Classification and Taxonomy
Have you ever wondered why Botanical or Scientific names are so important?
Well just like a specific set of coordinates (latitude and longitude) or a postcode/zip code. Botanical names or binominal nomenclature as its full description goes, are specific to a certain plant formed of two names; ‘Genus’ followed by ‘species’. These two names are universally identify a particular plant no matter the language.
This is unlike common names, where plants can have multiple names in different countries and cultures. So wherever you are or whatever language you speak, you can identify that given plant. This system was first developed in the 1700s by Carolus Linnaeus who lived in Uppsala in Sweden.
An example of the confusion caused by common names includes the White Waterlily or ‘Nymphaea alba’, which has 15 different common names in English alone. This does not include the other 240 names in other languages. Another common example is the pepper. You can get bell peppers that are not spicy and come in green, red, yellow and orange. They belong to ‘Capsicum annum’. However, the pepper that some use on their food as a seasoning actually belongs to ‘Piper nigrum’. This does not include the chilli peper which is also another form of Capsicum.
Description of Taxonomy
Taxonomy is the study of principles and practices of classification. Strictly applying to the study and description of variation in the natural world and the subsequent compilation of classifications.
Plants are classified in a hierarchical system which attempts to illustrate the evolutionary relationships between various groupings. Broadly speaking there are five Kingdoms: ‘Animalia’ or animals,‘Plantae’ or plants,‘Fungi’, ‘Prokaryotic’ or bacteria (cells without a nucleus) and finally ‘Protista’ or eukaryotic (cell with a nucleus) bacteria including algae. As in many theories there are issues with the system, which currently results in a constant state of flux. This is more noticeable on the lower levels; however, even at the highest levels, groups are questioned and are cause for debate between taxonomists.
Various groupings in this list: Magnoliidae, Magnoliopsdia, Ranunculares and Ranunculaceae are called a taxon. In everyday mitigation, full classification is not necessary; instead the plant is referred to Genus and species. In addition: A form is a type of plant within a species that has little differences, such as the shape of the leaves or colour of flora. Deliberate hybridisation results in a cultivar, and can be reproduced to make increased amounts of the same plant.
Requirement for classification
The number of different kinds of plants is exceedingly great; scientists are faced with an estimated total of 300,000, if included fungi, moulds, mushrooms and toadstools; it would increase to 450,000. Furthermore scientists’ still have much to learn about the world’s plants. Scientists’estimate that 15-20% of plant species have not yet been describe and at present, approximately 2,000 new species of plants are discovered per annum. It has been an estimated that there are over 14 million living species on Earth, though only 1.8 million have been given botanical names.
By using the Linnaean classification system, we are able to classify plants and animals and in turn learn more about our own biological evolution. This just demonstrates to us, that the plant kingdom is extremely large and diverse. In other words, it is the extensive size and great diversity of the Plantae kingdom which makes it necessary for plants to be classified, especially in industries like Horticulture which come in contact with plants on a day to day basis.
The purpose of a designation is to act as an efficient means of reference or an ‘aid’ to communication. A plant name must be unambiguous if so this breaks down communication. An example of this would be, if a same plant is known to different people by different names, then they will fail to understand one another and confusion will result in when they try to communicate.
Linnaeus and his importance
Greek and Roman scholars laid the foundations of the method of naming flora. The bi-nominal classification system used today was largely established in the 18th Century by Swedish Botanists Carl von Linne ‘Linnaeus’(1707-1780). Linnaeus classified plants with two botanical words rather than descriptive text. The first word describes the Genus and the second species, for example, Dicksonia antarctica. ‘Dicksonia’being the genus and ‘antarctica’being the species. Prior to 1753, plants were known by phrases, which were difficult to distinguish from simple descriptions. An example of this method is a plant called, Achillea ptarmicaonce carried the designation ‘Achillea foliis lanceolatis acuminates argute serrates’, which translates as Achillea with lanceolate leaves which taper to a sharp point and have sharp pointed, saw-toothed edges.
