Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and northern Asia, introduced elsewhere. The standard English name in its native area is creeping thistle; the plant is beneficial for pollinators. It was a top producer of nectar sugar in a 2016 study in Britain, with a second-place ranking due to a production per floral unit of. A number of other names are used in other areas or have been used in the past, including: Canada thistle, Canadian thistle, lettuce from hell thistle, California thistle, corn thistle, cursed thistle, field thistle, green thistle, hard thistle, perennial thistle, prickly thistle, small-flowered thistle, way thistle and stinger-needles; the first two names are in wide use in the United States, despite being a misleading designation and the last name a common term used in Newfoundland, Canada. As a subclassification of the "Eudicot" monophyletic group, Cirsium is a "true dicotyledon"; the number of pollen grain furrows or pores helps classify the flowering plants, with eudicots having three colpi.
Cirsium arvense is a C3 carbon fixation plant. The C3 plants originated during Mesozoic and Paleozoic eras, tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, ground water is plentiful. C3 plants lose 97% of the water taken up through their roots to transpiration. Creeping thistle is a herbaceous perennial plant growing up to 150 cm, forming extensive clonal colonies from thickened roots that send up numerous erect shoots during the growing season, it is a ruderal species. Its underground structure consists of four types, 1) long, horizontal roots, 2) long, vertical roots, 3) short, fine shoots, 4) vertical, underground stems. Though asserted in some literature, creeping thistle does not form rhizomes. Root buds form adventitiously on the thickened roots of creeping thistle, give rise to new shoots. Shoots can arise from the lateral buds on the underground portion of regular shoots if the shoots are cut off through mowing or when stem segments are buried. Stems are 30–150 cm, slender green, branched and glabrous without spiny wings.
Leaves are alternate on the stem with their base sessile and clasping or shortly decurrent. The leaves are spiny, up to 15–20 cm long and 2–3 cm broad; the inflorescence is 10–22 mm in diameter, pink-purple, with all the florets of similar form. The flowers are dioecious, but not invariably so, with some plants bearing hermaphrodite flowers; the seeds are 4 -- 5 mm long, with a feathery pappus. One to 5 flower heads occur per branch, with plants in favourable conditions producing up to 100 heads per shoot; each head contains an average of 100 florets. Average seed production per plant has been estimated at 1530. More seeds are produced when male and female plants are closer together, as flowers are insect-pollinated. Variation in leaf characters is the basis for determining creeping thistle varieties. According to Flora of Northwest Europe the two varieties are: Cirsium arvense var. arvense. Most of Europe. Leaves thinly hairy beneath. Cirsium arvense var. incanum Ledeb. Southern Europe. Leaves thickly hairy beneath.
The Biology of Canadian Weeds: Cirsium arvense list four varieties: Cirsium arvense var. vestitum. Leaves gray-tomentose below. Cirsium arvense var. integrifolium. Leaves all entire or the upper leaves entire and the lower stem leaves shallowly and pinnatifid or undulating. Cirsium arvense var. arvense. Leaves shallowly to pinnatifid asymmetrical. Cirsium arvense var. horridum. Leaves thick, surface wavy, marginal spines long and stout; the seeds are an important food for the goldfinch and the linnet, to a lesser extent for other finches. Creeping thistle foliage is used as a food by over 20 species of Lepidoptera, including the painted lady butterfly and the engrailed moth, several species of aphids; the flowers are visited by a wide variety of insects. The species is considered a weed where it is native, for example being designated an "injurious weed" in the United Kingdom under the Weeds Act 1959, it is a serious invasive species in many additional regions where it has been introduced accidentally as a contaminant in cereal crop seeds.
It is cited as a noxious weed in several countries. Many countries regulate this plant, or its parts as a contaminant of other imported products such as grains for consumption or seeds for propagation. In Canada, C. arvense is classified as a primary noxious weed seed in the Weed Seeds Order 2005 which applies to Canada's Seeds Regulations. Control methods include cutting at flower stem extension before the flower buds open to prevent seed spread. Repeated cutting at the same growth stage over several years may "wear down" the plant. Growing forages such as alfalfa can help control the species as a weed by cutting the alfalfa to add nutrients to the soil, the weeds get cut, have a harder time re-establishing themselves, which reduces the shoot density. Orellia ruficauda feeds on Canada thistle and has been reported to be the most effective biological control agent for that plant, its larvae parasitize the seed heads, feeding upon fertile seed heads. The weevil Larinus planus feeds on t
Pine nuts called piñón or pinoli, are the edible seeds of pines. About 20 species of pine produce seeds large enough to be worth harvesting. In Europe and places with a Mediterranean climate, two species in particular are harvested. Four other species, Siberian pine, Siberian dwarf pine, Chinese white pine and lacebark pine, are used to a lesser extent. Russia is the largest producer of Pinus sibirica nuts in the world followed by Mongolia which produces over 10,000 tonnes of forest grown nuts annually, the majority of harvest is exported to China. Afghanistan is an important source of pine nuts, behind Korea. Pine nuts produced in Europe come from the stone pine, cultivated for its nuts for over 5,000 years, harvested from wild trees for far longer; the Swiss pine is used to a small extent. In North America, the main species are three of the pinyon pines: Colorado pinyon, single-leaf pinyon, Mexican pinyon; the other eight pinyon species are used to a small extent, as are gray pine, Coulter pine, Torrey pine, sugar pine and Parry pinyon.
