4,295 articles
Stamen
Stamen: the male reproductive organ of a flower, made of an anther that produces pollen and a filament stalk; collectively the androecium. Differs from the pistil (female) and from gymnosperm pollen organs, which lack thecae.
Stanhopea
Stanhopea (J.Frost ex Hook.) is a Neotropical epiphytic orchid genus in subtribe Stanhopeinae, native from Mexico to southern tropical America and Trinidad, with roughly 55–78 accepted species, pendent few-flowered inflorescences, and euglossine bee pollination via fragrant osmophores.
Stapelia
Stapelia (carrion flowers) is a genus of about 30 southern African stem succulents in Apocynaceae, with foetid, nectarless, fly-pollinated flowers from 1 cm to 40 cm across.
Star gooseberry
Star gooseberry (Sauropus androgynus, katuk, sweet leaf; accepted name Breynia androgyna) is a Southeast Asian leafy shrub eaten as a nutritious vegetable but linked to bronchiolitis obliterans when raw juice is consumed excessively.
Starch
Starch (amylum): plant storage polysaccharide of amylose and amylopectin; over 50 million tons produced yearly from maize, rice, potatoes; used in food, paper, textiles, glucose, and bioplastics.
Stelechocarpus burahol
Stelechocarpus burahol, kepel or burahol, an Annonaceae tree native to Borneo and southern Malesia, grown mainly in central Java for an aromatic fruit once reserved for Javanese royalty as a natural perfume.
Stelis
Stelis (leach orchid) is a huge Neotropical orchid genus in Pleurothallidinae, founded by Olof Swartz in 1799–1800, with over 1,300 accepted species of minute-flowered epiphytes from Mexico to tropical America, centered in the Andes.
Stellaria
Stellaria (starworts, chickweeds) is a genus of ~110–150 Caryophyllaceae herbs, type S. graminea, Miocene origin in northern Eurasia; best-known species is common chickweed (Stellaria media), an edible weed used in traditional medicine.
Stellaria media
Stellaria media, common chickweed, is a Caryophyllaceae winter annual weed native to temperate Eurasia and North Africa, producing up to 15,000 seeds per plant, edible but invasive, with ALS herbicide resistance confirmed in Ireland.
Sterculia
Sterculia L. is a pantropical genus of about 170 to 300 tree and shrub species in Malvaceae (Sterculioideae), source of karaya gum from Sterculia urens and widely used in traditional medicine.
Sterculia urens
Sterculia urens (karaya gum tree, Indian tragacanth, ghost tree) is a large deciduous Malvaceae tree native from the Indian Subcontinent to Indo-China, source of gum karaya (E 416), used in food, pharma, and textiles, endangered in parts of India.
Stevia
Stevia: Stevia rebaudiana, the Paraguayan sweet-leaf shrub, its steviol glycoside sweeteners (200-300x sucrose), production, JECFA/EU/FDA regulation, ADI 4 mg/kg bw, and health evidence.
Stevia rebaudiana
Stevia rebaudiana (caa-ehe) is a Paraguayan and Brazilian Asteraceae herb whose leaves contain steviol glycosides such as stevioside and rebaudioside A, sweeteners 40–300 times sweeter than sucrose with an ADI of 4 mg/kg bw/day.
Sticherus
Sticherus (umbrella ferns) is a pantropical genus of about 89 species of forked Gleicheniaceae ferns with scaly buds, single-rowed sori, and monolete spores; genomic phylogeny showed paraphyly, leading to Sticheropsis segregation in 2024.
Sticherus tener
Sticherus tener, known as the Silky Fan-fern or Tasman Fan-fern, is a creeping fan-fern in the Gleicheniaceae family native to Victoria, Tasmania, and New Zealand's southern South Island.
Stipa
Stipa (feather grasses, needlegrasses) is a Poaceae genus of perennial tussock grasses with twisted, hygroscopic awns; about 141 accepted Old World species, centered in Middle Asian steppes, type species S. pennata.
Stoma
Stoma (plural stomata): microscopic pores on plant surfaces, each formed by two guard cells, regulating CO2 uptake and transpiration; about 90% of plant water loss passes through them, and they originated over 400 million years ago.
Stone pine
Stone pine (Pinus pinea), Mediterranean umbrella pine of Section Pinea, source of pignoli pine nuts; symbol of Rome, ~6,000 t/yr world shelled production, threatened by Leptoglossus occidentalis and Diplodia blight.
Strangler fig
绞杀榕 (strangler figs) are hemiepiphytic Ficus trees, such as Ficus tinctoria and F. benjamina, that germinate on host trees, root into the soil, and may kill their hosts; urbanization boosts their colonization but blocks later establishment.
Stratiotes aloides
Stratiotes aloides, water soldier or water aloe, is the sole living species of the monotypic genus Stratiotes (Hydrocharitaceae), a dioecious Eurasian aquatic perennial with spiny rosette leaves that floats in summer and sinks in winter, invasive in Ontario.
Straw
Straw: dry stalks of cereal crops (wheat, barley, rice) left after grain harvest, seed-free unlike hay. Used for livestock feed and bedding, thatching, mulch, biofuel, and straw-bale construction; composition and burning rules covered.
Strawberries and Cream Tree
The Strawberries and Cream Tree is a rare graft-chimaera cherry tree in Backwell, North Somerset, England, flowering pink and white on one trunk from two cherry species.
Strawberry
Strawberry (Fragaria × ananassa), the cultivated garden strawberry, an octoploid hybrid of F. virginiana and F. chiloensis arising in 1750s France; grown as June-bearing, everbearing, and day-neutral cultivars, with day-neutrals driving California's yield doubling since the 1970s.
Strelitzia
Strelitzia, bird-of-paradise or crane flower genus, five southern African species in Strelitziaceae; named for Queen Charlotte, bird-pollinated via feet, S. reginae most cultivated.
Strelitzia reginae
Strelitzia reginae, known as the bird-of-paradise flower or crane flower, is a South African perennial herb grown worldwide for its orange and blue flowers that resemble a bird's head.
Streptocarpus
Streptocarpus (Cape primrose), genus of ~160 African and Madagascan herbs in Gesneriaceae, type species S. rexii (1828); since 2015 includes African violets (Saintpaulia), with twisted capsules and major horticultural importance.
Streptocarpus ionanthus
Streptocarpus ionanthus, the African violet (formerly Saintpaulia ionantha), is a lithophytic Gesneriaceae herb native to Kenya and Tanzania, divided into nine subspecies, widely cultivated as an ornamental houseplant.
Striga hermonthica
Striga hermonthica (purple witchweed), Orobanchaceae hemiparasitic annual weed native to Africa, parasitizes maize, sorghum, and millets via strigolactone-triggered germination and haustoria, causing 30–80% cereal yield losses across sub-Saharan Africa.
Strobilanthes
Strobilanthes (Blume, 1826) is a large Asian genus of Acanthaceae, about 200 to 473 species, known for periodical 6- to 12-year mass flowering, indigo-yielding S. cusia, and a broad synonymized taxonomy.
Stromatolite
Stromatolites: layered organosedimentary structures built by microbial mats trapping sediment and precipitating minerals; Earth's dominant early-life fossil record, from disputed 3.7 Ga Isua examples to living Shark Bay and Bahamas reefs, and a key Mars analog.