PS10 Solar Power Plant (Planta Solar 10) — solar power tower near Seville PS10 solar power plant PS10 is a commercial solar power tower near Seville, Spain. Commissioned in 2007, it uses 624 heliostats to concentrate sunlight onto a central receiver to produce steam and about…
Pseudanthium (flower head): structure, function and examples Pseudanthium A pseudanthium (false flower) is a compact inflorescence that mimics a single flower. Typical of Asteraceae, it groups many small florets into a single display that facilitates pol…
Punica — the pomegranate genus Punica Punica is a small genus of fruit-bearing deciduous shrubs and small trees in the family Lythraceae, best known for the pomegranate and its cultural, culinary, and horticultural rol…
Pyrola (wintergreens): overview, taxonomy and ecology Pyrola Pyrola, commonly called wintergreens or shinleaves, is a small group of evergreen woodland herbs in the heath family (Ericaceae). This entry covers identification, classification,…
Quillajaceae (soapbark family) Quillajaceae A small family of South American flowering trees in the genus Quillaja (two species). Bark rich in saponins used traditionally as soap and today as natural surfactants and vaccine…
Rafflesia: the giant parasitic flower of Southeast Asia Rafflesia Rafflesia is a genus of parasitic flowering plants native to Southeast Asia, notable for producing the largest single flowers and for lacking stems, leaves or chlorophyll.
Rafflesiaceae — parasitic flowering plants of Southeast Asia Rafflesiaceae Rafflesiaceae is a small family of obligate parasitic flowering plants known for giant, short-lived flowers and an internalized vegetative body. Found mainly in Southeast Asia, the…
Rambutan (Nephelium lappaceum): tropical fruit tree and its fruit Rambutan Rambutan is a tropical tree native to Southeast Asia, known for its hairy red rind and sweet translucent flesh. This article covers appearance, origin, cultivation, uses, varieties…
Ramie (Boehmeria nivea): the fiber plant from the nettle family Ramie Ramie (Boehmeria nivea) is a perennial Asian plant grown for its strong, lustrous bast fiber. It requires degumming, has a long cultivation history, and is used in textiles and ind…
Ranunculaceae — the buttercup family Ranunculaceae Ranunculaceae, the buttercup or crowfoot family, is a diverse group of mostly temperate flowering plants valued in gardens and studied for their distinctive flowers, fruits, and of…
Ranunculales — an order of flowering plants Ranunculales Ranunculales is a basal eudicot order that includes buttercups and related families; notable for diverse flower forms, many free floral parts, alkaloids, ornamental and medicinal s…
Rapeseed (Brassica napus) — oilseed crop overview Rapeseed Rapeseed (Brassica napus) is an oilseed crop in the mustard family grown for vegetable oil, animal feed and industrial uses; low‑erucic, low‑glucosinolate types are marketed as can…
Rapid plant motions: mechanisms, examples and biological limits Rapid plant movement Overview of rapid plant motions: mechanisms, examples and biological limits. Explains hydraulic, elastic and buckling-driven movements in species from Venus flytrap to mulberry and…
Raspberry (aggregate fruit): description, cultivation, uses Raspberry Comprehensive overview of the raspberry: botanical nature, key characteristics, cultivation and varieties, culinary and ecological uses, and distinctions from similar fruits.
Red huckleberry (Vaccinium parvifolium) Red huckleberry A small evergreen shrub native to western North American forests, known for flattened leaves and bright edible red berries used by wildlife and people.
Red pine (Pinus resinosa) Red pine Red pine (Pinus resinosa) is a North American conifer known for its reddish bark, paired needles, and importance for timber, reforestation, and wildlife habitat across northeastern…
Redcurrant (Ribes rubrum): description, uses and cultivation Redcurrant Redcurrant (Ribes rubrum) is a small, tart berry from a deciduous shrub native to western Europe. Used fresh or cooked in jams, sauces and beverages; grown in gardens and orchards.
