Ceratophyllaceae is a cosmopolitan family of flowering plants including one living genus commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions. It is the only extant family in the order Ceratophyllales. Species are commonly called coontails or hornworts, although hornwort is also used for unrelated plants of the division Anthocerotophyta.
Hypericaceae is a plant family in the order Malpighiales, comprising six to nine genera and up to 700 species, and commonly known as the St. John's wort family. Members are found throughout the world apart from extremely cold or dry habitats. Hypericum and Triadenum occur in temperate regions but other genera are mostly tropical.
The Strelitziaceae comprise a family of monocotyledonous flowering plants, very similar in appearance and growth habit to members of the related families Heliconiaceae and Musaceae. The three genera with seven species of Strelitziaceae have been included in Musaceae in some classifications, but are generally recognized as a separate family in more recent treatments such as the APG II system (2003). The APG II system assigns the Strelitziaceae to the order Zingiberales in the commelinid clade.
Plumbaginaceae is a family of flowering plants, with a cosmopolitan distribution. The family is sometimes referred to as the leadwort family or the plumbago family.
Haemodoraceae is a family of perennial herbaceous flowering plants with 14 genera and 102 known species. It is sometimes known as the "bloodroot family". Primarily a Southern Hemisphere family, they are found in South Africa, Australia and New Guinea, and in the Americas. Perhaps the best known are the widely cultivated and unusual kangaroo paws from Australia, of the two closely related genera Anigozanthos and Macropidia.
The Crypteroniaceae are a family of flowering trees and shrubs. The family includes 13 species in three genera, native to Indomalaya.
The Calycanthaceae are a small family of flowering plants in the order Laurales. The family contains three genera and only 10 known species, restricted to warm temperate and tropical regions:
The Clethraceae are a small family of flowering plants in the order Ericales, composed of two genera, Clethra and Purdiaea, with approximately 75 species. They are native to warm temperate to tropical regions of Asia and the Americas, with one species also on Madeira.
The Eriocaulaceae are a family of monocotyledonous flowering plants in the order Poales, commonly known as the pipewort family. The family is large, with about 1207 known species described in seven genera. They are widely distributed, with the centers of diversity for the group occurring in tropical regions, particularly the Americas. Very few species extend to temperate regions, with only 16 species in the United States, mostly in the southern states from California to Florida, only two species in Canada, and only one species in Europe. They tend to be associated with wet soils, many growing in shallow water. This is also reported from the southern part of India and the regions of Western Ghats hot spots.
Caryocaraceae is a small family of flowering plants consisting of two genera with 26 species. The family is native to tropical regions of Central and South America, as well as the West Indies.
Dichapetalaceae is a family of flowering plants, consisting of 3 genera and about 170 species. Members of this family are trees, shrubs or lianas found in tropical and subtropical regions of the world.
Elatinaceae is a family of flowering plants with ca 35 species in two genera: Elatine and Bergia. The Elatine are mostly aquatic herbs, and the Bergia are subshrubs to shrubs. Elatine species are widely distributed throughout the world from temperate to tropical zones, with its greatest diversity found in temperate zones. Bergia is found in temperate to tropical Eurasia and Africa, with two tropical and one tropical to temperate species in the Americas. The center for biodiversity of Bergia is the Old World tropics, and this is also the center for biodiversity for the family. Neither genus is found in arctic ecosystems.
Humiriaceae is a family of evergreen flowering plants. It comprises 8 genera and 56 known species. The family is exclusively Neotropical, except one species found in tropical West Africa.
The Cyrillaceae are a small family of flowering plants in the order Ericales, native to warm temperate to tropical regions of the Americas. The family comprises two genera, Cliftonia and Cyrilla, each containing a single species, Cliftonia monophylla and Cyrilla racemiflora. However, additional species of Cyrilla are now often recognized and the genus is in need of taxonomic revision.
Staphyleaceae is a small family of flowering plants in the order Crossosomatales, native to Europe, temperate and tropical Asia and the Americas. The largest genus Staphylea, which gives the family its name, contains the "bladdernut" trees. The family includes three genera with more than 40 known species.
Philydraceae is a family of flowering plants composed of three genera and a total of six known species. Such a family has not been recognized by many taxonomists.
Schoepfiaceae is a family of flowering plants recognized in the APG III system of 2009. The family was previously only recognized by few taxonomists; the plants in question usually being assigned to family Olacaceae and Santalaceae.
Opiliaceae is a family of flowering plants comprising 11 genera and 33 known species. It consists of tropical woody plants. Several genera contain parasitic species. The biggest genus, in number of species and in stature of the individual plants, is Agonandra, the only American genus.
Nitrariaceae is a family of flowering plants in the order Sapindales. It comprises four genera, Malacocarpus, Nitraria, Peganum and Tetradiclis, totalling 19 species.
Huaceae is a family of plant in the rosids group, which has been classed in the orders Malpighiales, Malvales, and Violales or in its own order Huales. The APG II system placed it in the clade eurosids I, whereas the APG III system of 2009 and APG IV (2016) place it within the Oxalidales. The family is endemic to central Africa. It contains four species in the following two genera:
