Following is a list of plant families, a few of
their distinguishing characteristics, and some of their more familiar members.
Potato or nightshade family: Solanaceae
Annuals and perennials with star-shaped flowers. Plants in
this family produce alkaloids as a chemical defense against herbivores.
Members include potato, tomato, eggplant, peppers
(including chilis and sweet peppers, but not peppercorns), tomatilla, and cape
gooseberry. Also petunia, salpiglossis, schizanthus, solanum, physalis (Chinese lantern
plant), and nicotiana (tobacco). The toxic alkaloid nicotine is present in several
nicotiana species; it is sometimes used as a powerful insecticide. Poisonous plants in
this family include deadly nightshade (belladonna), jimson weed, and mandrake.
Daisy or sunflower family:
Compositae (also called Asteraceae)
One of the largest families of plants, with about 25,000
species. In many members of this family, what appears to be a single flower is,
botanically speaking, a cluster of flowers made up of many small central disk flowers
surrounded by showy, often sterile ray flowers.
Members include lettuce, chicory, endive, salsify, globe
artichoke, Jerusalem artichoke, and tarragon. Also a huge number of ornamentals, including
daisies of all types, sunflower, dahlia, zinnia, marigold, calendula, cosmos, aster,
gerbera, globe thistle, and artemisia. Many troublesome weeds such as dandelion, thistle,
cocklebur, and ragweed are members of this family.
Carrot family: Umbelliferae (also called Apiaceae)
Many members used for food and flavoring; plants have
deeply cut leaves and strongly-scented foliage. Flowers are borne in flat, terminal
clusters called umbels.
Members include carrot, parsnips, celery, parsley, fennel,
dill, anise, angelica, cumin, coriander, lovage, chervil, and caraway. Also Queen
Annes lace (cow parsley), and hemlock (the poison responsible for the death of
Mustard family: Cruciferae (also called
Includes several common vegetables, some of which are
sharp, bitter, or otherwise strong-tasting. Four-petaled flowers are cross-shaped and
borne in clusters.
Members include mustard, broccoli, cauliflower, cabbage,
Brussels sprouts, kohlrabi, turnips, Chinese cabbage, and kale. Also annual and perennial
flowers including nasturtium, candytuft, alyssum, stocks, and wallflower.
Heath family: Ericaceae
Cool-climate trees and shrubs; some are evergreen, others
are deciduous. The leaves of many species have a leathery texture, and plants in this
family generally prefer part shade and acid soil.
Members include heath, rhododendron, azalea, mountain
laurel, wintergreen, and heathers. Though the family includes the popular fruits
blueberries and cranberries, many other species in the family are poisonous. (Some species
of laurel are very poisonous to sheep, and are known as "lambkill.")
Grass family: Gramineae (or Poaceae)
Annuals and perennials with narrow, ribbon-like leaves,
flowers in spikes, and intercalary meristems. This is the most economically important
plant family. Most of the worlds population depends on a single type of grass as
their staple food.
Family members include wheat, rice, corn, oats, barley,
millet, sorghum, sugar cane, bamboo, and lemon grass. Also lawn grasses such as fescue and
bluegrass. The grass Arundo donax is used to make clarinet reeds.
Lily family: Liliaceae
Many members have narrow, grass-like leaves and showy
flower parts that occur in threes. Some types form scaly bulbs.
Members include asparagus, onion, leek, and garlic. Also
lily, aloe, daylily, liriope (lilyturf), and trillium.
Rose family: Rosaceae
Hardy perennial, shrubs, and trees, many with compound
Members include apple, plum, quince, cherry, plum, peach,
almond, apricot, blackberry, raspberry, and strawberry. Also rose, spiraea, cotoneaster,
potentilla, ladys mantle, pyracantha (firethorn), photinia, and mountain ash.
Pea family: Leguminosae (or Fabaceae)
Includes many important food and forage plants. Plants
have compound leaves; their seeds are borne in pods. Plants in this family form a
relationship with soil-borne, nitrogen-fixing bacteria.
Members include garden peas, chick peas, all sorts of
beans including string beans and soybeans, lentils, alfalfa, and clover. Also sweet pea,
baptisia, acacia, mimosa, wisteria, cassia, lupine.
Citrus or rue family: Rutaceae
Members of this family include trees, shrubs, and a few
perennials; many are evergreen, and most are native to tropical and subtropical climates.
Leaves possess numerous oil glands, and give off a strong aroma when crushed.
Members include lemon, orange, grapefruit, citron,
mandarin, satsuma, tangerine, lime, kumquat, bergamot. Also rue, which is poisonous.
Buttercup family: Ranunculaceae
Most members have cut-leaf foliage and thrive in moist
soils. Some go dormant after flowering.
Members include ranunculus, clematis, globe flower,
delphinium, love-in-a-mist, anemones, hellebores, pulsatilla, and columbine. Some plants
in the family, such as Aconitum (monkshood), are poisonous.
Pink or carnation family: Caryophyllaceae
Short-lived annuals or perennials; prefer full sun and
alkaline soil. Leaves arranged in opposite pattern, petals of flowers often notched, and
stem nodes swollen.
Members include carnation, pinks, sweet William,
snow-in-summer, babys breath, lychnis, and soapwort.
Pumpkin or gourd family: Cucurbitaceae
Quick-growing vines with trumpet-shaped, unisexual flowers
(there are separate male and female flowers), and large, fleshy fruits. Most members have
Members include pumpkin, squash, gourd, zucchini, melon,
cantaloupe, honeydew, cucumber, watermelon, and citron.
Foxglove or figwort family:
Herbaceous plants, flowers bilaterally symmetrical and
borne in spikes or clusters. Most prefer cool temperatures.
Members include foxglove, snapdragon, verbascum, veronica
(speedwell), penstemon, linaria (toad flax), mimulus (monkey flower), and nemesia.
Foxgloves are the source of the powerful heart stimulants digitalis and digoxin.
Mint family: Labiatae (or Lamiaceae)
Herbs, shrubs, and perennials with square stems and
two-lipped flowers. Leaves often aromatic; some members can be invasive.
Members include mint, rosemary, basil, thyme, sage,
oregano, and marjoram. Also lavender, coleus, salvia, stachys (lambs ears), monarda
(bee balm), and patchouli.
Here are some other examples of plant
"relatives" that might surprise you:
Oleaceae: Includes olive, ash, lilac,
jasmine, forsythia, privet.
Convolvulaceae: Includes morning glory, bindweed, and
Rubiaceae: Includes gardenia and coffee.
Which hemlock? The name hemlock is another example of the confusion that
arises when common, rather than botanical, names are used. Many of us know hemlock as a
lovely conifer tree of the genus Tsuga. The hemlock used to poison Socrates, Conium
maculatum, is not a tree, but rather a stout biennial related to carrots and dill.
Most references call it poison-hemlock to distinguish it from the conifer.
All parts of the poison-hemlock plant are
poisonous, but the immature fruits and seeds are the most lethal. A decoction made from
these plant parts was used by ancient Greeks to carry out their form of the death penalty.
Poison-hemlock is widely naturalized throughout North
America, so always make sure you positively identify any wild plant before tasting it!