Seed plants

Araceae taxonomy and systematics

The taxonomy of Araceae, the arum family, classifies about 150 genera and over 4,600 species into eight subfamilies, with duckweeds nested inside and generic limits actively redrawn.

Arachis

Arachis (peanut genus) is a South American legume genus in Fabaceae, tribe Dalbergieae, with about 69-84 species in nine sections; its type species Arachis hypogaea is the allotetraploid cultivated peanut derived from A. duranensis and A. ipaensis.

Arachis pintoi

Arachis pintoi (pinto peanut, forage peanut, maní forrajero), a stoloniferous perennial Fabaceae legume from central Brazil, used as tropical forage, cover crop, and living mulch; fixes 88–244 kg N/ha/yr; cultivar Amarillo; high invasion risk in Florida.

Aralia racemosa

Aralia racemosa, American spikenard (grande salsepareille), a thornless 60-180 cm herbaceous perennial of Araliaceae native to eastern North America, with aromatic roots once used in root beer and folk medicine.

Araliaceae

Araliaceae (ginseng or ivy family), Juss. 1789, order Apiales: 46 accepted genera, about 2,000 species of tropical and subtropical trees, shrubs, lianas, and herbs, including Panax, Hedera, Schefflera, and Polyscias.

Araucaria

Araucaria, monkey puzzle tree genus (Araucaria Juss.), a genus of 19 southern-hemisphere conifer species in Araucariaceae, from Jurassic fossils to the Endangered Araucaria araucana of Chile and Argentina.

Araucaria angustifolia

Araucaria angustifolia, Paraná pine or araucária, a critically endangered dioecious conifer of southern Brazil and Misiones, Argentina; source of edible pinhão seeds, once Brazil's dominant timber tree, with over 97% of its 200,000 km² forest lost.

Araucaria araucana

Araucaria araucana, the monkey puzzle tree or pewen, is an endangered Chilean-Argentine conifer of Araucariaceae, sacred to the Mapuche-Pewenche, a Chilean Natural Monument and CITES Appendix I species.

Araucaria bidwillii

Araucaria bidwillii, the bunya pine or bunya-bunya, is a large evergreen conifer native to subtropical eastern Australia, producing some of the largest and heaviest cones of any living conifer.

Araucaria cunninghamii

Araucaria cunninghamii (hoop pine, colonial pine, Moreton Bay pine) is a 50–70 m Araucariaceae conifer native to New Guinea and eastern Australia, section Eutacta, IUCN Least Concern, with four genetic groups and major plantation timber use.

Araucaria heterophylla

Araucaria heterophylla, the Norfolk Island pine (syn. Araucaria excelsa), is a Vulnerable Araucariaceae conifer endemic to Norfolk Island, grown worldwide as a coastal tree and houseplant, with 10-15 lb cones.

Araucariaceae

Araucariaceae, the southern conifer family with genera Araucaria, Agathis, and Wollemia, about 41 species, Triassic origin, sister to Podocarpaceae, now centered in New Caledonia, New Guinea, Australia, and South America.

Araucariaceae by region: floras and conservation status

A regional survey of Araucariaceae, the Southern Hemisphere conifer family of monkey puzzles, kauris, and the Wollemi pine, listing species counts and conservation status by region.

Árbol del Tule

Árbol del Tule (El Árbol del Tule, ahuehuete, sabino) is a giant Montezuma cypress in Santa María del Tule, Oaxaca, Mexico, the world's greatest-circumference tree: 36.2 m girth, 14.05 m diameter, over 2,000 years old by many estimates.

Arbutus

Arbutus (madrones, strawberry trees) is a genus of 12 accepted evergreen Ericaceae species with red exfoliating bark, urn-shaped flowers, and berry fruit, native from Macaronesia and the Mediterranean to western Canada and Central America.

Arbutus unedo

Arbutus unedo, the strawberry tree (madroño, medronheiro), is a Mediterranean Ericaceae evergreen shrub or small tree with white urn-shaped autumn flowers and warty red fruits that ripen a year after flowering; used for medronho brandy, honey, and jams.

Arceuthobium

Arceuthobium (dwarf mistletoes), genus of hemi-parasitic flowering plants on conifers; 39 accepted species, conserved against Razoumofskya; explosive seed dispersal up to 16 m; major North American forest pathogen.

Archaeopteris

Archaeopteris, an extinct Devonian progymnosperm tree (wood genus Callixylon), is the earliest known modern tree, about 385–360 million years old, reaching up to 40 m, dominating Late Devonian forests worldwide before seed plants radiated.

Arctium

Arctium (burdock) is a genus of about 10-11 biennial Asteraceae herbs native to temperate Eurasia, known for hooked burs that inspired Velcro, the edible and medicinal root of A. lappa, and introduced weedy status in North America.

Arctium lappa

Arctium lappa (greater burdock, gobō, niu bang 牛蒡) is a biennial Asteraceae herb native to temperate Eurasia, grown for its edible root in East Asia and studied medicinally for lignans arctiin and arctigenin.

Arctostaphylos uva-ursi

Arctostaphylos uva-ursi, bearberry or kinnikinnick, an Ericaceae subshrub whose arbutin-rich leaves are used traditionally for mild urinary tract infection symptoms in women; EU monograph limits use to one week.

Ardisia

Ardisia (marlberry) is a genus of about 740 accepted species in Primulaceae, pantropical trees and shrubs with gland-dotted leaves and one-seeded drupes, widely used in traditional medicine and including invasive species such as A. crenata.

Areca

Areca (betel nut palms) is a genus of about 45 accepted species of single-stemmed Asian palms in Arecaceae, native from South China and India to the Solomon Islands; Areca catechu yields the areca nut chewed by over 400 million people, and the houseplant "areca palm" is actually Dypsis lutescens.