The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vegetative and floral features makes it difficult to define common features that unify the order.
The Santalales are an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions. It derives its name from its type genus Santalum (sandalwood). Mistletoe is the common name for a number of parasitic plants within the order.
Ceratophyllum is a cosmopolitan genus of flowering plants including four accepted living species in 2016, commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions. It is the only extant genus in the family Ceratophyllaceae, itself the only extant family in the order Ceratophyllales. They are usually called coontails or hornworts, although hornwort is also used for unrelated plants of the division Anthocerotophyta.
Geraniaceae is a family of flowering plants placed in the order Geraniales. The family name is derived from the genus Geranium. The family includes both the genus Geranium and the garden plants called geraniums, which modern botany classifies as genus Pelargonium, along with other related genera.
The Piperaceae, also known as the pepper family, are a large family of flowering plants. The group contains roughly 3,600 currently accepted species in 5 genera. The vast majority of species can be found within the two main genera: Piper and Peperomia.
Nartheciaceae is a family of flowering plants. The APG III system places it in the order Dioscoreales, in the clade monocots. As circumscribed by APG IV (2016) it includes 35 species of herbaceous plants in the following five genera:
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 Potamogetonaceae, commonly referred to as the pondweed family, is an aquatic family of monocotyledonous flowering plants. The roughly 110 known species are divided over six genera. The largest genus in the family by far is Potamogeton, which contains about 100 species.
Zosteraceae is a family of marine perennial flowering plants found in temperate and subtropical coastal waters, with the highest diversity located around Korea and Japan. Most seagrasses complete their entire life cycle under water, having filamentous pollen especially adapted to dispersion in an aquatic environment and ribbon-like leaves that lack stomata. Seagrasses are herbaceous and have prominent creeping rhizomes. A distinctive characteristic of the family is the presence of characteristic retinacules, which are present in all species except members of Zostera subgenus Zostera.
Adoxaceae, commonly known as moschatel family, is a small family of flowering plants in the order Dipsacales, now consisting of five genera and about 150–200 species. They are characterised by opposite toothed leaves, small five- or, more rarely, four-petalled flowers in cymose inflorescences, and the fruit being a drupe. They are thus similar to many Cornaceae.
Nyctaginaceae, the four o'clock family, is a family of around 33 genera and 290 species of flowering plants, widely distributed in tropical and subtropical regions, with a few representatives in temperate regions. The family has a distinctive fruit type called an accessory fruit or anthocarp, and many genera have extremely large pollen grains.
Schisandraceae is a family of flowering plants with 3 known genera and a total of 92 known species. Such a family has been recognized by most taxonomists, at least for the past several decades. Before that, the plants concerned were assigned to family Magnoliaceae and Illiciaceae.
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.
Peridiscaceae is a family of flowering plants in the order Saxifragales. Four genera comprise this family: Medusandra, Soyauxia, Peridiscus, and Whittonia., with a total of 12 known species. It has a disjunct distribution, with Peridiscus occurring in Venezuela and northern Brazil, Whittonia in Guyana, Medusandra in Cameroon, and Soyauxia in tropical West Africa. Whittonia is possibly extinct, being known from only one specimen collected below Kaieteur Falls in Guyana. In 2006, archeologists attempted to rediscover it, however, it proved unsuccessful.
Scheuchzeria palustris, is a flowering plant in the family Scheuchzeriaceae, in which there is only one species and Scheuchzeria is the only genus. In the APG II system it is placed in the order Alismatales of the monocots.
Tofieldiaceae is a family of flowering plants in the monocot order Alismatales. The family is divided into four genera, which together comprise 28 known species. They are small, herbaceous plants, mostly of arctic and subarctic regions, but a few extend further south, and one genus is endemic to northern South America and Florida. Tofieldia pusilla is sometimes grown as an ornamental.
Goodeniaceae is a family of flowering plants in the order Asterales. It contains about 404 species in twelve genera. The family is distributed mostly in Australia, except for the genus Scaevola, which is pantropical. Its species are found across most of Australia, being especially common in arid and semi-arid climates.
Butomus is the only known genus in the plant family Butomaceae, native to Europe and Asia. It is considered invasive in some parts of the United States.
Tetracarpaea is the only genus in the flowering plant family Tetracarpaeaceae. Some taxonomists place it in the family Haloragaceae sensu lato, expanding that family from its traditional circumscription to include Penthorum and Tetracarpaea, and sometimes Aphanopetalum as well.
Hydrostachys is a genus of about 22 species of flowering plants native to Madagascar and southern and central Africa. It is the only genus in the family Hydrostachyaceae. All species of Hydrostachys are aquatic, growing on rocks in fast-moving water. They have tuberous roots, usually pinnately compound leaves, and highly reduced flowers on dense spikes.