Here, the nuts themselves are known by the Spanish name for the pinyon pine: piñón. In the United States, pine nuts are harvested by Native American and Hispano communities in the Western United States and Southwestern United States, by the Uto-Aztecan Shoshone, Navajo, Hopi and Hispanos of New Mexico. Certain treaties negotiated by tribes and laws in Nevada guarantee Native Americans' right to harvest pine nuts, the state of New Mexico protects the use of the word piñon for use with pine nuts from certain species of indigenous New Mexican pines. For those seeking to grow edible landscapes, these are the more used species. Old World Pinus armandii – Chinese white pine Pinus bungeana – lacebark pine Pinus cembra – Swiss pine Pinus gerardiana – Chilgoza pine Pinus koraiensis – Korean pine Pinus pinea – Mediterranean stone pine Pinus pumila – Siberian dwarf pine Pinus sibirica – Siberian pine New World Pinus cembroides – Mexican pinyon Pinus culminicola – Potosi pinyon Pinus edulis – Two-needle piñon or Colorado pinyon Pinus johannis – Johann's pinyon Pinus monophylla – Single-leaf pinyon Pinus orizabensis – Orizaba pinyon Pinus quadrifolia – Parry pinyon Pinus remota – Texas pinyon or papershell pinyo The pine nut species will take a time that depends on the exact species to complete its maturity.
For some American species development begins in early spring with pollination. A tiny cone, about the size of a small marble, will form from mid-spring to the end of summer; the cone will commence growth until it reaches maturity near the end of summer. The mature piñon pine cone is ready to harvest ten days. A cone is harvested by placing it in a burlap bag and exposing it to a heat source such as the sun to begin the drying process, it takes about 20 days until the cone opens. Once it is open and dry, the seed can be extracted in various ways; the most common and practical extraction method used is the repeated striking of the burlap bag containing the cone against a rough surface to cause the cone to shatter, leaving just the job of separating by hand the seed from the residue within the bag. Another option for harvesting is to wait until the cone opens on the tree and harvest the cone from the piñon pine, followed by the extracting process mentioned above. Fallen seed can be gathered beneath the trees.
In the United States, millions of hectares of productive pinyon pine woods have been destroyed due to conversion of lands, in China, destructive harvesting techniques and the removal of trees for timber have led to losses in production capacity. The elevation of the pinyon pine is an important determinant of the quantity of pine cone production, therefore, will determine the amount of pine nuts the tree will yield. American Pinyon pine cone production is most found at an elevation between 6,000 feet and 8,500 feet, ideally at 7,000 feet; this is due to higher temperatures at elevations lower than 6,000 feet during the spring, which dry up humidity and moisture content that provide for the tree throughout the spring and summer, causing little nourishment for pine cone maturity. Although there are several other environmental factors that determine the conditions of the eco-system, without sufficient water the trees tend to abort cones. High humidity encourages cone development. There are certain topographical areas found in lower elevations, such as shaded canyons, where the humidity remains constant throughout the spring and summer, allowing pine cones to mature and produce seed.
At elevations above 8,500 feet, the temperature drops, dras
Umbellularia californica is a large hardwood tree native to coastal forests of California, as well as to coastal forests extending into Oregon. It is endemic to the California Floristic Province, it is the sole species in the genus Umbellularia. The tree was known as Oreodaphne californica. In Oregon, this tree is known as Oregon myrtle, while in California it is called California bay laurel, which may be shortened to California bay or California laurel, it has been called pepperwood, cinnamon bush, peppernut tree, headache tree, mountain laurel, balm of heaven. The tree's pungent leaves have a similar flavor to bay leaves, though stronger, it may be mistaken for bay laurel; the dry wood has a color range from blonde to brown. It is sought after by luthiers and woodworkers; the tree is a host of the pathogen. This tree inhabits redwood forests, California mixed woods, yellow pine forest, oak woodlands. Bays occur in oak woodlands only close to the coast, or in extreme northern California where moisture is sufficient.
