Paulowniaceae are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s within the

Lamiales The order Lamiales (also known as the mint order) are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided into about 25 families. These families include Acanthaceae, Bi ...

. They are a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

and

monogeneric In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family of trees with currently 7 confirmed species. They were formerly placed within

Scrophulariaceae The Scrophulariaceae are a family of flowering plants, commonly known as the figwort family. The plants are annual and perennial herbs, as well as shrubs. Flowers have bilateral (zygomorphic) or rarely radial (actinomorphic) symmetry. The Scr ...

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'', or as a segregate of the

Bignoniaceae Bignoniaceae is a family of flowering plants in the order Lamiales commonly known as the bignonias or trumpetvines.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: ...

. The Paulowniaceae are now resolved as a distinct separate family consisting of the genus ''

Paulownia ''Paulownia'' ( ) is a genus of seven to 17 species of hardwood tree (depending on taxonomic authority) in the family Paulowniaceae, the order Lamiales. They are present in much of China, south to northern Laos and Vietnam and are long cultivat ...

''. They are

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

trees with large heart shaped leaves and long

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s of white-purple to lavender flowers native to eastern Asia. The most widely distributed and recognized species is ''

Paulownia tomentosa ''Paulownia tomentosa'', common names princess tree, empress tree, or foxglove-tree, is a deciduous hardwood tree in the family Paulowniaceae, native to central and western China. It is an extremely fast-growing tree with seeds that disperse rea ...

'' with common names such as Princess tree, Empress tree, Kiri tree, Foxglove tree, and Phoenix tree.

Taxonomy

There are 7 confirmed species of Paulownia with potentially more as

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

, or mismatched

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

species. * ''

Paulownia fargesii ''Paulownia'' ( ) is a genus of seven to 17 species of hardwood tree (depending on taxonomic authority) in the family Paulowniaceae, the order Lamiales. They are present in much of China, south to northern Laos and Vietnam and are long cultiva ...

'' * ''

Paulownia fortunei ''Paulownia fortunei'' commonly called the dragontree, dragon tree or Fortune's empress tree, is a deciduous tree in the family Paulowniaceae, native to southeastern China (including Taiwan), Laos and Vietnam. It is an extremely fast-growing tre ...

'' * '' Paulownia x taiwaniana'' * '' Paulownia catalpafolia'' * ''

Paulownia elongata ''Paulownia elongata'' is a species of tree in the family Paulowniaceae, native to Asia. The plant's leaves are very large and pubescent ('fuzzy—hairy'). This species can withstand a very wide range of environmental conditions. It does not g ...

'' * ''

'' * '' Paulownia coreana'' (''Paulownia tomentosa var. coreana)'' * ''

Paulownia kawakamii ''Paulownia kawakamii'', commonly known as the sapphire dragon tree, is a tree species in the family Paulowniaceae. The tree is native to Taiwan, eastern China, and Japan. It is deciduous and bears many large violet flowers in early spring b ...

Phylogeny

Paulowniaceae is sister to the

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 (e.g., ''Pedicularis'', ''Rhinanthus'', ''Striga'') were formerly included in the ...

, a primarily hemi-

holoparasitic 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 ...

plant family, except for the clade of herbaceous genera ''

Lindenbergia ''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 A ...

'', ''

Rehmannia ''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 t ...

'', and ''

Triaenophora ''Triaenophora'' is a genus of flowering plants native to Temperate Asia. Its family placement is not fully settled, : it may be placed in Orobanchaceae or Plantaginaceae. Taxonomy The genus ''Triaenophora'' was first erected by Hans Solereder ...

''. This clade of non-parasitic plants within Orobanchaceae are most closely related to ''Paulownia.'' Sister to the Orobanchaceae-Paulowniaceae clade is

Phrymaceae Phrymaceae, also known as the lopseed family, is a small family of flowering plants in the order Lamiales.Peter F. Stevens (2001 onwards). "Phrymaceae" At: Angiosperm Phylogeny Website. At: Botanical Databases At: Missouri Botanical Garden Websit ...

. Phrymaceae are mostly herbaceous plants with a widespread distribution. ,

The Plant List The Plant List was a list of botanical names of species of plants created by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden and launched in 2010. It was intended to be a comprehensive record of all known names of plant species ...

accepted four genera in the family. However of these four genera currently only ''Paulownia'' is a recognized member of Paulowniaceae. * ''

'' * '' Brandisia'' is settled in the Orobanchaceae as sister to the '' Pterygiella'' due to molecular data from 9 chloroplast markers and samples from 6 of the 11 ''Brandisia'' species. They are a mostly shrublike family with hemi-parasitic characters that sometimes grow like climbing vines. Morphological similarities between ''Bradisia'' and ''Pterygiella'', such as eglandular hairs on their capsules, reticulate seeds, and similar shaped tricolpate pollen, confirm their close relationship. * '' Wightia'' is now tentatively positioned as a sister group to Phrymaceae due to many morphological similarities as well as support by chloroplast and mitochondrial DNA analysis. They are a small genus of two species in Southeast Asia, that can grow as a shrub or tree, or as hemiepiphetic pseudo-vine. There are still morphological characters as well as nuclear genome data to support ''Wightia'' as sister to ''Paulownia'' leading it to be of proposed hybrid origin from Phrymaceae and Paulowniaceae. This theory, based on chloroplast genome evidence, would explain its morphological similarities to both families. However the conflicts between the chloroplast, mitochondrial, and nuclear phylogenetic data make it unclear. If these were tested further and proven to be correct it should place ''Wightia'' as a new family Wightiaceae. Though according to Liu et al., 2019, ''Wightia'' should already be its own distinct family as it is highly unlikely that any new study would provide more questionable data against this theory. * '' Shiuyinghua'' is an accepted genus on The Plant List and is listed under Paulowniaceae, but there is no updated published work on the phylogeny of the genus or its species '' Shiuyinghua silvestrii''. ''Shiuyinghua'' has a history of being placed under the name ''Catalpa silvestrii'' in Bignoniaceae due to its leaf shape, but then as '' Paulownia silvestrii'' in the clade Paulownieae in Scrophulariaceae due to similarities in lateral and terminal inflorescences, and in the five-lobed calyx structure. In 1959 ''S. silvestrii'' was believed to be a distinct species within the Paulownieae tribe due to the overall flower bud shape being significantly different from all other members of ''Paulownia''. The genus was named after Dr. Shiu-ying Hu of Harvard University's Arnold Arboretum. Since then there has been no more evidence or discussion on its placement, nor any available molecular data on a species under the name ''Shiuyinghua silvestrii'' or ''Paulownia silvestrii''.

References

{{Taxonbar, from=Q1896257 Lamiales families Taxa named by Takenoshin Nakai