The genus comprises of related plants with features in common, such as Lilium which all derive from bulbs. Species are a group of plants that consistently and naturally reproduce themselves, mostly by seed or vegetative. Species regularly generate plant populations that share similar characteristics. The first letter of the genus is always capitalised and italics are used for the whole name for example: Cobaea scandens, observe no capital was used for the species, as it is not as important as the genus.Also the scientific names are only abbreviated when several species from the same genus are being used, for example: Passiflora caerulea, P. incarnateand P. quadrangularis. ‘The purpose of a name is to act as an easy means of reference. It is, in other words, an aid to communication’.
Using this structure allows horticulturists, botanists and other related industries to communicate clearly, so you can be assured you are getting what you are seeking. Bi-nominal nomenclature gives us the scientific name which is understood globally, otherwise known as a‘universal language’. If you are visiting gardens overseas, you would see baffling collections of names on plant labels, but as long as the scientific name is also included, you can be assured of what you are seeing. It also enables the transfer of clear and easily understood information between people working with cultivated plants. Rather than being a framework, which is aimed to catalogue all living organisms, the bi-nominal system has more practical aims, for example to create a basis for Plant Breeders’ Rights Legislations and to uniform seed registration.
The ICBN and ICNCP
The International Code of Botanical Nomenclature (ICBN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants. Its intent is that each taxonomic group or ‘taxa’ of plants has only one correct name, that is accepted globally. When a plant is discovered and believed to be new to science, it is given a botanical name and formally described with a botanical diagnosis according to a set of agreed international regulations. An innovation introduced to the latest edition of the ICBN regulations, is the ‘Standard Specimen’ - a type of voucher specimen, stored in an appropriate herbarium for posterity, to help identify a new cultivars.
The ICBN ensures that plants have the appropriate designation within the relegations of botanical naming. Without this system in place there would be nobody to monitor naming, so various plants would have an inappropriate designation thus destabilising the mitigation of taxonomic groups. This would result in ambiguity or even confusion through the scientific world. The ICBN also seeks to develop the taxonomy of plants in the instance ofAndrographis echioides it was segregated into a new genus Neesiella,by Sreemandhaven (1967) but the generic name Neesiella was already attributed to a genus Hepaticae by Schiffner (1893) and hence Sreemandhaven’s name is illegitimated. Later Sreemandhaven (1968) changed the genus to Indoneesiella.
The ICBN Code frequent developments in nomenclature have caused disputes among plant scientists as well as agriculturists and horticulturists. There are two main reasons for change, firstly, advancement in scientific knowledge and secondly, authors have not followed the provisions of the code. Ironically the code formulated to bring stability has in fact has become a source of instability due ‘automatic transfers’ or changes within plant taxonomy.
The International Code of Nomenclature for Cultivated Plants (ICNCP) regulates the names of ‘cultigens’or plants that have an origin due to human activity. These for the most part are plants with names in the category of cultivars and groups. Examples of plants that are regulated are as follows: Clematis alpina 'Ruby' a cultivar with a species, Magnolia 'Elizabeth' a hybrid between two species, Rhododendron boothii Mishmiense Group: a Group name, Crataegomespilus a graft of a Crataegus and Mespilus and Apple 'Jonathan' allowed use of an unambiguous name with a cultivar epithet.
The requirement for a comprehensive set of practical, understandable and internationally acceptable regulations on the naming of ‘cultivated’ plants has long been evident.
The first major step in the formulation of the International Code set out below was made in 1862 by Alphonse de Candolle in a letter subsequently placed before The International Horticultural Congress of Brussels, 1864 from there a temporary code was setup and from there subsequent renewals were followed until 1952, where The ICNCP was formed. The ICNCP like the ICBN ensures that no misunderstanding and confusion occur in cultivar names, which are used throughout the commercial world.
