I wondered what the number of known plants was. The study of plants originated in prehistory as herbalism. Humans needed to identify edible, medicinal and poisonous plants. It was in the 18th century that steps were taken toward a unified hierarchical classification of plant species. In 1753 Carl Linnaeus (known as Carl von Linné after his ennoblement in Sweden) published his ‘Species Plantarum’ that remains the reference point for modern botanical nomenclature. Nomenclature means an international system of terms used in biology for kinds and groups of plants and animals.
One study gives the total number of described flora in the world as 268 650. Others have given as high a number as 350 000. The most agreed upon numbers seem to be between 300-315 thousand species of plants.
Plants or Viridiplantae, in Latin meaning green plants, are multicellular eukaryotes-organisms whose cells contain a nucleus and other structures (organelles) enclosed within membranes-of the kingdom Plantae. In biology the major taxonomic ranks of plants are as follows: Life, Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Plants form a clade, a single branch on the tree of life that includes the flowering plants, gymnosperms such as conifers, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Red and brown algae, the fungi, archaea and bacteria are excluded. Modern botany has become highly complex and detailed over the years.
Unlike common names, botanical or scientific names are applied to only one kind of plant. They typically consist of two words; the first is called the genus name, the second the species name. Together they define a single unique type of plant. The words that make up the scientific name of a plant all mean something. They are Latin or Latinized words. Sometimes they are the old Roman name for a particular kind of plant, Latinized words of other languages are also used, descriptive names or terms such as alba-white, sanguinea-blood-red, or names of people for which the plant was named such as Forsythia, Magnolia.
The rules for officially naming plants are established by botanists who gather periodically in International Botanical Congresses (IBC). The next one is scheduled to be held in Shenzhen, China in 2017.
The naming of plants is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN) and the International Code of Nomenclature for Cultivated Plants (ICNCP, Cultivated Plant Code). There are systems of plant taxonomy and the latest APG III-Angiosperm Phylogeny Group III system was published in 2009.
Learning all this made me think of the earth’s past. A wide surface of the earth was covered with dense forests until humans began farming which required opening up land for cultivation and pastures. In time, logging, urban sprawl, human-caused forest fires, acid rain, invasive species and shifting agriculture brought about loss of old-growth forests. Natural causes such as forest fires, insects, disease, weather, and competition of species cause loss of forests also. Secondary forests with smaller trees developed instead. “Today, more than 75% of the world’s remaining old forests lie in three countries-the Boreal forests of Russia and Canada and the rainforest of Brazil” (http://en.wikipedia.org/wiki/Forest).
When trees go entirely marshes and wild flower patches arise. These can be so lovely. Many beautiful plants that are considered weeds grow in these places. I will quote Wikipedia in defense of the weeds that grow in wildflower patches and meadows.
“A weed is a plant considered undesirable in a particular situation. Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks. Taxonomically, the term 'weed' has no botanical significance, because a plant that is a weed in one context is not a weed when growing in a situation where it is in fact wanted, and where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed, such as a wild bramble growing among cultivated loganberries. Many plants that people widely regard as weeds also are intentionally grown in gardens and other cultivated settings. The term is also applied to any plant that grows or reproduces aggressively, or is invasive outside its native habitat.” (http://en.wikipedia.org/wiki/Weed)
In Kanata, Ottawa where my younger daughter lives I came across a lovely wild flower patch in July, 2014. About five days after I took these photos the field was dug up and a sales shed was in place for the sale of the condos that were going to be built there.
A lovely yellow ‘weed’ drew my attention.
Lotus pedunculatus (formerly Lotus uliginosus) is a member of the pea family Fabaceae. It is a perennial growing primarily in Western Europe and the Mediterranean coast of North Africa. It thrives in damp, open locations growing 20-80 cm tall, with leaflets 10-25 mm long and 10-20 mm broad. The ones I saw had six golden-yellow flowers 10–18 mm long forming an umbel at the tip of the upright stem.
The common name for it is a long one: Marsh birdsfoot trefoil.
Here was a plant that had travelled from Europe. Once I noticed this lovely little flower I started seeing it in the gardens and lawns all over Kanata.