
Organic acids are synthesized in plants as a result of the incomplete oxidation of photosynthetic products and represent the stored pools of fixed carbon accumulated due to different transient times of conversion of carbon compounds in metabolic pathways. When redox level in the cell increases, e.g., in conditions of active photosynthesis, the tricarboxylic acid (TCA) cycle in mitochondria is transformed to a partial cycle supplying citrate for the synthesis of 2-oxoglutarate and glutamate (citrate valve), while malate is accumulated and participates in the redox balance in different cell compartments (via malate valve). This results in malate and citrate frequently being the most accumulated acids in plants. However, the intensity of reactions linked to the conversion of these compounds can cause preferential accumulation of other organic acids, e.g., fumarate or isocitrate, in higher concentrations than malate and citrate. The secondary reactions, associated with the central metabolic pathways, in particularly with the TCA cycle, result in accumulation of other organic acids that are derived from the intermediates of the cycle. They form the additional pools of fixed carbon and stabilize the tricarboxylic acid cycle. Malonate is accumulated at high concentrations in legume plants.

-Malic acid was 1st isolated from apple juice by chemist Carl Wilhelm Scheele in 1785.
-Citric acid was isolated 1 year earlier, by same chemist, who crystallized it from lemon juice.

More than 1700 VOCs have been identified from angiosperms and gymnosperms, from a total of 90 families and 38 orders. Based on their biosynthetic origin, VOCs can be classified into 3 major groups, in order from largest to smallest: terpenoids, phenylpropanoids/benzenoids, and fatty acid derivatives. Terpenoids encompass over 550 compounds. Phenylpropanoids and benzenoids are derived from the aromatic amino acid phenylalanine, which is synthesized via 2 alternative branched pathways that connect central carbon metabolism to phenylalanine. Fatty acid derivatives such as (Z)-3-hexenol, 2-ketones and methyl jasmonate, derive from C₁₈ unsaturated fatty acids, linoleic acids, or linolenic acids. Biosynthesis of these compounds depends on the plastidic pool of acetyl-CoA generated from pyruvate, the last product of glycolysis.

-Pollinator attraction.
-Plant–herbivore interactions.
-Plant–plant interactions.
-Protection from pathogens.

There are also bacteria-specific VOCs emitted by plants with a diagnostic purpose, triggering defense signaling pathways and acting as direct inhibitors of bacterial growth, therefore making plants more resistant to pathogen invasion, such as with the Arabidopsis thaliana flowers, emitting the sesquiterpene (E)-ß-caryophyllene.

In the field of analyzing VOCs, GC-MS is considered the most common and powerful analytical technique due to the complexity of VOCs, as well as with proton transfer reaction mass spectrometry (PTR-MS).

VOC examples, by plant:
For strawberries, release hexanoic acid, octanoic acid, methyl butanoate, cinnamyl acetate, ethyl butyrate, and others.

VOC examples, by compound:
-Isoprene is mainly produced by species of trees (oaks, poplars, eucalyptus, and some legumes), and shrubs. In deciduous forests, makes up about 80% of hydrocarbon emission.
-A type of diterpene, such as taxanes, are produced from plants of the genus Taxus, which are yew trees.

Some leaves contain compounds that inhibit the growth of other plants. Black walnut is perhaps the most notorious example, as a toxic chemical in its leaves called juglone adversely affects and sometimes even kills susceptible plants like Asiatic lilies, baptisia, columbines, peonies, hydrangeas, lilacs, petunias, apples, asparagus, cabbage, eggplant, peppers, tomatoes, and potatoes.

Plant growth regulators are broadly utilized in fruit crops harvests to advance vegetative development, blossoming, and fruit improvement. Plant development controllers have been found to indirectly affect sprouting by lessening the vegetative turn of events.

The 1st plant growth regulator was chlormequat, discovered by professor Tolbert at Michigan State University in the 1950s which is a synthetic plant growth regulator antagonist to gibberellic acid. The chlormequat has been shown in studies to effectively reduce the growth of potato stems, leaves, and thicken the stem of mung bean by controlling vein growth and lodging, as well as additional root development and increase chlorophyll concentration.

Chlormequat is an inhibitor of gibberellin biosynthesis that inhibits cell elongation, resulting in thicker stalks, which are sturdier, facilitating harvesting of cereal crops.

The discovery of plant growth regulators after chlormequat, include gibberellic acid (GA) and indole-3-acetic acid (IAA). Gibberellic acid was 1st isolated from the fungus Gibberella fujikuroi, and its effects include promoting stem elongation and seed germination. Indole-3-acetic acid, a type of auxin, plays a crucial role in various aspects of plant growth and development, including cell elongation, root development, and apical dominance.

Note that some things have already covered flowers in this page, such as pollination and gardening.

Some flowers of the same species can be annuals or perennials, but majority are cases where they are only annuals in colder climate such as North America. So, there is some ambiguousness here: "most marigolds" does not mean most marigolds produce pollen and nectar, but most means most marigolds are annuals.

