www.RogerWendell.com
Roger J. Wendell
Defending 3.8 Billion Years of Organic Evolution^SM

Plants, Botany, and Plant Biology

The inside lobby of an Oklahoma City hotel

I've always loved plants and growing things. I started small gardens and miniture "nature centers" during my pre-teens and have carried that love with me through my 50s when I decided to create this page. My guess, too, is that more gardens and plants around the world would add to Biodiversity, and slow Climate Change but that's another story... - Roger J. Wendell

Click Here for my YouTube video of pollen being blown off an Austrian Pine...

Click Here for my page about biodiversity...

Click Here for my page about animals...

Click Here for my page about insects...

Click Here for my page on Evolution...

Botanical Disciplines and The Plant Kingdom

Drawn by me at about age 9

"The science of botany is divided into various disciplines, each having its specialists, subject limitations, and technical vocabulary. Among them, cytology (Greek: kytos, "container") is the detailed study of cells. Study of the form and structure of plants is the work of morphologists (Greek: morphe, "form"). By virtue of their practical relationships with plants, gardeners are more familiar with morphology than with cytology. Plant anatomy deals with their intimate cellular structure as best seen with microscopes. Taxonomy deals with the scientific classification of plants into large and progressively smaller subgroups. Genetics is concerned about inheritance of characteristics from generation to generation. And physiology reveals some of the mysteries of how plants function."   "There are close to 400,000 recognizably different kinds of plants, or species, in the world today. One-third of all plants do not have the familiar roots, stems, and leaves. About 150,000 plant species never produce flowers, and almost that same number do not grow from seeds, but from tiny spores. The vast majority of plants manufacture their own food supplies by a process called photosynthesis. Most plants spend a lifetime anchored in one place, yet a few simple, one-celled plantlike organisms are capable of swimming to different locations in the waters they inhabit."   - Brian Capon in his book, Botany For Gardeners (An Introduction to the Science of Plants), Fourth Edition, p. 13

(Click on any this page's "thumbnail" images for a larger view)

Grand Canyon flowers:
These are from my April, 2006 backpacking trip with Doug and his son Bobby.

Amazonia:

In January, 2006 I took a trip through Ecuador
to do a little climbing and hiking around...

Rapid Plant Movement

Rapid Plant Movement This strange little plant folds up anywhere along the leaf where you touch it!! After a few minutes it unfurls itself and returns to normal. In this particular photo I tried to capture just half of the leaf structure folding up. Either way, it didn't appear that the plant was preparing to "eat" anything (in a way similar to our own Venus Flytrap) - its reaction to touch seems to be some defensive mechanism. I believe this species may be related to Mimosa pudica ("Sensitive Plant") but am not sure...

Texas:

In early May, 2006 I took a business trip to Bandera, Texas that included some spare time around the San Antonio airport area and the Alamo. Texas is much warmer than my home state of Colorado so I was fascinated at the variety of green and flowering plants at a time when there was still snow on the ground in my backyard at home!

Bandera	Bandera	Mayan Ranch at Bandera	Bandera	Bandera
In the town of Bandera...	The Alamo	The Alamo	The Alamo	The Alamo

Gardens

"...it has proven worthwhile for communities to make a public commitment to providing land, horticultural training, soil and compost, and other means of support to enable people who want to garden to do so. Whether people are motivated by the myth of self-reliance, the fear of a cataclysmic event, or simply the wish to make something ugly into something beautiful, society should permit them to stand in humble repose on their own tiny plots of land and to make what magic they can of it. Doing so affords them the opportunity to come together in community to grow plants and to experience for themselves the pulse of the seasons marked by the productions of the earth"

- Mark Winne
Closing the Food Gap (Resetting the Table in the Land of Plenty), p. 45

Seeds

Seeds have always fascinated me as well. Sometimes I see them twirling to the ground like small helicopters off a Maple tree while at other times I see them slowly drifting through the breeze like little ephemeral puffs of cotton off a dandelion, milkweed, or cottonwood tree. However, I think July, 2010 was the first time I ever had a seed burrow into my skin! I don't know what plants these seeds are from (photo at left) but they easily went through my socks while hiking near Red Rock Amphitheatre west of Denver. After removing my socks I actually had one that had burrowed into my skin. And, just like a fish hook, refused to reverse its course? Despite the small amount of paint I remained fascinated by the hardened, barbed tip head of this particular seed. And, when a little moisture hit its "tail" the whole thing start to twist and bend - a "burrowing" action to help find its way into the ground I'm sure!

