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.

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.

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.

Weeping fig (Ficus benjamina) is an evergreen tree native to Asia and Australia. It is one of the most popular houseplants in the world, known for its elegant, glossy leaves. However, people with allergies should avoid weeping fig, considering that it is a major source of indoor allergens. All parts of the plant are poisonous except the fruits.

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.

The peace lily gets its scientific name Spathiphyllum wallisii from a combination of the two Greek words ‘spath’ and ‘phyl’, which means spoon and leaves, respectively. The large graceful white spathe of the peace lily resembles a white flag, which is an international symbol of truce or peace.

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".

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.

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 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.

Looking like a miniature fairy tale tree, jade plant is one of the world's most popular succulents. Native to southern regions of Africa, Crassula ovata is well adapted to the dry warm air of modern homes. It grows slowly but lives for so long that plants get passed from generation to generation. It is toxic to dogs, cats, and horses, and even mildly toxic to humans.

The golden pothos (Epipremnum aureum) is a popular houseplant that is commonly seen in Australia, Asia, and the West Indies. It goes by many nicknames, including "devil's ivy", because it is so hard to kill and can even grow in low light conditions. Golden pothos has poisonous sap, so it should be kept away from pets and children.

Madagascar dragon tree (Dracaena reflexa var. angustifolia) is an evergreen tree often cultivated as an ornamental or houseplant. It is no wonder why madagascar dragon tree is one of the most popular houseplants - its richly colored, olive-green leaves and thick stems are very aesthetic. Aside from the attractive looks, madagascar dragon tree is said to have good air-purifying qualities (as many indoor plants).

The focal point of a dieffenbachia is the beautiful look and patterns of the foliage, which are often variegated. This plant has showy white blooms, but only flowers in perfect conditions. Use caution, because the dieffenbachia is poisonous; if the sap is ingested it can cause muteness for up to two weeks by numbing the throat and vocal cords.

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.

False christmas cactus gets its name from its flowering season; producing red purple pink or white flowers from fall to winter. Native to a small coastal strip on the east of Brazil this cactus prefers the shade and humidity of jungle conditions. In the wild hummingbirds pollinate the flowers.

Dwarf umbrella tree (*Schefflera arboricola*) is an evergreen, multi-stemmed shrub native to China. It is commonly grown as a houseplant or a garden plant in milder climates for its decorative palmate compound leaves. The leaves contain calcium oxalates, which can damage internal organs when ingested. It shouldn't be confused with the Australian umbrella tree, *Schefflera actinophylla*.

Parlor palm (Chamaedorea elegans) is a palm tree native to Mexico and Guatemala which grows in rainforest environments. Parlor palm is widely cultivated as a houseplant and grows well in light soil out of direct sunlight.

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.