During the Miocene, oak-laurel forests were found in Southern California. Typical tree species included oaks ancestral to present-day California oaks, an assemblage of trees from the laurel family, including Nectandra, Ocotea and Umbellularia. Only one native species from the laurel family, Umbellularia californica, remains in California today. In the north, it reaches its distributional limit through southwest Oregon to Newport, Lincoln County, Oregon, on the coast, extending from there south through California to San Diego County, it is found in the western foothills of the Sierra Nevada mountains. It occurs at altitudes from sea level up to 1600 m. An isolated, more northern occurrence of the species can be found in Tacoma, around Snake Lake near the Tacoma Nature Center. There are two recorded instances of trees growing in coastal British Columbia, it is an evergreen tree growing to 30 m tall with a trunk up to 80 cm thick. The largest recorded tree is in Mendocino County and measured 108 feet in height and 119 feet in spread.
The fragrant leaves are smooth-edged and lance-shaped, 3–10 cm long and 1.5–3 cm broad, similar to the related bay laurel, though narrower, without the crinkled margin of that species. The flowers are yellow or yellowish-green, produced in small umbels. Unlike other "bay laurels" of the genus Laurus, Umbellularia has perfect flowers; the fruit known as "California bay nut", is a round and green berry 2–2.5 cm long and 2 cm broad spotted with yellow, maturing purple. Under the thin, leathery skin, it consists of an oily, fleshy covering over a single hard, thin-shelled pit, resembles a miniature avocado. Umbellularia is in fact related to the avocado's genus Persea, within the Lauraceae family; the fruit ripens around October–November in the native range. Umbellularia has long been valued for its many uses by Native Americans throughout the tree's range, including the Cahuilla, Pomo, Yuki and Salinan people; the Concow tribe call the plant sō-ē’-bä. The leaf has been used as a cure for headache and earache—though the volatile oils in the leaves may cause headaches.
Poultices of Umbellularia leaves were used to treat rheumatism and neuralgias. A tea was made from the leaves to treat stomach aches, sore throats, to clear up mucus in the lungs; the leaves were steeped in hot water to make an infusion, used to wash sores. The Pomo and Yuki tribes of Mendocino County treated headaches by placing a single leaf in the nostril or bathing the head with a laurel leaf infusion; the chemical responsible for the headache-inducing effects of Umbellularia is known as umbellulone. Both the flesh and the inner kernel of the fruit have been used as food by Native Americans; the fatty outer flesh of the fruit, or mesocarp, is palatable raw for only a brief time. Native Americans dried the fruits in the sun and ate only the lower third of the dried mesocarp, less pungent; the hard inner seed underneath the fleshy mesocarp, like the pit of an avocado, cleaves in two when its thin shell is cracked. The pit itself was traditionally roasted to a dark chocolate-brown color, removing much of the pungency and leaving a spicy flavor.
Roasted, shelled "bay nuts" were eaten whole, or ground into powder and prepared as a drink which resembles unsweetened chocolate. The flavor, depending on roast level, has been described variously as "roast coffee," "dark chocolate" or "burnt popcorn"; the powder might be used in cooking or pressed into cakes and dried for winter storage. It has been speculated; the leaf can be used in cooking, but is spicier and "headier" than the Mediterranean bay leaf, should be used in smaller quantity. Umbellularia leaf imparts a somewhat stronger camphor/cinnamon flavor compared to the Mediterranean bay; some modern-day foragers and wild food enthusiasts have revived Native American practices regarding the edible roasted fruit, the bay nut. Umbellularia californica is used in woodworking, it is considered a tonewood, used to construct the sides of acoustic guitars. The wood is hard and fine, is made into bowls and other small items and sold as "myrtlewood", it is grown as an ornamental tre
Rubus parviflorus called thimbleberry, is a species of Rubus native to North America. Rubus parviflorus is native to western North America from Alaska south as far as California, New Mexico and San Luis Potosí, its range extends east discontinuously to the Great Lakes Region. It grows from sea level in the north, up to elevations of 3,000 m in the south. Rubus parviflorus grows along roadsides, railroad tracks, in forest clearings appearing as an early part of the ecological succession in clear cut and forest fire areas. Thimbleberry is found in forest understories with typical flora associates including coastal woodfern, Trillium ovatum and Smilacina racemosa. Rubus parviflorus is a dense shrub up to 2.5 meters tall with canes no more than 1.5 centimeters in diameter growing in large clumps which spread through the plant's underground rhizome. Unlike many other members of the genus, it has no prickles; the leaves are palmate, up to 20 centimeters across, with five lobes. The flowers are 2 to 6 centimeters in diameter, with five white petals and numerous pale yellow stamens.
