Paulowniaceae are a family of flowering plants within the Lamiales. They are a monophyletic and monogeneric family of trees with currently 7 confirmed species. They were formerly placed within Scrophulariaceae sensu lato, or as a segregate of the Bignoniaceae.
Orobanche, commonly known as broomrape, is a genus of over 200 species of small parasitic herbaceous plants, mostly native to the temperate Northern Hemisphere. It is the type genus of the broomrape family Orobanchaceae.
Orobanchaceae, the broomrapes, is a family of mostly parasitic plants of the order Lamiales, with about 90 genera and more than 2000 species. Many of these genera were formerly included in the family Scrophulariaceae sensu lato. With its new circumscription, Orobanchaceae forms a distinct, monophyletic family. From a phylogenetic perspective, it is defined as the largest crown clade containing Orobanche major and relatives, but neither Paulownia tomentosa nor Phryma leptostachya nor Mazus japonicus.
Rehmannia is a genus of seven species of flowering plants in the order Lamiales and family Orobanchaceae, endemic to China. It has been placed as the only member of the monotypic tribe Rehmannieae, but molecular phylogenetic studies suggest that it forms a clade with Triaenophora. Contrary to the immense majority of the taxa of Orobanchaceae, Rehmannia is not parasitic.
The Rafflesiaceae are a family of rare parasitic plants comprising 36 species in 3 genera found in the tropical forests of east and southeast Asia, including Rafflesia arnoldii, which has the largest flowers of all plants. The plants are endoparasites of vines in the genus Tetrastigma (Vitaceae) and lack stems, leaves, roots, and any photosynthetic tissue. They rely entirely on their host plants for both water and nutrients, and only then emerge as flowers from the roots or lower stems of the host plants.
In 1909, the entomologist Carlo Emery noted that social parasites among insects tend to be parasites of species or genera to which they are closely related. Over time, this pattern has been recognized in many additional cases, and generalized to what is now known as Emery's rule. The pattern is best known for various taxa of Hymenoptera. For example, the social wasp Dolichovespula adulterina parasitizes other members of its genus such as Dolichovespula norwegica and Dolichovespula arenaria. Emery's rule is also applicable to members of other kingdoms such as fungi, red algae, and mistletoe. The significance and general relevance of this pattern are still a matter of some debate, as a great many exceptions exist, though a common explanation for the phenomenon when it occurs is that the parasites may have started as facultative parasites within the host species itself, but later became reproductively isolated and split off from the ancestral species, a form of sympatric speciation.
A parasitic plant is a plant that derives some or all of its nutritional requirement from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants have modified roots, called haustoria, which penetrate the host plant, connecting them to the conductive system – either the xylem, the 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 Orobanche connect only to the phloem of the host (phloem-feeding). This provides them with the ability to extract water and nutrients from the host. Parasitic plants are classified depending as to the location where the parasitic plant latches onto the host and the amount of nutrients it requires. Some parasitic plants are able to locate their host plants by detecting chemicals in the air or soil given off by host shoots or roots, respectively. About 4,500 species of parasitic plant in approximately 20 families of flowering plants are known.
Orobanche aegyptiaca, the Egyptian broomrape, is a plant which is an obligate holoparasite from the family Orobanchaceae with a complex lifecycle. This parasite is most common in the Middle East and has a wide host range including many economically important crops.
Lindenbergia is a genus of herbaceous plants in the order Lamiales and in the broomrape family Orobanchaceae. It is one of the few genera of the family which are not parasitic. It contains about 15 species found from northeast Africa across Asia to the Philippines, and is most abundant in India.
Cytinus is a genus of parasitic flowering plants. Species in this genus do not produce chlorophyll, but rely fully on its host plant. Cytinus usually parasitizes Cistus and Halimium, two genera of plants in the family Cistaceae. It has also been found on Ptilostemon chamaepeuce.
Orobanche pinorum is a species of broomrape known by the common name conifer broomrape. It is native to the forests of western North America, where it is a parasite growing attached to the roots of other plants, usually Holodiscus species. This plant has an erect stem with a wide, thickened base and slender top growing 10–30 centimetres (3.9–11.8 in) tall. As a parasite taking its nutrients from a host plant, it lacks leaves and chlorophyll and is brownish or yellowish in color. The inflorescence is a dense, spreading array of purple-tinged yellowish flowers 1–2 centimetres (0.39–0.79 in) long.
Orobanche rapum-genistae, the greater broomrape, is a plant species in the genus Orobanche. It is a parasitic plant, native to Europe, growing on the roots of plants in the bean family, usually common broom or European gorse.
Desert broomrape can refer to several parasitic plants in the family Orobanchaceae, including:
Boschniakia rossica, commonly known as the northern groundcone, is a holoparasitic plant that lives in the northern latitudes of the northern hemisphere. In the Pacific Northwest Temperate Rainforest, it does not grow south of Prince of Wales Island, beyond that boundary is the Vancouver groundcone habitat. It does not contain chlorophyll, so it must be parasitic to obtain nutrients. It specializes on Alnus species, but can parasitize off of other trees and shrubs such as on Betula (birch), Salix (willow), Vaccinium (blueberry), Picea (spruce), and Chamaedaphne. This organism is likely to be found at mid elevations alongside rivers and streams, where moisture is abundant. This species propagates itself through water flow. In some places bears are known to have eaten the starchy roots, or tubers, of this plant.
Aeginetia indica, commonly known as Indian broomrape or forest ghost flower, is a holoparasitic herb or root parasite of the plant family Orobanchaceae. It grows in moist deciduous and semi-evergreen forests of tropical and subtropical Asia and New Guinea. It parasitises plants of the families Cannaceae, Commelinaceae, Cyperaceae, Juncaceae, Poaceae, and Zingiberaceae.
Orobanche ludoviciana, the Louisiana broomrape or prairie broom-rape, is a species of plant in the family Orobanchaceae. It was first described and named by Thomas Nuttall in 1818.
Orobanche hederae, the ivy broomrape, is, like other members of the genus Orobanche, a parasitic plant without chlorophyll, and thus totally dependent on its host, which is ivy. It grows to 60 cm (2 ft), with stems in shades of brown and purple, sometimes yellow. The flowers are 10–22 mm (0.4–0.9 in) long, cream in colour with reddish-purple veins.
Cospeciation is a form of coevolution in which the speciation of one species dictates speciation of another species and is most commonly studied in host-parasite relationships. In the case of a host-parasite relationship, if two hosts of the same species get within close proximity of each other, parasites of the same species from each host are able to move between individuals and mate with the parasites on the other host. However, if a speciation event occurs in the host species, the parasites will no longer be able to "cross over" because the two new host species no longer mate and, if the speciation event is due to a geographic separation, it is very unlikely the two hosts will interact at all with each other. The lack of proximity between the hosts ultimately prevents the populations of parasites from interacting and mating. This can ultimately lead to speciation within the parasite.
Orobanche reticulata is a species of broomrape known by the common name thistle broomrape. It is a parasitic plant whose host is normally the creeping thistle. It is native to the lowlands of Western Europe and Central Asia, but in the United Kingdom it is a rare and protected plant, growing only in Yorkshire, on grassland sites such as Quarry Moor.
Triaenophora is a genus of flowering plants native to Temperate Asia. Its family placement is not fully settled, as of March 2022: it may be placed in Orobanchaceae or Plantaginaceae.