To conclude, taxonomy is the classification of organisms into groups based on similarities of structure. It is necessary to classify plants in horticulture mainly due to the huge volume of diverse plants species and an estimated 2,000 new species discovered per year. It is highly important that Linnaeus’s bi-nomial system of nomenclature is in place, to describe in a ‘common language of men’. thus aiding global understanding and communication. The ICBN regulate plant names to ensure that taxonomy rules are followed, and The ICNCP regulates cultivated plants to aid the commercial and scientific industries.
Taxonomy, what is the difference?
Taxonomy is the method by which scientists and conservationists classify and organise the vast diversity of living things on this planet in an effort to understand the evolutionary relationships between them. Modern taxonomy originated in the mid-1700s when Swedish-born Carolus Linnaeus (also known as Carl Linnaeus or Carl von Linné) published his multi-volume Systema naturae, outlining his new and revolutionary method for classifying and especially, naming living organisms. Prior to Linnaeus, all described species were given long complex names that provided much more information than was needed and were clumsy to use. Linnaeus took a different approach: he reduced every single described species to a two-part Latinized name known as the binomial name. Thus, through the Linnaean system a species such as the dog rose changed from long, unwieldy names such as Rosa sylvestris inodora seu canina and Rosa sylvestra alba cum rubore, folio glabro to the shorter, easier to use Rosa canina. This facilitated the naming of species that, with the massive influx of new specimens from newly explored regions of Africa, Asia, and the Americas, was in need of a more efficient and usable system.
Although trained in the field of medicine, botany and classification were the true passions of Linnaeus and he actively explored northern Europe and described and named hundreds of new plant species during his lifetime. As well Linnaeus spent a great deal of time describing and naming new plant specimens that were sent to him from around the world by other botanists including from the newly explored regions of the New World. Linnaeus classified this multitude of new plant species based upon their reproductive structures, a method which is still largely in use today. In fact, the majority of the species described by Linnaeus are still recognised today indicating how far ahead of his time he truly was. Although somewhat rudimentary by today’s standards, Linnaeus’ methods of describing species in such a way as to represent the relationships between them changed the face of taxonomy and allowed biologists to better understand the complex natural world around us.
More details about Carl Von Linnaeus
23 May 1707 – 10 January 1778, was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology.
Linnaeus was born in the countryside of Smaland, in southern Sweden. His father was the first in his ancestry to adopt a permanent last name; before that, ancestors had used the patronymic naming system of Scandinavian countries. His father adopted the Latin-form name Linnaeus after a giant linden tree on the family homestead. Linnaeus got most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735–1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands. He then returned to Sweden where he became professor of botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 60s, he continued to collect and classify animals, plants, and minerals, and published several volumes. At the time of his death, he was renowned as one of the most acclaimed scientists in Europe.
The Swiss philosopher Jean-Jacques Rousseau sent him the message: "Tell him I know no greater man on earth. The German writer Johann Wolfgang von Goethe wrote: "With the exception of Shakespeare and Spinoza, I know no one among the no longer living who has influenced me more strongly.” Swedish author August Strindberg wrote: "Linnaeus was in reality a poet who happened to become a naturalist” Among other compliments, Linnaeus has been called "Princeps botanicorum" ("Prince of Botanists"), "The Pliny of the North" and "The Second Adam.”
In botany, the author abbreviation used to indicate Linnaeus as the authority for species names is simply L.
Linnaeus published Philosophia Botanica in 1751. The book contained a complete survey of the taxonomy system Linnaeus had been using in his earlier works. It also contained information of how to keep a journal on travels and how to maintain a botanical garden.
In 1753 Linnaeus published Species Plantarum, the work which together with his earlier work Systema Naturae—is internationally accepted as the beginning of modern botanical nomenclature. The book contained 1,200 pages and was published in two volumes. It described over 7,300 species. The same year he was dubbed knight of the Order of the Polar Star by the king. Linnaeus was the first civilian in Sweden to become a knight in this order. He was then seldom seen not wearing the order.