Click Here for my notes on Composting (on my Recycling page)...

Orchids

Bird Head Orchid

"Orchids can be fickle and fascinating plants, and scientists are really only beginning to understand them. Some remain dormant underground for years, presumed dead by those looking for them. Some bloom for only one day each year. And all germinate from seeds as small as dust."   "With an estimate of at least 25,000 species in existence, and new species being discovered regularly, orchids are believed to be the world's most diverse family of flowering plants. They outnumber all mammals, reptiles and birds combined. And scientists estimate that they account for about 10% of all flowering plant life on Earth."   "But, that impressive quantity and diversity have made ensuring their future a costly challenge. Of the 200-odd species of orchids native to North America, more than half are threatened or endangered ins some part of their range."   - text by Jenny Rogers Nature Conservancy Magazine (Winter 2020) Secret Garden (Unearthing the mysteries of orchids.), p. 46

Plant Evolution
From Lee Billings' Five Billion Years of Solitude
(The Search For Life Among The Stars)

"Two evolutionary innovations spurred the colonization of land, each involving the harvest and transport of water. Land plants 'vascularized,' developing roots to draw water and nutrients from the earth, and they also began building their bodies from lignin, a durable carbon-rich macromolecule strong enough to bear water's heavy weight. The resulting vascular, lignin-rich plants propagated across the continents. They doubled the planet's photosynthetic productivity and dramatically altered the planet's carbon cycle. Once again, life and its environment were shaping each other in a powerful, world-changing feedback loop." p. 131   "A lucky few anaerobes, by dint of mutation and natural selection, adapted to tolerate the newly oxygenated atmosphere and ocean. Some of these new breeds of aerobic prokaryotes, in fact, took revenge on their conquerors by engulfing the cyanobacteria into their bodies as cellular slaves, making oxygenic photosynthesis their own. This process, called endosymbiosis, was what gave rise to the first eukaroyotes, cells with centralized nuclei and specialized cellular structures. Modern plants are green because their cells contain chlorophyll-filled 'chloroplasts' - structures that are scarcely distinguishable from cyanobacteria. The cells of modern plants and animals alike also contain enclosed structures called mitochondria, which ware the cellular components that allow all eukaryotes to draw metabolic energy from oxygen - that is, to breathe. Chloroplasts and mitochondria each carry DNA independent of their host organism, confirming that both are captive descendants of prokaryotes incorporated into eukaryotic cells sometime in the latter half of the Proterozoic." p. 143

Fossil Plants
From Theodore Delevoryas' Morphology and Evolution of Fossil Plants

"The most convincing evidence of plant evolution is the record of fossil plants. Documented deep in the earth's crust are the progressive changes and modifications undergone by various groups of the plant kingdom through millions of years. Every year, students of fossil plants unearth new specimens that help piece together what paleobotanists hope some day will be a continuous story of the development of the plant kingdom from an age of more than one billion years ago to the present time. During that long period of time profound changes have occurred in the plant world. Groups have arisen, flourished, and become extinct; without the fossil record present-day botanists would be unaware that such groups of plants ever existed."

History of Grass
From Nicolette Hahn Niman's Defending Beef
(The Case For Sustainable Meat Production)

"To fully appreciate the importance of grass, we must go back much further in time, even before the appearance of Homo sapiens. Prehistoric earth was not, as is commonly believed, thickly carpeted from ocean to ocean with damp ferns and towering trees. Ancient flora was highly varied, and from at least 65 million years ago, it included grasses. Probably not coincidentally, and likely due to climatic changes, grasses emerged around the time of the disappearance of dinosaurs, which had previously populated the earth for 160 million years.

