Annual ragweed (Ambrosia artemisiifolia) is one of the most notorious weeds in the world. It is an annual herbaceous plant with highly allergenic pollen and a very vigorous spread. Annual ragweed is a very competitive species, which is why its presence in cultivated plants is highly undesirable.

Greater celandine (Chelidonium majus) is a plant species with distinctive golden-yellow flowers. It has been cultivated since the era of Pliny the Elder, in the first century. The greater celandine is actually a part of the poppy family, and like other species in that genetic family, it is well known for its recognizable, bright blooms. The yellow latex inside is equally recognizable, but is highly toxic if consumed.

Common yarrow is a wildflower that has feathery leaves and flowers in white, yellow or pink. In China, the plant is considered to be good luck while for some time in Scotland it was believed to have magical properties. It has been brewed into beer, tea, and liquors, but it has low toxicity. Do not consume in large quantities. Common yarrow's bitter leaves are toxic to pets and horses. Other livestock can eat it, though it gives cow milk an unpleasant flavor.

English ivy is the most common climber of European forests. It is a perennial woody vine with evergreen, dark, shiny lobed leaves. It utilizes aerial rootlets to attach to the tree bark with exceptional strength, helping the english ivy creep more than 15 m up a tree. Hedera helix also grows as a forest groundcover and is invasive outside its native range.

Florist kalanchoe (Kalanchoe blossfeldiana) originates from Madagascar and has been a popular houseplant since the 1930s. Unlike most other succulents that are grown for their interesting leaves, Kalanchoe blossfeldiana is valued for the colorful flowerheads it produces in autumn and winter. This is the reason it is commonly gifted during holidays, earning it another name - Christmas kalanchoe. It is toxic to pets.

While the black locust may have a bad reputation in many areas of the US due to its opportunistic and rapid growth, there are benefits to this tree. The black locust is an important food source for honey bees and is a good choice for windbreaks since it grows so quickly (91 to 122 cm per year). Its wood also resists rot, so it is used in fenceposts. The plant is highly toxic, though, and should never be consumed.

Portulaca oleracea, colloquially known as common purslane, is an annual succulent species with reddish stems and tiny yellow, five-petal flowers. It is used for culinary purposes in various parts of the world, most often raw, in salads. Common purslane is also a good companion plant for crops that thrive in moist soils.

Nerium oleander, colloquially known as oleander, is a shrub or a small tree, known for its majestic pink five-lobed flowers and deep green lanceolate leaves. Oleander is one of the most poisonous popular decorative garden plants, so it is advised to keep small children and pets away from it.

Although its berries look juicy and tempting, the fruits and the root of pokeweed are toxic and should not be eaten. Pokeweed is considered a pest species by farmers but is nevertheless often grown as an ornamental plant. Its berries can be made into pokeberry ink as well.

Common bean is one of the most widely produced cash crops in the world, with 23.6 million tons grown in 2016. China is the largest producer of common bean, accounting for 79% of the market share. While common bean is known as a staple food source, the leaves can be used to trap bedbugs and the beans are widely used in a type of fortune-telling called "pharmancy".

Corn plant (Dracaena fragrans) is an evergreen, slow-growing perennial shrub native to tropical Africa. Also, it is a classic houseplant, grown in Europe since the 1800s. Its glossy green foliage that resembles corn leaves grow on top of a thick cane, which is why the plant is sometimes called “false palm tree.”

The common daisy produces iconic flowers that are seen in European and American folklore dating back centuries. It is often a representation of childlike innocence. The plant is edible and can be used in small quantities in salads, sandwiches, soups, or tea. However, it can also become toxic and cause digestive problems if eaten in quantity.

Shepherd's purse (Capsella bursa-pastoris) is native to Eastern Europe and Asia minor. Having spread and become naturalized around the world, this herbaceous plant is typically considered a weed. Shepherd's purse is considered a "protocarnivore" because it attracts nematodes (small worms in the soil) and poisons them with its seeds. By eliminating nematodes, this plant enriches the surrounding soil.

Ficus carica, colloquially known as the common fig, is a deciduous small tree or shrub widely known for its sweet, chewy fruits. This shrubby plant has a very, very long cultivation history. The earliest evidence of its cultivation was found in the Jordan Valley and go all the way back to the tenth millennium BC.

Maize (Zea mays) is a well known domesticated cereal grain first domesticated in Mexico. In much of the world it is also called corn. Worldwide cultivation of maize surpasses other prominent grains like wheat and rice. Maize must be planted in the spring due to its intolerance for cold weather.

The norway maple is a tree species native to Europe and West Asia. It is 20 to 30 m tall and has bright green, lobed leaves which turn yellow or red in the autumn. Introduced as an ornamental shade tree in the United States, it is now considered invasive. Outside its northern range, it can be short-lived and susceptible to disease and damage.

The pepper are commonly used for cooking in places such as the Southern U.S. and Central America. Most are moderately spicy, though because there are so many variants, the spice level can vary dramatically. Cayenne powder is also a popular seasoning product made from pepper plants.

Ground ivy (Glechoma hederacea) is a perennial evergreen trailing plant, often found in grasslands and woodlands. Saxon peoples once spread the plant, but it has become invasive in some parts of the world now. The fast-growing ground ivy can be toxic to horses but generally cannot harm other animals or humans.

Common lilac is a shrub native to the Balkan Peninsula that blooms with a fragrant blossom. It grows on rocky terrain and has a suckering habit. The blossoms are used to flavor honey, sugars, food, and other delights and farmed for its fragrant flowers in the spring.

Field maple (Acer campestre) is a deciduous flowering plant species native to continental Europe and western Asia. Field maple grows in plains, hills and along rivers. This species is grown as an ornamental tree in parks and gardens. Its wood is used to make flooring and musical instruments.