Rice — Domesticated rice Poaceae (“true grass”) family, Oryza sativa and Oryza glaberrima. These plants are native to tropical and subtropical southern Asia and southeastern Africa. Rice provides more than one fifth of the calories consumed worldwide by humans. (The term “wild rice” can refer to the wild species of Oryza, but conventionally refers to species of the related genus …

Rhubarb — Rheum is a genus of perennial plants that grow from thick short rhizomes. The genus is in the family Polygonaceae, and includes the vegetable rhubarb (Rheum rhabarbarum or Rheum x hybridum). The plants have large leaves that are somewhat triangular shaped with long fleshy petioles. The flowers are small, greenish-white to rose-red, and borne in large compound leafy …

Rhododendron — Rhododendron is a genus of flowering plants in the family Ericaceae. It is a large genus with over 1000 species and most have showy flower displays. It includes the plants known to gardeners as azaleas. The Rhododendron is a genus characterized by shrubs and small to (rarely) large trees, the smallest species growing to 10-20 cm tall, and …

Redwood, Giant — Sequoiadendron giganteum (Giant Sequoia, Sierra Redwood, Wellingtonia or Big Tree) is the sole species in the genus Sequoiadendron, and one of three species of coniferous trees known as redwoods, classified in the family Cupressaceae in the subfamily Sequoioideae, together with Sequoia sempervirens (Coast Redwood) and Metasequoia glyptostroboides (Dawn Redwood). Giant Sequoia is the world’s largest tree in …

Redwood, Coast — Sequoia is a genus in the cypress family Cupressaceae (formerly treated in Taxodiaceae), containing the single living species Sequoia sempervirens. Common names include Coast Redwood and California Redwood (it is one of three species of trees known as redwoods). It is an evergreen, long-lived, monoecious tree living for up to 2,200 years, and is the tallest tree …

Redbud — “Cercis”, the Redbuds’, is a genus of about 6-10 species in the subfamily Caesalpinioideae of the pea family Fabaceae, native to warm-temperate regions. They are small deciduous trees or large shrubs, characterised by simple, rounded to heart-shaped leaves and pinkish-red flowers borne in the early spring on bare leafless shoots. udas-tree (Cercis siliquastrum) is a small tree to …

Raspberry — The raspberry (plural, raspberries) is the edible fruit of a number of species of the genus Rubus; the name also applies to these plants themselves. The name originally referred to the European species Rubus idaeus, with red fruit, and is still used for that species as its standard English name in its native area. Several other species, mostly …

Ragweed — Ragweeds (Ambrosia), also called bitterweeds and bloodweeds, are a genus of flowering plants from the sunflower family (Asteraceae). The scientific name of this genus is sometimes claimed to be derived from the Ancient Greek term for the perfumed nourishment of the gods, ambrosia which would be ironic since the genus is best known for one fact: its pollen …

Radish — The radish (Raphanus sativus) is an edible root vegetable of the Brassicaceae family that was domesticated in Europe in pre-Roman times. They are grown and consumed throughout the world, and in addition to their use as a food, radishes have uses as an alternative treatment for a variety of medical conditions. Radishes have numerous varieties, varying in size, …

Quince — The Quince, or Cydonia oblonga, is the sole member of the genus Cydonia and native to warm-temperate southwest Asia in the Caucasus region. It is a small deciduous tree, growing 5-8 m tall and 4-6 m wide, related to apples and pears, and like them has a pome fruit, which is bright golden yellow when mature, pear-shaped, 7-12 …