The flower of this species is among the largest of any Rubus species, making its Latin species name parviflorus a misnomer. The plant produces edible composite fruit a centimeter in diameter, which ripen to a bright red in mid to late summer. Like other raspberries it is not a true berry, but instead an aggregate fruit of numerous drupelets around a central core; the drupelets may be removed separately from the core when picked, leaving a hollow fruit which bears a resemblance to a thimble giving the plant its name. Thimbleberry fruits are smaller and softer than raspberries, have many small seeds; because the fruit is so soft, it does not pack or ship well, so thimbleberries are cultivated commercially. However, the wild thimbleberries can be eaten raw or dried and can be made into a jam, sold as a local delicacy in some parts of their range, notably in the Keweenaw Peninsula of Upper Michigan. Thimbleberry jam is made by combining equal volumes of berries and sugar and boiling the mixture for two minutes before packing it into jars.
Without sugar the cooked berries with their distinguished sweet sour taste are good for a while in the refrigerator and can be added to all kinds of desserts and vinaigrettes. Rubus parviflorus is cultivated by specialty plant nurseries as an ornamental plant, used in traditional, native plant, wildlife gardens, in natural landscaping design, in habitat restoration projects; the fruit has fragrance. Thimbleberry plants can be propagated most by planting dormant rhizome segments, as well as from seeds or stem cuttings; the flowers support pollinators, including of special value to Native bees and bumblebees. The fruit is attractive to birds, it is a nectar source for the yellow-banded sphinx moth. Cultivars of the plant are selected for ornamental qualities, such as for their fragrant flowers and/or attractive fall foliage color. A double-flowered form of the thimbleberry was discovered near Squamish, BC, by Iva Angerman of West Vancouver, BC; this clone does not appear to be in commerce, but is grown in the Botanic Garden of the University of British Columbia, in the Native Plant Garden of the Royal British Columbia Museum, Victoria.
Another double-flowered thimbleberry was found about 1975 by Bob Hornback on Starrett Hill, Monte Rio and given the cultivar name'Dr. Stasek', after an art instructor at Sonoma State University. Many parts of the Rubus parviflorus plant were used for a great variety of medicinal purposes by Native Americans. Thimbleberries are high in Vitamin C as well as A and can be used to treat scurvy. A poultice of the dried, powdered leaves can be used to treat wounds and burns, as well as the fresh ones to treat acne. A tea made from its leaves or roots can be used as a treatment for nausea, vomiting diarrhea and dysentery. Thimbleberry leaves can be used as a natural toilet paper; the Concow tribe calls the plant wä-sā’. Media related to Rubus parviflorus at Wikimedia Commons Calflora database: Rubus parviflorus
Clover or trefoil are common names for plants of the genus Trifolium, consisting of about 300 species of flowering plants in the legume or pea family Fabaceae. The genus has a cosmopolitan distribution with highest diversity in the temperate Northern Hemisphere, but many species occur in South America and Africa, including at high altitudes on mountains in the tropics, they are small biennial, or short-lived perennial herbaceous plants. Clover can be evergreen; the leaves are trifoliate, cinquefoil, or septfoil), with stipules adnate to the leaf-stalk, heads or dense spikes of small red, white, or yellow flowers. Other related genera called clovers include Melilotus and Medicago. Several species of clover are extensively cultivated as fodder plants; the most cultivated clovers are white clover, Trifolium repens, red clover, Trifolium pratense. Clover, either sown alone or in mixture with ryegrass, has for a long time formed a staple crop for silaging, for several reasons: it grows shooting up again after repeated mowings.
In many areas on acidic soil, clover is short-lived because of a combination of insect pests and nutrient balance. When crop rotations are managed so that clover does not recur at intervals shorter than eight years, it grows with much of its pristine vigor. Clovers are most efficiently pollinated by bumblebees, which have declined as a result of agricultural intensification. Honeybees can pollinate clover, beekeepers are in heavy demand from farmers with clover pastures. Farmers reap the benefits of increased reseeding that occurs with increased bee activity, which means that future clover yields remain abundant. Beekeepers benefit from the clover bloom. Trifolium repens, white or Dutch clover, is a perennial abundant in good pastures; the flowers are pinkish, becoming brown and deflexed as the corolla fades. Trifolium hybridum, alsike or Swedish clover, is a perennial, introduced early in the 19th century and has now become naturalized in Britain; the flowers are white or rosy, resemble those of Trifolium repens.