Linnaeus was relieved of his duties in the Royal Swedish Academy of Science in 1763 but continued his work there as usual for more than ten years after. In December 1772 Linnaeus stepped down as rector at Uppsala University, mostly due to his declining health.
Linnaeus' last years were troubled by illness. He had suffered from a disease called the Uppsala fever in 1764 but survived thanks to the care of Rosen. He got sciatica in 1773 and the next year he had a stroke which partially paralysed him. In 1776 he suffered a second stroke, losing the use of his right side and leaving him bereft of his memory; while still able to admire his own writings, he could not recognize himself as their author.
In December 1777 he had another stroke which greatly weakened him, and eventually led to his death 10 January 1778 in Hammarby. Despite his desire to be buried in Hammarby, he was interred in Uppsala Cathedral 22 January.
His library and collections were left to his widow Sara and their children. Joseph Banks, an English botanist, wanted to buy the collection but Carl refused and moved the collection to Uppsala. However, in 1783 Carl died and Sara inherited the collection, having outlived both her husband and son. She tried to sell it to Banks but he was no longer interested; instead an acquaintance of his agreed to buy the collection. The acquaintance was a 24 old medical student, James Edward Smith who bought the whole collection: 14,000 plants, 3,198 insects, 1,564 shells, about 3,000 letters and 1,600 books. Smith founded the Linnean Society of London five years later.
The classification of plants
Plants and all organisms are classified in a hierarchical system that attempts to illustrate the evolutionary relationships between the various groupings within the hierarchy. This concept of relatedness forms the backbone of modern classification schemes. Scientists who attempt to classify organisms and place them within an evolutionary framework are called Taxonomists, the most famous of which would be Linnaeus himself. At the broadest level, all organisms on the planet are classified into 5 Kingdoms: Fauna (animals), Plantae (plants, some muilticelluar algae), Fungi (fungi), Monera (prokaryotic bacteria), and Protista (eukaryotic bacteria and most algae.), representing the most ancient branches of the evolutionary tree of life. Organisms in any given Kingdom may be separated from organisms in any other Kingdom by many hundreds of millions, if not billions, of years of evolution.
Historically all organisms known were grouped into only two Kingdoms: organisms that had finite growth, moved, and ate were grouped into the Kingdom Fauna, while organisms that had indefinite growth did not move, and did not eat were grouped into the Kingdom Plantae. Of course, as science progressed, it became increasingly evident that such a simplistic approach to taxonomy was ineffective and many species were found that did not fit either grouping particularly well. The proposal to move to an eight-Kingdom system suggests that our current classification system, with its five Kingdoms, may yet change again as our understanding of the diversity of organisms around us continues to grow.
Within each Kingdom the organisms are grouped into several Phylum, also known as Divisions, which represent smaller groupings of more recognizable forms. Although the Kingdom Fauna contains a large number of Phyla (such as chordates, including vertebrates, echinoderms, annelids, arthropods, and soon on), Kingdom Plantae contains only ten. The Phylum Bryophyte (mosses, liverworts, hornworts), the most primitive of all true plants, differs from other plant Phyla in that it is non-vascular, meaning that it lacks water-conducting tissues which bring water from the roots of the plant up into the crown, and that the gametophyte (vegetative) generation predominates over the sporophyte (reproductive) generation. The Phyla Psilophyta (whisk ferns), Lycopodiophyta (club-mosses, spike-mosses, quillwort’s), Equisetophyta (horsetails), and Polypodiophyta (true ferns), including all vascular plants that reproduce using spores, also form an ancient, though largely artificial, grouping and are often referred to as Pteridophytes. The Phyla Cycadophyta (cycads), Ginkgophyta (ginkgo), Gnetophyta (vessel-bearing gymnosperms), and Coniferophyta (conifers) form a second primitive grouping of vascular plants, known as Gymnosperms, which are characterized by the presence of naked seeds. The final Phylum, Magnoliophyta, contains all of the vascular, flowering plants that are considered to be the most advanced and recently-evolved plants occurring on the planet today.
