Cyclanthaceae

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.

Petrosaviaceae is a family of flowering plants belonging to a monotypic order, Petrosaviales. Petrosaviales are monocots, and are grouped within the lilioid monocots. Petrosaviales is a very small order composed of one family, two genera and four species accepted in 2016. Some species are photosynthetic (Japonolirion) and others are rare, leafless, chlorophyllous, mycoheterotrophic plants (Petrosavia). The family is found in low-light montane rainforests in Japan, China, Southeast Asia and Borneo. They are characterised by having bracteate racemes, pedicellate flowers, six persistent tepals, septal nectaries, three almost-distinct carpels, simultaneous microsporogenesis, monosulcate pollen, and follicular fruit.

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:

Lardizabalaceae is a family of flowering plants.

Juncaginaceae is a family of flowering plants, recognized by most taxonomists for the past few decades. It is also known as the arrowgrass family. It includes 3 genera with a total of 34 known species.

Hypoxidaceae is a family of flowering plants, placed in the order Asparagales of the monocots.

Trimeniaceae is a family of flowering plants recognized by most taxonomists, at least for the past several decades. It is a small family of one genus, Trimenia, with eight known species of woody plants, bearing essential oils. The family is subtropical to tropical and found in Southeast Asia, eastern Australia and on several Pacific Islands.

Circaeasteraceae is a family of two species of herbaceous plants native to China and the Himalayas.

Berberidopsidaceae is a family of flowering plants. Such a family has only recently been recognized by more than a few taxonomists: the plants involved have often been treated as belonging to family Flacourtiaceae.

The Thurniaceae are a family of flowering plants composed of two genera with four species. The botanical name has been recognized by most taxonomists.

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.

Boryaceae is a family of highly drought-tolerant flowering plants native to Australia, placed in the order Asparagales of the monocots. The family includes two genera, with twelve species in total in Australia.

Ixiolirion is a genus of flowering plants native to central and southwest Asia, first described as a genus in 1821. Recent classifications place the group in the monogeneric family Ixioliriaceae in the order Asparagales of the monocots. In earlier systems of classification, it was usually placed in the family Amaryllidaceae.

Tecophilaeaceae is a family of flowering plants, placed in the order Asparagales of the monocots. It consists of nine genera with a total of 27 species.

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.

Calophyllaceae is a family of flowering plants in the order Malpighiales and is recognized by the APG III system of classification. Most of the 14 genera and 475 species included in this family were previously recognized in the tribe Calophylleae of the family Clusiaceae. The Angiosperm Phylogeny Group determined that splitting this clade of genera off into their own family was necessary.

Centroplacaceae is a family of flowering plants in the order Malpighiales and is recognized by the APG III system of classification. The family comprises two genera: Bhesa, which was formerly recognized in the Celastraceae, and Centroplacus, which was formerly recognized in the Euphorbiaceae, together comprising six species. The Angiosperm Phylogeny Group determined that based on previous phylogenetic analysis, these two genera formed an isolated clade and recognition of the family was "reasonable."