Redwood (Sequoioideae): species, ecology, size, and conservation Redwood Redwoods are a group of large coniferous trees in the subfamily Sequoioideae. This article covers their taxonomy, distinguishing features, ecology, notable individuals, uses, and c…
Reed: plant, musical, and mechanical meanings Reed Comprehensive overview of reeds: wetland plants, vibrating strips in wind instruments, and mechanical/electrical components. Covers biology, use in music, materials, cultural histo…
Reed (plant): ecology, uses, and cultural history Reed (plant) Reeds are tall, grass-like wetland plants found in reed beds. This article explains their form, ecology, common species, human uses (thatching, crafts, habitat management), and how…
Resin: plant secretion, properties, history, and human uses Resin Resin is a sticky plant secretion, rich in organic compounds. It protects plants, attracts natural enemies of herbivores, fossilizes to amber, and has many industrial, artistic, an…
Rhododendron: overview, characteristics, history and uses Rhododendron Rhododendron is a diverse genus of woody flowering plants in the heath family, prized for large showy blooms and widely grown as ornamentals; includes azaleas and many Asian native…
Rhododendron niveum: a high‑altitude rhododendron of the eastern Himalaya Rhododendron niveum Rhododendron niveum is an evergreen shrub or small tree native to northeastern India, Bhutan and southern Tibet, found at 2600–3500 m and noted for its leathery leaves and magenta‑…
Rhododendron ponticum — pontic or common rhododendron Rhododendron ponticum An evergreen shrub native to southern Europe and western Asia. Noted for glossy leaves and clusters of purple flowers, it is grown ornamentally but can form invasive thickets outsi…
Rhopalostylis sapida (nīkau) — New Zealand's native palm Rhopalostylis sapida Rhopalostylis sapida, commonly called nīkau, is the only palm native to New Zealand. A shade-tolerant coastal understorey species, it has ecological importance and a rich history o…
Rhubarb Perennial plant of the genus Rheum cultivated for its tart edible stalks and for medicinal roots; notable for poisonous leaves and use in desserts, preserves and traditional medici…
Rhynia — Early Devonian fossil genus of simple vascular plants Rhynia Rhynia is an Early Devonian fossil plant genus represented by R. gwynne-vaughanii. Its well‑preserved remains reveal simple leafless axes, terminal sporangia and early vascular tis…
Ribes: the genus of currants and gooseberries Ribes Ribes is a genus of about 150 species of shrubs and small trees, including currants and gooseberries, native to temperate regions of the Northern Hemisphere and valued for fruit, o…
Richea: Tasmanian and Australian genus of the heath family Richea Richea is a small genus of evergreen shrubs and trees in the Ericaceae family, native to Tasmania and parts of southeastern Australia, known for long straplike leaves and clusters…
Romaine lettuce (cos): characteristics, uses, and cultivation Romaine lettuce Romaine (cos) lettuce is an elongated-leaf variety of Lactuca sativa valued for its crisp midribs, mild flavor, and culinary uses such as Caesar salad; cultivated worldwide with Me…
Rooibos (Aspalathus linearis): South African red bush tea Rooibos Rooibos is a caffeine-free herbal infusion from Aspalathus linearis, a leguminous shrub native to South Africa. Known for its reddish brew and green unoxidized form, it is used as…
Plant root Root Overview of plant roots: structure, types, functions, ecological roles, and distinctions from stems; includes examples, adaptations and human uses.
Root hair: structure, function, development, and importance Root hair Root hairs are tubular single-cell extensions of root epidermis that increase surface area for water and nutrient uptake; they are short-lived and continually renewed near the grow…
Root vegetable: definition, types, uses and cultivation Root vegetable Edible underground plant parts—roots, tubers, bulbs and corms—collected as vegetables. Overview of types, botanical distinctions, common examples, nutrition, cooking, and cultivati…
Rosaceae: the rose family — overview, traits, fruits, and uses Rosaceae Rosaceae, the rose family, is a diverse group of woody and herbaceous plants that includes roses, apples, pears, cherries, strawberries and many ornamentals and crops important wor…
Rosales (order of flowering plants) Rosales Rosales is an order of flowering plants that contains nine families including roses, many fruit trees, figs, nettles, hops and cannabis; important for food, ornamentals and other u…
Rose (Rosa) — Biology, Cultivation, Uses, and Cultural Significance Rose Overview of the rose (genus Rosa): botanical features, diversity of species and cultivars, history of cultivation, common uses, and practical care and distinctions.
Rose garden (Rosarium): design, history, cultivation, and significance Rose garden Comprehensive article about rose gardens (rosaria): their design, history, types of roses displayed, cultivation and cultural importance, with notable examples and distinctions.
Rosemary (Rosmarinus officinalis) — aromatic evergreen herb Rosemary Rosemary is a woody, evergreen herb from the Mediterranean with needle-like leaves. Widely used in cooking, ornamentals, and traditional medicine; notable for fragrance, drought to…
Rosewood (Dalbergia): characteristics, species, uses and conservation Rosewood Rosewood is timber from Dalbergia trees prized for color, fragrance and tonal qualities. This article covers major species, properties, common uses, trade issues and conservation c…
Rosidae — a historical subclass of flowering plants Rosidae Rosidae is a botanical subclass name historically used to group rosid-like flowering plants; its circumscription varies by system but always includes the rose family (Rosaceae).
Rosids Rosids are a major clade of eudicot flowering plants, containing about 70,000 species in roughly 17 orders and 140 families; they arose in the Cretaceous and include many crops and…
Rosmarinus (rosemary): overview, characteristics, and uses Rosmarinus Rosmarinus, once recognized as the rosemary genus, comprises aromatic evergreen shrubs native to the Mediterranean. Valued for culinary, medicinal and ornamental uses; taxonomy now…
Rosoideae: the rose subfamily of the Rosaceae family Rosoideae Rosoideae is a subfamily within Rosaceae including roses, strawberries, raspberries and related herbaceous and woody plants, valued for ornamentals and edible fruits.
Rowan (Sorbus) — cool‑climate fruiting trees of the rose family Rowan Small deciduous trees or shrubs in genus Sorbus (Rosaceae), rowans have pinnate leaves, white spring flowers and clusters of colorful pomes eaten by wildlife and used in traditiona…
Rubiaceae: the madder, bedstraw and coffee family Rubiaceae Rubiaceae is a large, mainly tropical family of flowering plants (about 600 genera, over 10,000 species) that includes coffee, quinine producers, dyes, ornamentals and many herbace…
Rubus: the brambles and berries of the rose family Rubus Rubus is a diverse genus of flowering shrubs and canes in the rose family, including raspberries, blackberries, dewberries and cloudberries; valued for fruit, wildlife habitat, and…
Rutaceae: the rue and citrus family Rutaceae Rutaceae is a family of flowering plants that includes citrus, rue and many aromatic shrubs and trees. Members are notable for oil glands, diverse fruit forms and important culinar…
