Finger millet is an annual herbaceous plant widely grown as a cereal crop in the arid and semiarid areas in Africa and Asia. It is a tetraploid and self-pollinating species probably evolved from its wild relative Eleusine africana.
Buddleja is a genus comprising over 140 species of flowering plants endemic to Asia, Africa, and the Americas. The generic name bestowed by Linnaeus posthumously honoured the Reverend Adam Buddle (1662–1715), an English botanist and rector, at the suggestion of William Houstoun. Houstoun sent the first plants to become known to science as buddleja to England from the Caribbean about 15 years after Buddle's death. Buddleja species, especially Buddleja davidii and interspecific hybrids, are commonly known as butterfly bushes and are frequently cultivated as garden shrubs. Buddleja davidii has become an invasive species in both Europe and North America.
Carduus nutans is a biennial plant in the daisy and sunflower family Asteraceae with the common names musk thistle, nodding thistle, and nodding plumeless thistle. It is native to regions of Europe, Central Asia, and North Africa, where it is a scattered pasture plant. The musk thistle has been declared as invasive in North America, Australia, New Zealand, and South Africa.
Rhinanthus minor, known as yellow rattle, is a herbaceous wildflower in the genus Rhinanthus in the family Orobanchaceae. It has circumpolar distribution in Europe, Russia, western Asia, and northern North America. An annual plant, yellow rattle grows up to 10–50 centimetres (3.9–19.7 in) tall, with upright stems and opposite, simple leaves. The fruit is a dry capsule, with loose, rattling seeds.
Imperata cylindrica is a species of perennial rhizomatous grass native to tropical and subtropical Asia, Micronesia, Melanesia, Australia, Africa, and Southern Europe. It has also been introduced to Latin America, the Caribbean, and the Southeastern United States. It is a highly flammable pyrophyte, and can spread rapidly by colonizing disturbed areas and encouraging more frequent wildfires.
Striga, commonly known as witchweed, is a genus of parasitic plants that occur naturally in parts of Africa, Asia, and Australia. It is currently classified in the family Orobanchaceae, although older classifications place it in the Scrophulariaceae. Some species are serious pathogens of cereal crops, with the greatest effects being in savanna agriculture in Africa. It also causes considerable crop losses in other regions, including other tropical and subtropical crops in its native range and in the Americas. The generic name derives from Latin strī̆ga, "witch".
Tradescantia fluminensis is a species of spiderwort native to South America. It is one of several plants known by the common name wandering Jew. It is also known as small-leaf spiderwort, river spiderwort, inch plant, speedy Henry, wandering willie and wandering trad.
Desmodium is a genus of plants in the legume family Fabaceae, sometimes called tick-trefoil, tick clover, hitch hikers or beggar lice. There are dozens of species and the delimitation of the genus has shifted much over time. Species are distributed widely – from Quebec to northern Argentina in the Americas, across northern and southern tropical Africa, in the southern Arabian Peninsula, in Myanmar and Thailand, New Guinea, and northern and eastern Australia.
Centella asiatica, commonly known as Indian pennywort, Asiatic pennywort, spadeleaf, coinwort or gotu kola, is a herbaceous, perennial plant in the flowering plant family Apiaceae. It is native to tropical regions of Africa, Asia, Australia, and islands in the western Pacific Ocean. It is consumed as a culinary vegetable and is used in traditional medicine.
The soil seed bank is the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lake. The first scientific paper on the subject was published in 1882 and reported on the occurrence of seeds at different soil depths. Weed seed banks have been studied intensely in agricultural science because of their important economic impacts; other fields interested in soil seed banks include forest regeneration and restoration ecology.
A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called the haustorium, which penetrates the host plant, connecting them to the host vasculature – either the xylem, phloem, or both. For example, plants like Striga or Rhinanthus connect only to the xylem, via xylem bridges (xylem-feeding). Alternately, plants like Cuscuta and some members of Orobanche connect to both the xylem and phloem of the host. This provides them with the ability to extract resources from the host. These resources can include water, nitrogen, carbon and/or sugars. Parasitic plants are classified depending on the location where the parasitic plant latches onto the host, the amount of nutrients it requires, and their photosynthetic capability. Some parasitic plants can locate their host plants by detecting volatile chemicals in the air or soil given off by host shoots or roots, respectively. About 4,500 species of parasitic plants in approximately 20 families of flowering plants are known.
Asparagus asparagoides, commonly known as bridal creeper, bridal-veil creeper, gnarboola, smilax or smilax asparagus, is a herbaceous climbing plant of the family Asparagaceae native to eastern and southern Africa. Sometimes grown as an ornamental plant, it has become a serious environmental weed in Australia and New Zealand.
Lantana camara is a species of flowering plant within the verbena family (Verbenaceae), native to the American tropics. It is a very adaptable species, which can inhabit a wide variety of ecosystems; once it has been introduced into a habitat it spreads rapidly; between 45ºN and 45ºS and less than 1,400 metres in altitude.
A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals. Plants with characteristics that make them hazardous, aesthetically unappealing, difficult to control in managed environments, or otherwise unwanted in farm land, orchards, gardens, lawns, parks, recreational spaces, residential and industrial areas, may all be considered weeds. The concept of weeds is particularly significant in agriculture, where the presence of weeds in fields used to grow crops may cause major losses in yields. Invasive species, plants introduced to an environment where their presence negatively impacts the overall functioning and biodiversity of the ecosystem, may also sometimes be considered weeds.
Cytisus multiflorus is a species of legume known by the common names white broom, white spanishbroom and Portuguese broom.
Striga hermonthica, commonly known as purple witchweed or giant witchweed, is a hemiparasitic plant that belongs to the family Orobanchaceae. It is devastating to major crops such as sorghum and rice. In sub-Saharan Africa, apart from sorghum and rice, it also infests maize, pearl millet, and sugar cane.
Rhamphicarpa fistulosa is a flowering plant species in the family Orobanchaceae - and the genus Rhamphicarpa. The plant is pale-green but can turn reddish towards maturity. It has needle-like leaves and white flowers with long corolla tubes. The flowers only open after sunset and are supposedly pollinated by night moths. The plant has a broad distribution in Africa and can also be found in New Guinea and northern Australia.
Crassula ovata, commonly known as jade plant, lucky plant, money plant or money tree, is a succulent plant with small pink or white flowers that is native to the KwaZulu-Natal and Eastern Cape provinces of South Africa, and Mozambique; it is common as a houseplant worldwide. Much of its popularity stems from the low levels of care needed; the jade plant requires little water and can survive in most indoor conditions. It is sometimes referred to as the money tree; however, Pachira aquatica also has this nickname.
Desmodium intortum, known as greenleaf desmodium and also as beggarlice along with other members of its genus, is a species of flowering plant in the genus Desmodium, native to Mexico, Central America, northern South America, the Galápagos, Haiti and Jamaica. A nitrogen-fixing fodder crop, it has been introduced to the rest of the world's tropics, including Africa, India, Australia, New Guinea and Taiwan
Meadow knapweed, also known as hybrid knapweed or protean knapweed, is a fertile hybrid between black knapweed and brown knapweed. The taxonomic status of the species is uncertain, and meadow knapweed has been variously described as different species.
