Plants named in 1804

Forsythia , is a genus of flowering plants in the olive family Oleaceae. There are about 11 species, mostly native to Eastern Asia, but one native to Southeastern Europe. Forsythia – also one of the plant's common names – is named after the botanist William Forsyth.

Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with about 731 known species in 41 genera. Well known genera include Commelina (dayflowers) and Tradescantia (spiderworts). The family is diverse in both the Old World tropics and the New World tropics, with some genera present in both. The variation in morphology, especially that of the flower and inflorescence, is considered to be exceptionally high amongst the

Colchicaceae is a family of flowering plants that includes 15 genera with a total of about 285 known species according to Christenhusz and Byng in 2016. The family is characterized by the presence of colchicine.

Selaginella, also known as spikemosses or lesser clubmosses, is a genus of lycophyte. It is usually treated as the only genus in the family Selaginellaceae, with over 750 known species. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. They are sometimes included in an informal paraphyletic group called the "fern allies". The species S. moellendorffii is an important model organism. Its genome has been sequenced by the United States Department of Energy's Joint Genome Institute. The name Selaginella was

Populus × canescens, the grey poplar, is a hybrid between Populus alba (white poplar) and P. tremula (common aspen). It is intermediate between its parents, with a thin grey downy coating on the leaves, which are much less deeply lobed than the leaves of P. alba. It is a very vigorous tree with marked hybrid vigour, reaching 40 metres (130 feet) tall and with a trunk diameter over 1.5 m (5 ft) – much larger than either of its parents. Most trees in cultivation are male, but female trees occur naturally and some of these are also propagated.

Trifolium campestre, commonly known as hop trefoil, field clover and low hop clover, is a species of flowering plant native to Europe and western Asia.

Rhizophora mucronata (loop-root mangrove, red mangrove or Asiatic mangrove) is a species of mangrove found on coasts and river banks in East Africa and the Indo-Pacific region.

Fraxinus angustifolia, the narrow-leaved ash, is a species of Fraxinus native to Central Europe and Southern Europe, Northwest Africa, and Southwest Asia.

Paeonia × suffruticosa is a group of tree peony cultivars that are the result of hybridization with peony species exclusively belonging to the subsection Vaginatae. The common name used in China is mǔdān (Chinese: 牡丹) or Moutan peony. Cultivars of this group have been cultivated in Chinese floriculture for millennia, initially only as a source of traditional Chinese medicine, particularly for the skin of their roots (牡丹皮; mǔdān pí). Already early on, the plant was also cultivated for its ornamental value, and it is highly revered in Chinese culture. Paeonia × suffruticosa is a perennial

Loasaceae is a family of 15–20 genera and about 200–260 species of flowering plants in the order Cornales, native to the Americas and Africa. Members of the family include annual, biennial and perennial herbaceous plants, and a few shrubs and small trees. Members of the subfamily Loasoideae are known to exhibit rapid thigmonastic stamen movement when pollinators are present.

Angraecum, also known as comet orchid, is a genus of the family Orchidaceae native to tropical and South Africa, as well as Sri Lanka. It contains 223 species.

Scilla siberica, the Siberian squill or wood squill, is a species of flowering plant in the family Asparagaceae, native to southwestern Russia, the Caucasus, and Turkey. Despite its name, it is not native to Siberia. Many parts of the plant such as the flowers, fruits, leaves, roots, sap, seeds, and stem are poisonous to eat for some animals.

Sternbergia is a genus of Eurasian and North African plants in the Amaryllis family, subfamily Amaryllidoideae. The genus comprises eight recognised species that show a broad distribution throughout the Mediterranean Basin as well as central and southwestern Asia.

Pandanus utilis, commonly known as common screwpine or pimento thatch, is a species of monocot in the genus Pandanus, native to the Mascarene Islands of Mauritius, Rodrigues, and Réunion, and naturalised in Madagascar (where it has often been thought native), the Seychelles, and elsewhere.

Bomarea is one of the two major genera in the plant family Alstroemeriaceae. Most occur in the Andes, but some occur well into Central America, Mexico and the West Indies. Some species are grown as ornamental plants.

Celeriac (Apium graveolens Rapaceum Group, synonyms Apium graveolens Celeriac Group and Apium graveolens var. rapaceum), also called celery root, knob celery, and turnip-rooted celery (although it is not a close relative of the turnip), is a group of cultivars of Apium graveolens cultivated for their edible bulb-like hypocotyl, and shoots. Celeriac is widely cultivated in the Mediterranean Basin and in Northern Europe. It is also but less commonly cultivated in North Africa, Siberia, Southwest Asia, and North America.

