Many years ago, I noticed that the leaf of a tomato variety I hadn’t planted previously looked like a potato leaf. How could that be? So began my deeper interest in the plant world beyond just the pleasure of planting and harvesting but learning who’s related to whom.

There aren’t any Smith or Jones families in the plant family tree. The names are far more complicated. The Rosaceae, Solanaceae, Asteraceae and Brassicaseae families have more aunts, uncles and cousins that far outnumbers most family trees.

Having even a thimble-full of knowledge can be useful. It can be something as simple as recognizing when an enthusiastic customer has inadvertently replaced a plant tag in the wrong container at a garden center. More importantly, knowing the family will help you understand the importance of crop rotation. If you discover you have a soil fungus affecting a garden crop and the following year plant a species of the same family to that spot, you will have the same problem.

The characteristics the family members have in common are leaf placement, flower formation, fruits and seeds. Are the leaves arranged opposite of each other, or alternately, in a whorled or rosette pattern? Do the flowers have the same number of petals; do the flowers have the same number of petals but different numbers of stamens? The bottom line is that plants that have some feature in common are probably related.

The Rosaceae family provides us with more than a bouquet of sweet smelling roses. It has been said that the Rosaceae family makes life worth living as it provides us with apples, pears, plums, peaches, strawberries and raspberries. The family also includes the ornamentals of the crab apple and the mountain ash. Cotoneaster, geum and potentilla are also members of this family. Most members of the Rosaceae have rather flat flowers of five petals that have wavy margins and 10 to many stamens. This applies to the original varieties of the plant and not the hybrid varieties developed for bigger and better features.

The Solanaceae family does include the potato and tomato in addition to eggplant, peppers and tobacco. It is probably the leading horticultural groups of plants under world-wide cultivation. Although the family includes mainly vegetables, petunias and nicotiana are two flowers that are related. A common characteristic would be that the fruit is portioned into two or four seed producing cavities and may be dry or a fleshy berry. The family is often referred to as the nightshade family of which some members, generally those in the wild, are considered poisonous. This includes the invasive garden weed known as nightshade.

Become familiar with another member of the nightshade family that is extremely poisonous, the water hemlock, usually found on ditch banks, and has been mistaken for wild celery. Always use extra protection when eradicating it.

Sometimes family names get changed as in the case of the Compositae family now being classified as the Asteraceae family. For all practical purposes, you could call it the sneezy family as it contains many aunts, uncles and cousins that aggravate allergies. The common characteristic is that the plants have heads composed of many florets. The family would include asters, daisy, dandelion, goldenrod, marigold, ragweed, sunflower, thistle and zinnia. Lettuces, artichoke, endive, yarrow, Russian knapweed, many varieties of artemisea including sagebrush, chamomile and pearly everlasting share branches of this 20,000 plus species family tree

Brassicaceae formerly Cruciferae, the mustard family, is probably the family we are most familiar with and may not know it. The family includes many of the vegetables that grace our dinner table. Cabbage, cauliflower, broccoli, mustard, Brussels sprouts, kale, kohlrabi, turnip and radish all share a family relationship. Candytuft, basket-of-gold, sweet alyssum, flowering garden favorites also share the family tree.

Plants in the mustard family usually have simple leaves arranged alternately and many are peppery-flavored. The flowers are in the form of a cross with four petals and four sepals with the flower color usually being white, yellow or lavender.

Cooler, indoor weather is heading our way. You might start a “to do” list of subjects you want to know more about with one being to investigate who might be an aunt, uncle or cousin to your favorite plant. If you want to dig deeper, check out “Botany in a Day — The Patterns Method of Plant Identification” by Thomas Elpel. You won’t learn it all in one day but you will get a good start in putting two and two together.

— Reporter: douville@bendbroadband.com