3,306 articles
Rhizome
Rhizome: a horizontally growing modified plant stem at or just below the soil surface, bearing buds and roots at nodes; examples include iris, bamboo, and ginger; distinct from bulbs, corms, tubers, and stolons.
Rhizophora
Rhizophora is a genus of six accepted mangrove tree species in Rhizophoraceae, including the red mangrove R. mangle, defined by prop roots, over 90% root salt exclusion, and buoyant viviparous propagules that disperse by floating.
Rhizophora apiculata
Rhizophora apiculata (kongkang) is an Indo-West Pacific mangrove tree of Rhizophoraceae, dominant on estuarine mud from South Asia to Queensland, parent of two hybrids, used for charcoal and wood, IUCN Least Concern.
Rhizophora mangle
Rhizophora mangle, the red mangrove, is a viviparous stilt-rooted evergreen tree of tropical intertidal coasts of America and West Africa, tolerating 0-90 ppt salinity, IUCN Least Concern, invasive in Hawaii and Queensland.
Rhizophora mucronata
Rhizophora mucronata, Asiatic or loop-root mangrove (Rhizophoraceae), is a viviparous Indo-Pacific mangrove tree to 25 m with stilt roots and pointed leaves; bark yields tannin, parts serve traditional medicine, and it is IUCN Least Concern.
Rhizophoraceae
Rhizophoraceae, the red mangrove family, is a mainly Old World tropical family of 15–16 genera and about 145 species in Malpighiales, including about half of the world's true mangrove species.
Rhodiola rosea
Rhodiola rosea (rosenroot, arctic root, golden root), Crassulaceae succulent perennial of the subarctic Northern Hemisphere; root used traditionally as an adaptogen for stress and fatigue; EU traditional-use monograph; clinical evidence inconclusive; wild stocks overharvested.
Rhododendron
Rhododendron, including azaleas, is a large Ericaceae genus of 850+ woody species native from the temperate Northern Hemisphere to tropical Asian mountains and NE Australia, with leathery leaves, showy bell-shaped flowers, and winged seeds.
Rhododendron ferrugineum
Rhododendron ferrugineum, the alpenrose or alpine rose, is a dwarf evergreen Ericaceae shrub of the European Alps and Pyrenees, the type species of Rhododendron, flowering rosy scarlet at 1,700–2,500 m on acid, non-limestone soils.
Rhododendron ponticum
Rhododendron ponticum, an evergreen Ericaceae shrub native to the Black Sea region and Iberia, introduced to Britain in 1763, now one of the most destructive invasive plants of the British Isles, forming dense thickets and hosting Phytophthora ramorum.
Rhus typhina
Rhus typhina (staghorn sumac, Rhus hirta) is a suckering North American shrub or small tree of Anacardiaceae, 15-25 ft tall with velvety branches and red hairy fruit; harmless, unlike poison sumac (Toxicodendron vernix), and a 17th-century European introduction.
Rhynchospora
Rhynchospora (beaksedge) is a cosmopolitan genus of about 392 sedge species in Cyperaceae, tribe Rhynchosporeae, defined by a persistent beak-like style base on the nutlet, richest in tropical America, with holocentric chromosomes.
Ribes
Ribes (currants and gooseberries) is a genus of about 195 accepted shrub species in Grossulariaceae, native from subarctic to tropical American mountains, cultivated for black, red, and white currants and gooseberries, and alternate host of white pine blister rust.
Rice
Rice (Oryza sativa), annual grass staple for over half the world's people; japonica domesticated in the Yangtze valley ~11,000 BP, indica via japonica introgression; 552.5 Mt milled output forecast 2026/27.
Rice bran extract
Rice bran extract is a water-extracted ingredient from rice bran used as a moisture retention agent and sodium phosphate alternative in processed meats, GRAS under FDA GRN 884 (Florida Food Products, closed August 2020) at up to 1.25% by weight.
Rice bran fiber
Rice bran fiber, a concentrated dietary fiber mechanically isolated from defatted rice bran; GRAS in the US under FDA GRN 373 (CJ America, 2011, no-questions letter) for food use excluding meat and poultry.
Rice bran oil
Rice bran oil (RBO, rice oil) is an edible oil from the bran of Oryza sativa, rich in gamma-oryzanol and vitamin E, requiring bran stabilization against lipase, refined physically, and shown in meta-analyses to lower LDL and total cholesterol.
Rice cake
A rice cake is either a chewy Asian cake such as Korean tteok, Japanese mochi, or Chinese nian gao, or the Western puffed snack marketed as a low-calorie food.
Rice field art
Rice field art (tanbo art, 田んぼアート): images grown in rice paddies by planting colored-leaf rice varieties, originating 1993 in Inakadate Village, Aomori, Japan; perspective-corrected designs viewed from platforms, Gyoda holds the 2.8-hectare world record.
Rice flour
Rice flour, also known as rice powder, is flour ground from milled rice. Prized as gluten-free, hypoallergenic, and bland, it is the most common flour in gluten-free bread.
Rice noodles (米粉)
Rice noodles (米粉, mifen, mixian) are gluten-free noodles made from indica rice flour via gelatinization, molding, and retrogradation. Originating in China, documented from the 6th-century Qi Min Yao Shu, they are a staple of southern China and Southeast Asia.
Rice vermicelli
Rice vermicelli (mifen, bún, bee hoon, sen mee): thin round noodles extruded from gelatinized rice flour, a staple of Chinese and Southeast Asian cuisine; GI 35-62, 341-377 kcal/100 g dry, distinct from Italian wheat vermicelli and glass noodles.
Richardia brasiliensis
Richardia brasiliensis (tropical Mexican clover, Brazil pusley), a prostrate Rubiaceae herb native from Ecuador to northern Argentina, naturalized as a weed of turf, soybean, and corn across Florida, Australia, Asia, and Africa.
Ricinus
Ricinus, castor bean or castor oil plant (Ricinus communis L.), sole species of its Euphorbiaceae genus, native to NE tropical Africa, domesticated ~3200 years ago; seeds yield ricinoleic-acid-rich castor oil and the toxin ricin.
Ripening
Ripening, also known as fruit ripening, is the final phase of fruit maturation, a hormonally regulated process of pigment accumulation, softening, and aroma development; climacteric fruits like bananas ripen after harvest, while strawberries do not.
Robinia pseudoacacia
Robinia pseudoacacia, black locust or false acacia, is a fast-growing, nitrogen-fixing North American tree introduced to Europe in the early 17th century, widely planted for durable wood and honey yet ranked among Europe's 100 most invasive alien species.
Rolled oats
Rolled oats are whole oat groats steamed and pressed into flat flakes 0.4–1 mm thick, sold as old-fashioned, quick, or instant oats. Developed by Ferdinand Schumacher in the 1870s, they cook in about 10 minutes and have a GI of 40–69.
Romulea
Romulea (romulea) is a genus of about 90-120 cormous Iridaceae herbs of Africa and the Mediterranean, centered in southern Africa, with two subgenera, high polymorphism, hybridization, and polyploidy.
Root
Root (botany): the plant organ that anchors the plant and absorbs water and minerals. Also called taproot or fibrous root systems; evolved independently in at least two vascular plant lineages in the Early Devonian, c. 410-395 million years ago.
Root vegetable
Root vegetable: culinary category of edible underground storage organs, including taproots (carrot, beet), tuberous roots (sweet potato), stem tubers (potato), corms, rhizomes, and bulbs; starchy staple crops central to food security.