Within each Phylum, the organisms involved are grouped into progressively smaller, more refined groupings of similar individuals. Below Phylum, organisms are grouped into Classes, Orders, and Families, the latter being the largest-order taxonomic grouping that is commonly used by amateur botanists. As an example the Phylum Magnoliophyta is split into two well known Classes: Magnoliopsida (Dicotyledons) and Liliopsida (Monocotyledons) based on a variety of features from leaf venation and flower structure to growth form, root structure, and seed structure, each class with its subsequent Orders and Families. Each family is further divided into Genera (Genus) representing organisms with similar morphology, structure, reproductive organs, and, perhaps most importantly, evolutionary history. These genera represent groupings that many of us are most familiar with such as: Rhododendron, Rosa, Chrysanthemum and are designed to illustrate that the individual organisms grouped within the same genus are very closely related to each other. In fact, the genus is the taxonomic grouping that represents the closest relationship between organisms which at the smallest taxonomic level, are called Species. Each individual species is given a specific name that when combined with the generic name produces the two-term binomial naming system that Linnaeus pioneered. For example, within the genus Rosa are a variety of species such as acicularis, nutkatensis, and woodsii. Through the binomial naming system, these species become Rosa acicularis, R. nutkatensis and R. woodsii.
As with many scientific theories or strategies, there are problems with this system in the way it is currently applied and as a result it is in a continual state of flux, especially at the lower levels of the hierarchy. Even at the highest level (Kingdom), several groups are still cause for debate among taxonomists as to their placement. For example how do we classify lichens? Lichens were originally placed within the Kingdom Plantae until further research showed that what we call “lichens” are actually a symbiotic relationship between certain species of fungi and certain species of algae. The two species, which can often survive independent of each other, combine to form a third plant-like species of organism called lichen that differs greatly from either of its two parent species yet functions as its own reproductive, evolutionary organism. Currently lichens are included within the Kingdom Fungi since the fungal partner is the driving force behind the union but this treatment still does not really fit with traditional taxonomy.
Another example of how nature continually confounds attempts to classify it is the vast array of plant-like organisms grouped under the term “algae.” The confusion results from the fact that most algae are unicellular or, if muilticelluar, composed of a single or very few cell types amassed together to function as a larger individual. So, do we classify muilticelluar algae based on the characteristics of the single cell or as an independent muilticelluar organism? Most algae are currently placed within the Kingdom Protista despite their often plant-like appearance, with only a few of the multi-cellular forms remaining within the Kingdom Plantae. This treatment is not followed by all authors, however, as some retain all of the algae as a subkingdom within the Kingdom Plantae. Regardless of the treatment, it is obvious that the great diversity within the group algae, as well as its unusual morphological and cellular characteristics is a hindrance to botanists who attempt to classify them within our current taxonomic systems.
What defines a species?
At the lowest level of the classification hierarchy is the species, a human-derived concept that, to this day, is still not completely understood by scientists. The general consensus in past decades has been that a “species” is a group of similar individuals which can reproduce successfully with each other while at the same time being reproductively isolated from other similar species. This interpretation worked reasonably well when it was first proposed, but the more we learn about ecological systems the more apparent it becomes that nature is by no means so simple. The evolutionary process is a continuum whereby a portion of the population of one entity gradually becomes more and more distinctive and discrete eventually reaching a state in which it is reproductively isolated from its parent “species.” The infinite range of variation between the two ends of this evolutionary process means that many populations are difficult to assign to either a parent species or a new, independent species.
A newer species concept, known as the Phylogenetics Species Concept, attempts to give specific status to any identifiable populations that have a unique evolutionary history and differ collectively in some characteristics from other populations. This system, which places more weight on the evolutionary process and genetic differences between populations, naturally results in a far greater number of recognizable species than the more conservative Biological Species Concept. In truth, however, neither of these widely accepted concepts appears to fully represent the extraordinary complexities of the natural world, and perhaps the most effective current method of species classification is a combination of both systems.