Orchidaceae is the largest family of flowering plants, followed by Asteraceae. It contains about 28,000 species across 763 genera, while Asteraceae contains about 24,700 species across 1,623 genera, as of 2016.

Botanists are set to vote at Madrid’s International Botanical Congress on renaming plant species that contain racial slurs and other such offensive names, Nature reported.

The International Botanical Congress, which meets every 6 to 7 years to weigh on rules for naming plants, fungi and algae, will vote on 2 proposals revolving around culturally sensitive designations, the weekly scientific journal reported.

1 proposal aims to remove all species names based on the word “caffra” and its derivatives — which are ethnic slurs against southern African Blacks — and substitute the word “afr” and other derivatives in their place. This proposal would affect some 218 species. The 2nd proposal would establish a committee to deal with offensive names. The amendments would require a supermajority of 60% of attendees approving it in order to pass.

The proposals have their opponents. “It’s very unfortunate that many of these names are offensive,” Alina Freire-Fierro, a Technical University of Cotopaxi botanist, told the journal. “To change the names that have already been published would cause so much confusion.” Gideon Smith, a plant taxonomist at Nelson Mandela University (NMU) in South Africa and 1 of those behind the “caffra” proposal, said “There is resistance against these proposals, the fear of throwing plant nomenclature into chaos,” according to Nature. “I cannot think of any simpler way to get rid of this racial slur.”

Species named after colonial figures like Cecil Rhodes, a colonial official, and George Hibbert, a slave trader, have also come under fire, Nature noted. “There should be a way of dealing with cases like Hibbert,” Kevin Thiele, an Australia National University plant taxonomist, told the journal. Thiele emphasized that the renaming of species should only be limited to “sufficiently egregious” historical figures.

Lennard Gillman, a former New Zealand evolutionary biogeographer and consultant, told Nature that future congresses should consider whether existing plant names should be replaced by the names used by indigenous peoples. “Change often happens incrementally.”

Microbes hidden within tree bark can absorb methane from the atmosphere, according to a study published 24 July in Nature. An international team of researchers led by the University of Birmingham has shown for the 1st time that microbes living in bark or in the wood itself are removing atmospheric methane on a scale equal to or above that of soil. They calculate that this newly discovered process makes trees 10% more beneficial for climate overall than previously thought.

Methane is responsible for around 30% of global warming since pre-industrial times and emissions are currently rising faster than at any point since records began in the 1980s. The researchers investigated upland tropical, temperate and boreal forest trees. Specifically, they took measurements spanning tropical forests in the Amazon and Panama; temperate broadleaf trees in Wytham Woods, in Oxfordshire, UK; and boreal coniferous forest in Sweden. The methane absorption was strongest in the tropical forests, probably because microbes thrive in the warm wet conditions found there. On average, the newly discovered methane absorption adds around 10% to the climate benefit that temperate and tropical trees provide.

The tree shape analysis also found that if all the bark of all the trees of the world were laid out flat, the area would be equal to the Earth's land surface.

from red grapes
Domaine de la Romanée-Conti (from Pinot Noir grapes)
Screaming Eagle (from Cabernet Sauvignon grapes)
Domaine Leroy Musigny Grand Cru (from Pinot Noir grapes)

from dark blue grapes
Château Petrus (from Merlot grapes)
Penfolds Grange (from Syrah grapes)

from green grapes (white wines)
Domaine de la Romanée-Conti Montrachet (Chardonnay)
Domaine Leflaive Montrachet (Chardonnay)
Egon Müller Scharzhofberger Riesling Trockenbeerenauslese (Riesling)
Domaine Coche-Dury Corton-Charlemagne (Chardonnay)
Cheateau d'Yquem (Semillon)

Note that the wine industry tends to only recognize 2 colors in grapes.
According to artwinepreserver.com, they only listed red and green colored grapes, no blue.
According to habershamwinery.com, "Wine grapes come in two colors, black and green. By black, we mean red."

Note that most grapes are used either for grocery stores (table grapes), or to make wine (wine grapes). The overlap appears to be very small. Muscat seems to be the most common grape variety used for both. There are also wines made of Thompson Seedless grapes.

European wines tend to be classified by region (e.g. Bordeaux, Rioja, Chianti), while non-European wines are most often classified by grape (e.g. Pinot Noir, Merlot). But region-name company-name is the most common.

In Aug. 2007, a consortium of researchers, announced the sequencing of the genome of Pinot noir. It is the 1st fruit crop to be sequenced, and only the 4th flowering plant.

1 reason is that many red wines, being rich in tannin, mature slower and have their peak later. Thus, they become more expensive simply because they require more attention and storage to bring to the table at the right time. You won't usually find 10 year old white wines, while 10 year old reds is not unusual at all.

Lambrusco: Lambrusco is a red sparkling wine from Italy known for its fruity and sweet characteristics. Some varieties of Lambrusco can have flavors reminiscent of grape juice, with a balance of sweetness and acidity.

Moscato d'Asti: Moscato d'Asti is a sweet and aromatic white wine originating from the Asti region of Italy. It is made from the Muscat grape and often has intense grape flavors and a characteristic grape juice-like sweetness.