"From approximately 20 to 10 million years ago, grass began to proliferate in earnest. Changes in the earth's climate are again likely responsible. Initially, carbon dioxide levels dropped, followed by a period of time in which atmospheric carbon dioxide sharply increased, to about 400 ppm (similar to today's level). Amid such fluctuations, grasses had a photosynthetic advantage over other plants. Around the same era, forest-clearing wildfires became common occurrences on the earth. Into these newly opened spaces, grasses (along with forbs, other non-woody vegetation) filled the voids. Resulting from some combination of atmospheric changes and forest fires (scholars debate which factor was more significant), grasses carpeted the globe." pp 57-58

"There are substantial scientific evidence both that humans influenced the way grasses evolved and that grasslands were a major factor in the way humans evolved. Born to Run, Christopher McDougall's fascinating best-selling book about traditional people who engages in long-distance running, expounds on the idea, known as the Running Man theory. It argues that it is the human's capacity to run extremely long distances (not just 26 miles, but 50, 75, and more) - farther than nearly any other animal - that was the secret to our ancestors' hunting success. Not speed but endurance was the species' trump card. However, hunting based on outlasting your prey only works if there are vast open ranges where the prey can be spotted and followed even after a burst of sprinting to escape. Thus, the theory argues, open, grassy areas were essential to humanity's success as a species." p. 59

The Sexual Selection and Evolution of Plants:
From Bill Nye's, Undeniable (Evolution and the Science of Creation) pp. 58-59

"In fact, lilies, like every other sexual organism on the planet, work pretty hard to produce a means to mate. If you haven't already, stop and think about how much energy a plant puts into creating a flower. In general, a green plant such as a lily, rose, hickory tree, Ponderosa pine, or bull kelp, has leaves, needles, or fronds to collect sunlight. And in general, the other structures such as stems, trunks, or stipe serve to support the leaves in an efficient or efficient-enough fashion. What else does a plant do besides look to soak up light? The answer is simply: make more plants, which is not easy.

"Plants go to great lengths to reproduce. It takes a lot of a lily's energy to produce flowers. It takes a great deal out of an oak tree to make thousands of acorns. In that case, the tree is, in turn, counting on squirrels to forget where they hid a few acorns, so that a new oak tree might grow nearby. Apple trees and orange trees go to all kinds of trouble to grow fruit, so that some guy like me or my local Los Angeles 'citrus mice' (rats) will wander off with a piece and spit out the seeds on suitable moist soil. Palm trees grow coconuts the size and toughness of cannonballs, so that they can float their seed to another island. Just consider how much less energy it would take a lily or a cornstalk to grow and thrive if it didn't have all these seeds to sow.

"And there is more. It's not just that these organisms are growing viable seeds. It's also that these organisms are growing structures such as flowers, pistils, stamen, eggs, and pollen to get a mix of genes, before the seeds are sent off. It's all sexual.

"A rosebush has woody canes to give it structure. It has thorns to discourage animals from climbing on the canes or perhaps using them for a nest. Producing canes takes energy. But just look at the resources and energy rose plants expend creating elaborate blooms and hips (roe seeds). They produce attractive flowers not to avoid germs or to make it through a cold tough winter, but to get their genes mixed with the genes of other individuals that are selected on account of sex. They do it to attract pollinators, like bees and birds, that stop by for some nectar and carry some pollen when they fly away."

A Sterile Earth
From Donald R. Prothero's, The Story of Life in 25 Fossils
(Tales of Intrepid Fossil Hunters and the Wonders of Evolution) pp. 68-69

"We look at the amazing forests and grasslands of Earth and glorify in the 'green planet' that grows so much plant material that can sustain so many different kinds of animal life. But it has not always been this way. Earth was a hostile, barren place for most of its 4.5-billion-year history. There were no land plants that could live on its harsh surface, so bare rock was exposed to intense chemical weathering, releasing all its nutrients into the ocean without any marine organisms to absorb them. The only photosynthesizing organisms for the first 1.5 billion years of life's history were blue-green bacteria (cyanobacteria), which lived in the shallow waters of the oceans and formed stromatolites. Then, about 1.8 billion years ago, we the first evidence of algae, which are true plants with eukaryotic cells (having a discrete nucleus for their DNA, plus organelles such as chloroplasts for their photosynthesis). Both cyanobacteria and algae continued to grow huge mats of slime on the shallow seafloor."