Another method used by taxonomists to deal with the variation within species is the use of “infraspecific” or “subspecific” taxonomy. Many species are not uniform in appearance throughout their distribution, and by assigning subspecies and varietal names to the identifiable populations scientists are able to catalogue and name this variation.
Populations that are approaching species status are typically categorized as subspecies (often written as “ssp.” or “subsp.”), especially when these forms have discrete geographic distributions. For example, in the species Salix reticulata individuals occurring throughout the mountain ranges of the interior of the province with hairy capsules and a strong net-like pattern of venation on the leaves are named S. reticulata ssp. reticulata, while the populations on the Queen Charlotte Islands that have hairless capsules and a weaker net-like venation pattern on the leaves are known as S. reticulata ssp. glabellicarpa. These two subspecies have different geographic ranges and represent evolutionary lines that are fairly well defined, but are similar enough to be classed within the same species, for example…
· Plantae (the plants)
· Marchantiophyta (the liverworts)
· Magnoliopsida (class including the family Magnoliaceae)
· Lilioideae (subclass including the family Liliaceae)
· Pinophyta (the conifers)
· Fagaceae (the beech family)
· Betula (the birch genus)
In two parts
Acacia subg. Phyllodineae (the wattles)
Berberis thunbergii (Japanese barberry)
In three parts
Calystegia sepium subsp. americana (American hedge bindweed)
Summary of classifications
A group of related Plant Families, classified in the order in which they are thought to have developed their differences from a common ancestor.
There are six Superorders in the Dicotyledonae (Magnoliidae, Hamamelidae, Caryophyllidae, Dilleniidae, Rosidae, Asteridae), and four Super-orders in the Monocotyledonae (Alismatidae, Commelinidae, Arecidae, Liliidae)
The names of the Superorders end in -idae
Each Super-order is further divided into several Orders.
The names of the Orders end in -ales
Each Order is divided into Families. These are plants with many botanical features in common, and is the highest classification normally used. At this level, the similarity between plants is often easily recognisable by the layman.
Modern botanical classification assigns a type plant to each Family, which has the particular characteristics which separate this group of plants from others, and names the Family after this plant.
The number of Plant Families varies according to the botanist whose classification you follow. Some botanists recognise only 150 or so families, preferring to classify other similar plants as sub-families, while others recognise nearly 500 plant families. A widely-accepted system is that devised by Cronquist in 1968, which is only slightly revised today.
The names of the Families end in -aceae
The Family may be further divided into a number of sub-families, which group together plants within the Family that have some significant botanical differences.
The names of the Subfamilies end in -oideae
A further division of plants within a Family, based on smaller botanical differences, but still usually comprising many different plants.
The names of the Tribes end in -eae
A further division, based on even smaller botanical differences, often only recognisable to botanists.
The names of the Subtribes end in -inae
This is the part of the plant name that is most familiar, the normal name that you give a plant - Papaver (Poppy), Aquilegia (Columbine), and so on. The plants in a Genus are often easily recognisable as belonging to the same group.
The name of the Genus should be written with a capital letter.
This is the level that defines an individual plant. Often, the name will describe some aspect of the plant - the colour of the flowers, size or shape of the leaves, or it may be named after the place where it was found. Together, the Genus and species name refer to only one plant, and they are used to identify that particular plant. Sometimes, the species is further divided into sub-species that contain plants not quite so distinct that they are classified as Varieties.
The name of the species should be written after the Genus name, in small letters, with no capital letter.
A Variety is a plant that is only slightly different from the species plant, but the differences are not so insignificant as the differences in a form. The Latin is varietas, which is usually abbreviated to var.
The name follows the Genus and species name, with var. before the individual variety name.
