A plant family is a collection of closely related plants that share a set of common characteristics and which evolved from a common ancestor. A plant’s ‘family’ is part of its taxonomy (scientific name). Several taxonomic ranking systems are in use. One of the simplest and probably the most well known is:

  1. Kingdom
  2. Phylum
  3. Class
  4. Order
  5. Family
  6. Genus
  7. Species

Why it’s helpful to know what family a plant belongs to

Knowing which family a plant comes from can tell you all sorts of useful information including:

  • What the plant and its seedlings look like
  • The general growing conditions for the plant
  • What nutrients the plant is likely to use most heavily
  • The pests and diseases the plant is most susceptible to
  • What other plants might cross-pollinate with the plant in question

Knowing a plant’s taxonomic family can thus help you protect it from common pests and diseases, provide the right nutrients for it, save its seeds for replanting in subsequent seasons, use it in a crop rotation system and use it as a companion plant. If you find a seedling or older plant in your garden that you didn’t plant or don’t remember planting, you can also use a knowledge of plant families to help you figure out what the plant is. You won’t be able to figure out its exact species but you can narrow things down.

How to identify the family a plant belongs to

You can learn to identify a plant’s family based on a variety of visual clues. This is because plants from the same family share many visible characteristics. As an example, plants from the mustard family have similar flowers with four petals and six stamens and they’re usually yellow, though some are white.

If you do a Google search, you’ll find plenty of resources to help you with this. Here’s an example of a good resource for identifying wildflowers by their families. Your local library will probably have a few volumes on the subject too.

It can take quite some time to become proficient at this, however, and if you’re like most home gardeners, you’ll probably find that the easiest way to identify a plant’s family is to look it up. You can google individual plant species (or varieties) or you can choose a reference that lists most of the plants you grow (or all of them if you’re lucky).

As it’s usually most important to know the plant families that edible species belong to, I created a free dictionary-style ebook that lists the most common edible plants grouped by their plant families. If it’s missing your favourite edible plant, let me know and I’ll update it.

K. M. Wade

K. M. Wade is a multi-genre and freelance writer, gardener and scientist

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