"The extremes of heat and cold, the intensity of rainstorms and runoff without the protection of plant cover, plus the absence of an ozone layer (because of the lack of free oxygen in the atmosphere) meant that few plants could venture out of the water and onto land. As long as there was no ozone layer, both plant and animal cells would be bombarded with high levels of ultraviolet radiation, which causes mutations in genes and eventually kills cells. Only the protection of being immersed in water screens most life from ultraviolet light without the protection of the ozone layer.

"Based on chemical evidence, it appears that about 1.2 billion years ago the first organisms began to colonize land. They were probably very simple associations of algae and fungi called cryptogramic soils, which are very similar to the crusts of organic material found on the desert surface when it is not disturbed. The lichens that break down bare bedrock are an example of this because lichens are not an organism, but a symbiotic association of algae and fungi. The cryptogamic soils would have been the only life on Earth's surface and would have served to help bind and stabilize the land against erosion by wind and rain, even as they helped marine algae and cyanobacteria pump more and more oxygen into the atmosphere.

"Naturally, with no significant plant resources to consume on land, there was no animal life on land, either. Animal life needs not only food to eat, but also enough free oxygen in the air to breathe - which apparently did not accumulate in the atmosphere until about 530 million years ago. The combination of extreme heat and cold, lack of shelter and food, and unchecked erosion made the land a dangerous habitat that most creatures could not yet exploit."

Photosynthesis and Chlorophyll

By Kristian Peters -- Fabelfroh - Self-photographed, CC BY-SA 3.0

Photosynthesis is how plants and some microorganisms absorb energy, from light, to make carbohydrates. Photosynthesis is a chemical process which uses sunlight to turn carbon dioxide into sugars. The sugars are then used by the cell as energy, and to build other kinds of molecules. Basically, photosynthesis converts light energy into chemical energy.   Chlorophyll is essential for photosynthesis. Chlorophyll molecules are arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. (left photo)   Autotrophs are organisms that make their own biological materials and energy - they are the organisms which create sugars, proteins, lipids, and other materials for life. All other organisms survive by eating autotrophs. The two major types of autotrophs are chemoautotrophs and photoautotrophs.   Organisms that get their energy directly from chemical reactions are called chemoautotrophs. Chemoautotrophs are cells that create their own energy and biological materials from inorganic chemicals.   Plants and photosynthesizing algae are photoautotrophs - they use energy from sunlight to make their biological materials.

