How to Identify Six Plant Families Using their Flowers
The plant kingdom is composed of a wide variety of plant species. It can be subdivided into vascular and non-vascular plants. Vascular plants are characterized by having specialized tissues (xylem and phloem) to transport food and minerals, unlike non-vascular plants. Plants can further be classified as angiosperms and gymnosperms. Angiosperms are the largest group of plants on earth and are characterized by having flowers at some stage in their lives. Angiosperms or flowering plants can be subdivided into monocots and dicots, with monocots having a single seed leaf and dicots having two seed leaves.
Most flowering plants that are members of the same family have similar characteristics for identification. Some of the most common plant families are mint family, parsley family, mustard family, pea family, lily family, grass family, rose family and aster family. It is very important to be able to identify the family that a plant belongs to. This is because related plants often have similar uses.
One of the very obvious parts of any flowering plant is its flower. As such, the flower is an important element that can be used to group plants into their various families. However, to be able to use the flower to effectively group plants into their various families, we need to first get acquainted with the major parts of a flower. We also need to familiarize ourselves with some terms like regular flowers, irregular flowers, composite flowers, compound umbel, unisexual flowers and bisexual flowers.
Parts of a Flower
For the purpose of our discussion, we will only focus on the five major parts of the flower which are the sepals, petals, stamen, pistil and ovary.
Petal: The parts of a flower that are often conspicuously colored.
Pistil: The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma. The mature ovary is a fruit, and the mature ovule is a seed. The pistil is the female part of the flower.
Regular, Irregular, Composite, Unisexual and Bisexual Flowers
A regular flower is of radial symmetry and hence in whatever plane you cut through the flower in a longitudinal manner, you will always obtain a half flower. An irregular flower differs in that it has bilateral symmetry. You can only cut this type of flower down in one plane in order to obtain a half flower.
Composite flowers are made up of inflorescences. Inflorescences are clusters of little flowers that seem like one big flower, but actually are many smaller flowers clustered together. Many composite flowers have two types of flowers. One type of flower is the ray part and the second type of flower are small tube-like flowers that are clustered together making a disc shape. The ray flowers surround the disc-shaped flowers.
A unisexual flower may either contain a stamen or a pistil. However, a bisexual flower contains both the stamen and the pistil.
An Umbel is a flower head in which all the flower stalks are of the same length so that the flower head is rounded like an umbrella. A Compound Umbel is an umbel where each stalk of the umbel produces a smaller umbel of flowers.
Now that we have a good understanding of the various parts and features of a flower, we would go ahead and use what we have learned to group some plants into their families.
The main characteristic of plants in the Parsley Family is that they have "compound umbels" with one umbrella-like umbel supporting several smaller umbels. The carrot is a popular example of a plant that belongs to this family.
Plants in the Mustard Family are mostly weedy annuals with small flowers that have four petals and six stamens. Four of the six stamens are tall and the other two are short. They possess four sepals and one pistil. They also have regular flowers which are bisexual. Some popular examples of plants in this family are broccoli, cabbage, and cauliflower.
Plants in the Pea Family are characterized by having irregular flowers. They also have a large "banner petal", two "wing petal" and a "keel". Some important agricultural and food plants such as soybean, beans, and pea belong to this family.
Lily are showy "monocot" flowers with floral parts in multiples of three. They have what appears at first to be six petals but it is in actuality three petals and three sepals that are identical in size and in color. They also have six stamens and three-parted pistil. They include hyacinths, tulips, and onions.
Plants in the Rose Family usually have five petals and sepals with numerous stamens. Several economically important products come from the Rose Family, including many edible fruits (such as apples, pears, quinces, cherries, peaches, raspberries, and strawberries), and ornamental trees and shrubs (such as roses, meadow-sweets, firethorns, and hawthorns).
The key feature of plants in the Aster Family is composite flowers with multiple small flowers attached to a center disc. Each of these composite flowers is actually a five-petal flower. They also have numerous stamens. The Aster Family are an economically important family, providing products such as cooking oils, lettuce, sunflower seeds, artichokes, sweetening agents, coffee substitutes and herbal teas.
So what is the essence of knowing these plant families? First and foremost there are more than three thousand species of mustards around the world and they are all edible. So let's say you find yourself lost in the forest with no food, and you are at the brink of death. You can use your little knowledge of botany to ensure your survival. You know mustards have four petals and six stamens with four being tall and two being short. You can therefore be on the lookout for flowers with these features to consume.