Stachytarpheta jamaicensis is a species of plant in the family Verbenaceae, native throughout the Caribbean, including Florida. It has many common names including blue porterweed, blue snake weed, bastard vervain, Brazilian tea, Jamaica vervain, light-blue snakeweed, and, in St. Croix, worryvine.source? It usually is found along country roadsides, and it also grows well as a ruderal plant on disturbed terrain. A similar plant, Stachytarpheta cayennensis, which is an invasive species in Florida, is sometimes mistaken for S. jamaicensis. It is unclear whether S. indica is a separate species.

Blandfordia, commonly known as Christmas bells, is a genus of four species of flowering plants native to eastern Australia. Christmas bells are tufted, perennial herbs with narrow, linear leaves and up to twenty large, drooping, cylindrical or bell-shaped flowers.

Salvia elegans is a perennial shrub native to Mexico. It has a number of variants, including pineapple sage and tangerine sage.

Galeopsis ladanum var. angustifolia, the red hemp-nettle, is a European annual plant growing to 30 cm tall. It flowers between June and October on waste ground, railway tracks, and other stony places. It is classified as critically endangered, having declined dramatically in the last 60 years due to increased fertiliser and herbicide. Modern farming techniques such as autumn cultivation have also affected the plant because they are killed before they have set seed.

Ceroxylon is a genus of flowering plants in the family Arecaceae, native to the Andes in Venezuela, Colombia, Ecuador, Peru, and Bolivia, known as Andean wax palms. The species are almost exclusively montane and include the tallest palm (and thus tallest monocotyledon), C. quindiuense, which reaches 61 m (200 ft) in height, and species growing at the highest altitude of the palm family (Arecaceae), at more than 3,000 m (10,000 ft) in elevation. The genus name is derived from Ancient Greek κηρός (kērós ("wax") and ξύλον (xúlon, "wood").

Stachytarpheta is a plant genus in the verbena family (Verbenaceae). The flowers are rich in nectar and popular with many butterflies, such as the South Asian crimson rose, Malabar banded swallowtail, and grass yellow. Hummingbirds, especially small species like Lophornis coquettes, Chlorostilbon emeralds, and Discosura thorntails, are especially attracted for nectar. Several species in this genus are known as porterweeds. In Australia the genus is known as snakeweed.

Ornithopus sativus, the serradella or common birdsfoot, is a species of flowering plant in the family Fabaceae. It is native to Southwestern Europe and Northwest Africa in Portugal, western Spain, northern Morocco and Algeria, and southwestern France and has been introduced as a legume forage to many locations around the world, including most of central and eastern Europe, Turkey, the Caucasus, the Azores, South Africa, Kenya, Java, most of Australia, the North Island of New Zealand, southern Chile, and California. It is known for producing a high‑quality forage in highly acidic,

Nemesia is a genus of annuals, perennials and sub-shrubs which are native to sandy coasts or disturbed ground in South Africa. Numerous hybrids have been selected, and the annual cultivars are popular with gardeners as bedding plants. In temperate regions they are usually treated as half-hardy, grown from seed in heat, and planted out after all danger of frost has passed. The flowers are two-lipped, with the upper lip consisting of four lobes and the lower lip two lobes. The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-

Sparaxis is a genus of flowering plants called the harlequin flowers. It belongs to the iris family Iridaceae with about 13 species endemic to Cape Province, South Africa. All are perennials that grow during the wet winter season, flower in spring and survive underground as dormant corms over summer. Their conspicuous flowers have six tepals, which in most species are equal in size and shape. Sparaxis bulbifera has flowers from cream to yellow or purple. Sparaxis grandiflora is a similar but larger plant. In cultivation in the UK it has gained the Royal Horticultural Society's Award of Garden

Pyrola media, the intermediate wintergreen, is a flowering plant in the genus Pyrola, native to northern and eastern Europe and Western Asia. It is a herbaceous evergreen perennial plant with a basal rosette of leaves and a single erect flowering stem 15–30 cm tall. The leaves are round, up to 4.5 cm diameter. The flowers are white or pale pink, 7–11 mm diameter, with a straight style extending beyond the petals. The species is rare and declining in the British Isles.

Sternbergia colchiciflora is a bulbous flowering plant in the family Amaryllidaceae, subfamily Amaryllidoideae, which is sometimes used as an ornamental plant, commonly known as babaluschka. The species is native to southern Europe from Spain to Russia (in the Stavropol and Krasnodar Krai regions, as well as in the Chechen Republic), as well as from Morocco, Algeria, Turkey, Syria, Lebanon, the Palestine region, Iran and the Caucasus. It has yellow flowers which appear in autumn.

Salvia azurea, the blue sage or azure sage, is a herbaceous perennial in the genus Salvia that is native to Central and Eastern North America.

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.

Aloe striata, with the common name coral aloe, is a small, stemless South African Aloe species.