Definitions

• Abscission Zone a layer of cells at the base of a leafpetiole, flower, or fruit stalk, the weakening of which causes the organ to separate from the plant
• Allelopathy release of chemicals by a plant to discourage the growth of other plants near it
• Allopolyploid a hybrid arising from the combination of chromosomes from two different species
• Aneuploidy a condition in which chromosome numbers are notin exact multiples of the haploi set; having extra or missing chromosomes within a nucleus
• Angiosperm a member of a class of plants characterized by the formation of fruits containing seeds.
• Anther the pollen-bearing part of a stamen
• Antheridium the male sex organ of plants other than gymnosperms and angiosperms
• Apical Meristem a region of actively dividing cells at the tip of a growing root system
• Archegonium the female sex organ of plants, other than angiosperms
• Autotrophic Nutrition a form of nutrition in which complex food molecules are produced by phtosynthesis from carbon dioxide, water, and minerals
• Auxin a plant hormone that principally controls cell elongation
• Axil tje amg;e betweem tje i[[er sirface pf a ;eaf amd tje ste, tp wjocj ot os attacjed
• Biennial a plant completing its life cycle within tow growing periods
• Callose a plant substance created and deposited in the pores of phloem sieve plates, especially in response to injury
• Callus a corky tissue developed by woody species to cover wounds
• Capillary Water water held in the tiny spaces between soil particles or between plant cells
• Cellular Respiration the chemical breakdwon of food substances, resulting in the liberation of energy
• Chelate an organic substance to which metals such as iron are bound and from which they are released
• Chlorophyll a green plant pigment located in chloroplasts
• Chloroplast a cellular body in which photosynthesis occurs
• Cladode a flattened stem performing the function of a leaf, such as a cactus pad
• Cleistogamy the development of viable seed from unopened, self-pollinated flowers
• Contractile Root a thickened root serving to pull a corm, bulb, or rhizome deeper into the soil
• Cork the protective outer tissue of the bark
• Cork Cambium a layer of cells in the bark giving rise to the cork; a lateral meristem
• Corm a short, swollen underground stem in which food is stored
• Cotyledon a seed leaf; a food-storage structure in seeds
• Cuticle a waxy layer on the outside of leaves, herbaceous stems, and fruits
• Cutin the waxy substance forming a cuticle layer
• Cytokinin a plant hormone primarily stimulating cell division
• Cytoplasm the living protoplasm of a cell, excluding the nucleus
• Deciduous shedding all of the leaves in one season
• Diageotropic horizontal growth of a plant part
• Dicot a member of a subclass of angiosperms characterized by having two cotyledons in their seeds
• Dioecious having male and female sex organs on separate individuals
• Diploid having two sets of chromosomes
• Drip Tip a ponted leaf tip helping to drain water from the leaf surface
• Eff a female sex cell
• Endodermis a layer of cells in roots between the cortex and vasular tissues
• Endosperm food-storage tissue in seeds
• Epigeous Germination seed germination in which the cotyledons are raised above the soil surface
• Epiphyll an organism such as a fungus or moss growing on the surface of a leaf
• Epiphyte a plant growing on another plant for physical support
• Fiber a long, thick-walled cell that dies at maturity
• Filament the stalk of a stamen bearing an anther
• Fruit a mature ovary
• Gamete a sex cell; sperm or egg
• Gametophyte a haploid, gamete-producing plant in the alternation of generations
• Genotyp the genetic constitution of an organism
• Genus a taxonomic category containing related species
• Geotropism growth of a plant organ in response to gravity
• Germination the beginning of growth of a seed, sport, or pollen grain
• Gibberellin a plant hormone regulating several processes including internode elongation and cell enlargement
• Granum a stack of platelike, pigment-containing structures in a chloroplast
• Gymnosperm a members of a class of plants forming seeds in an exposed condition, frequently in cones
• Haploid having one set of unpaired chromosomes
• Haustorium an organ produced by a parasite that penetrates and absorbs water and nutrients from the host's tissues
• Heterotrophic Nutrition a form of nutrition in which the organism depends on organic substances as a food source, as is the case with humans
• Heterozygous having both dominant and recessive genes for a particular characteristic on homologous chromosomes
• Homologous Chromosomes matching chromosome pairs
• Homozygous having identical genes on homologous chromosomes
• Hyupocotyl the part of a seedling between the roots and the place of attachment of the cotyledons
• Hypogeous Germination seed germination in which the cotyledons remain below the soil surface
• Imbibition the process of water absorption by a dry substance or structur, causing it to swell
• Inflorescence a shoot bearing clusters of flowers
• Insectivorous Plant a plant that captures and digests insects as a source of nitrogen
• Leaf an outgrowth of a stem; the principal organ of photosynthesis
• Lenticel a small, gas-exchange opening in the cork of a woody stem
• Lignin a tough, durable plant substance deposited in cell walls, expecially in wood
• Megaspore a spore that develops into a female gametophyte