A form is a plant within a species that has minor botanical differences, such as the colour of flower or shape of the leaves.
The name follows the Genus and species name, with form (or f.) before the individual variety name.
A Cultivar is a cultivated variety, a particular plant that has arisen either naturally or through deliberate hybridisation, and can be reproduced (vegetative or by seed) to produce more of the same plant.
The name follows the Genus and species name. It is written in the language of the person who described it, and should not be translated. It is either written in single quotation marks or has cv. written in front of the name.
So what is the importance of classification and taxonomy?
It can help identify a new plant. If your unknown plant has the characteristics of a particular Family, then you can narrow the search to find its identity.
It can give you an idea of what the plant looks like. Almost anything in the Asteraceae Family will look like a Daisy. Most members of the Campanulaceae Family have blue flowers in a bell or star shape. Many collections of seed from their natural habitat just give the Family name.
If you know which Plant Family a plant belongs to, it might help you to find the seeds. For instance, members of the Cabbage family (Brassicaceae) have a seedpod that has a thin papery membrane between the two halves (like Honesty), members of the Nettle Family (Lamiaceae) don't have a seed pod, they have four seeds on a pad at the bottom of the open calyx, and members of the old Leguminosae Family all have their seeds in legumes.
Knowing the Plant Family can tell you where the seed pod will be - on the stalk side of the flower (called an Inferior Ovary - such as in Amaryllidaceae, Cannaceae) or in the middle of the flower itself (a Superior Ovary - as in Nyctaginaceae, which includes Mirabilis, Geraniaceae and Iridaceae).
It can often tell you what the seeds will be like - whether they're large or small, and whether there are a lot of them in a seedpod or only one. Members of the Campanulaceae have many small seeds in a capsule, seeds of the Asclepiadaceae are usually flat and oval with long silky hairs and members of the Solanaceae Family have either a berry or a capsule with many seeds.
Knowing the Plant Family can also give you a clue about how to germinate any new seeds you have from other plants in that Family. I know I've had success with many members of the Geranium Family by nicking them and sowing them indoors by the Norman Deno method. That's also worked for many members of the Lily family, but many members of the Iris Family need to be sown outside and take a long time to germinate.
Knowing which Family a plant belongs to can tell you what the seedling looks like. Seeds of all the Monocot families (such as Liliaceae, Iridaceae, other bulbs, grasses and palms) will come up with only one seed leaf. Dicots (most of the other larger plant families) have two seed leaves.
There's a brief introduction to some of the main plant families are as follows:
Apiaceae - Celery or Carrot Family
Apocynaceae - Periwinkle Family
Asteraceae - Daisy Family
Bignoniaceae - Bignonia Family
Boraginaceae - Forget-me-Not Family
Brassicaceae - Cabbage Family
Caesalpiniaceae, Fabaceae, Mimosaceae, Papilionaceae (formerly Leguminosae) - Bean Family
Campanulaceae - Bellflower Family
Caryophyllaceae - Pink Family
Clusiaceae - Hypericum Family
Convolvulaceae - Bindweed Family
Ericaceae - Heath Family
Geraniaceae - Geranium Family
Gesneriaceae - African Violet Family
Hydrophyllaceae - Waterleaf Family
Iridaceae - Iris Family
Lamiaceae - Mint or Nettle Family
Liliaceae - Lily Family
Malvaceae - Mallow Family
Musaceae - Banana Family
Oxalidaceae - Wood Sorrel Family
Papaveraceae - Poppy Family
Plumbaginaceae - Leadwort Family
Polemoniaceae - Phlox Family
Primulaceae - Primrose Family
Ranunculaceae - Buttercup Family
Rosaceae - Rose Family
Rubiaceae - Bedstraw Family
Saxifragaceae - Saxifrage Family
Scrophulariaceae - Figwort Family
Solanaceae - Potato Family
Violaceae - Violet Family
There are several hundred plant families and the botanists are reclassifying them into more every week.