• Meiosis a cell divisional process in which the chromosome number is reduced by half
• Meristem a region where cells actively divide
• Mesophyll the parenchyma tissue of a leaf between the upper and lower epidermis, including palisade and spongy cells
• Microspore a spore that develops into a male gametophyte
• Mitochondria cellular bodies in which cellular respiratio occurs
• Monocot a member of a sublcass of angiosperms characterized by the presence of one cotyledon in the seeds
• Monoecious bearing separate male and female flowers on the same plant
• Mycorrhiza an association between a fungus and the roots of a higher plant
• Nastic Movement a movement of a plant part (such as a leaf) not caused by an external stimulus
• Necrosis the death of plant tissue
• Organelle a cell structure performing a specific function
• Ovary the basal portion of a pistil that becomes a fruit
• Ovule structure within the ovary containing the egg cell
• Palmate Venation a vein pattern in which the major veins radiate from one point
• Parenchyma a thin-walled, undifferentiated cell
• Parhenocarpy development of a fruit without pollination, fertilization, or seed development
• Pectin a substance in cell walls binding cells together
• Perennial a plant living through several growing seasons
• Pericarp the fruit wall; dev=rived from the ovary wall
• Pericycle a root tissue giving rise to branch roots
• Petiole a leaf stalk
• Phenotype the physical appearance of an organism
• Phloem the food-conducting tissue of plants
• Photoperiodism the initiation of flowering in response to relative lengths of day and night
• Photosynthesis the process in which light energy is used to form toods from carbon dioxide and water
• Phototropism curvature of a plant organ in response to light
• Phytoalexin a chemical produced by a plant to inhibit the growth of pathogens
• Phytotoxin a plant product having toxic effects on herbivores and other invasive organisms
• Pistil the female part of a flower
• Plagiotropic growth of a branch at an angle
• Plasmodesmata fine strands of cytoplasm that pass through cell walls, connecting adjacent cells
• Plasmolysis shrinkage of cytoplasm away from the cell wall as a result of excess water loss
• Pollen a structure that develops from a microspore in angiosperms and gymnosperms to become a male gaetophyte
• Polyploid having three or more sets of chromosomes per cell
• Protoplasm the living substance of cells, including cytoplasm and nucleus
• Radicle an embryonic root
• Raphide a needle-shaped crystal of calsium oxalate in certain species' cells that dters herbivores
• Resin a viscous, protective secretion of many conifers that is insoluble in water and hardens on contact with air
• Rhizome an underground, horizontal stem
• Ribosome a cellular particle; the site of of protein synthesis
• Sand an inorganic soil component, the particles of which range betwen 0.02 and 2 mm diameter
• Saprophyte an organism that obtains food from dead organic matter
• Seed a reproductive structure formed from the maturation of an ovule and containing an embryo and stored food
• Seismonastic Motion a response to vibrations or touch
• Senescence the aging process; a breakdown of cellular structures leading to death
• Sieve Plate the perforated end wall of a sieve tube member
• Sieve Tube a food-conducting cell
• Silt an inorganic soil component, the particles of which range between 0.002 and 0.02 mm diameter
• Sorus an area of spore production on the underside of a fern leaf
• Species a group of individuals sharing many characteristics and interbreeding freely
• Sperm a male sex cell
• Spore a reproductive cell that grows directly into a new plant
• Sporophyte a diploid, spore-producing plant in an alternation of tnerations
• Stamen the male part of a flower, consisting of an anther and filament
• Starch the principal food-storage substance of higher plants; a carbohydrate consisting of numerous glucose units
• Stigma the part of a pistil that receives pollen
• Suberin a fatty plant substance present in the walls of cork cells
• Tannin a substance occurring in the bark or leaves of some species, functioning to protect against predators
• Thigmotropism a growth response to touch
• Tracheid a water-conducting cell in gymnosperms and other lower vascular plants
• Tropism a growth curvature of a plant part caused by some external stimulus such as light or gravity
• Turgid swollen and firm due to internal water pressure
• Turgor Pressure the pressure developed in a cell as it becomes filled with water
• Twiner a stem growing in a spiral fashion around a supportive object
• Vacuole a fluid-filled sac within a cell
• Variegation, Variegated an inherited, irregular pattern of color in a leaf or petal
• Vascular Cambium a narrow cylinder of cells that gives rise to secondary xylem and phloem; a lateral meristem
• Velamen a water-absorbing tissue on the outside of orchids' aerial roots
• Vessel a water-conducting cell in most angiosperms
• Vivipary seed germination before dispersal
• Xanthophyll a yellow or almost colorless photosynthetic pigment
• Xylem the water-conducting tissue of plants
• Zygomorphic Flower a flower divisible into two similar halves along one plane only
• Zygote the product of union of a sperm and egg; a fertilized egg

Links:

Back to Roger J. Wendell's Home Page...

Abbey | About | Blog | Contacting Me | Copyright | Disclaimer | Donate | Guest Book | Home | Links | Site Index | Solutions | Terms, Conditions and Fair Use | What's Changed or New?
Copyright © 1955 -