Trifolium medium, meadow or zigzag clover, a perennial with straggling flexuous stems and rose-purple flowers, has potential for interbreeding with T. pratense to produce perennial crop plants. Other species are: hare's - foot trefoil. Shamrock, the traditional Irish symbol, which according to legend was coined by Saint Patrick for the Holy Trinity, is associated with clover, although alternatively sometimes with the various species within the genus Oxalis, which are trifoliate. Clovers have four leaflets, instead of the usual three; these four-leaf clovers, like other rarities, are considered lucky. Clovers can have five, six, or more leaflets, but these are rarer still; the record for most leaflets is 56, set on 10 May 2009. This beat the "21-leaf clover", a record set in June 2008 by the same discoverer, who had held the prior Guinness World Record of 18. A common idiom is "to be in clover", meaning to live a carefree life of ease, comfort, or prosperity; the cloverleaf interchange is named for the resemblance to the leaflets of a clover when viewed from the air.
The first extensive classification of Trifolium was done by Zohary and Heller in 1984. They divided the genus into eight sections: Lotoidea, Mistyllus, Chronosemium, Trifolium and Involucrarium, with Lotoidea placed most basally. Within this classification system, Trifolium repens falls within section Lotoidea, the largest and least heterogeneous section. Lotoidea contains species from America and Eurasia, considered a clade because of their inflorescence shape, floral structure, legume that protrudes from the calyx. However, these traits are not unique to the section, are shared with many other species in other sections. Zohary and Heller argued that the presence of these traits in other sections proved the basal position of Lotoidea, because they were ancestral. Aside from considering this section basal, they did no propose relationships between other sections. Since molecular data has both questioned and confirmed the proposed phylogeny from Zohary and Heller. A genus-wide molecular study has since proposed a new classification system, made up of two subgenera and Trifolium.
This recent reclassification further divides subgenus Trifolium into eight sections. The molecular data supports the monophyletic nature of three sections proposed by Zohary and Heller, but not of Lotoidea. Other molecular studies, although smaller, support the need to reorganize Lotoidea; the genus Trifolium has 245 recognized
Yosemite Valley is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of Central California. The valley is about 7.5 miles long and 3000–3500 feet deep, surrounded by high granite summits such as Half Dome and El Capitan, densely forested with pines. The valley is drained by the Merced River, a multitude of streams and waterfalls flow into it, including Tenaya, Illilouette and Bridalveil Creeks. Yosemite Falls is the highest waterfall in North America, is a big attraction in the spring when the water flow is at its peak; the valley is renowned for its natural environment, is regarded as the centerpiece of Yosemite National Park, attracting visitors from around the world. The Valley is the main attraction in the park for the majority of visitors, a bustling hub of activity during tourist season in the summer months. Most visitors pass through the Tunnel View entrance. Visitor facilities are located in the center of the valley. There are both hiking trail loops that stay within the valley and trailheads that lead to higher elevations, all of which afford glimpses of the park's many scenic wonders.
Yosemite Valley is located on the western slope of the Sierra Nevada mountains, 150 miles due east of San Francisco. It stretches for 7.5 miles in a east–west direction, with an average width of about 1 mile. Yosemite Valley represents only one percent of the park area, but this is where most visitors arrive and stay. More than half a dozen creeks tumble from hanging valleys at the top of granite cliffs that can rise 3000–3500 feet above the valley floor, which itself is 4000 ft above sea level; these streams combine into the Merced River, which flows out from the western end of the valley, down the rest of its canyon to the San Joaquin Valley. The flat floor of Yosemite Valley holds both forest and large open meadows, which have views of the surrounding crests and waterfalls. Below is a description of these features, looking first at the walls above, moving west to east as a visitor does when entering the valley visiting the waterfalls and other water features, returning east to west with the flow of water.
The first view of Yosemite Valley many visitors see is the Tunnel View. So many paintings were made from a viewpoint nearby that the National Park Service named that viewpoint Artist Point; the view from the lower end of the Valley contains the great granite monolith El Capitan on the left, Cathedral Rocks on the right with Bridalveil Fall. Just past this spot the Valley widens with the Cathedral Spires the pointed obelisk of Sentinel Rock to the south. Across the Valley on the northern side are the Three Brothers, rising one above the other like gables built on the same angle – the highest crest is Eagle Peak, with the two below known as the Middle and Lower Brothers. To this point the Valley has been curving to the left. Now a grand curve back to the right begins, with Yosemite Falls on the north, followed by the Royal Arches, topped by North Dome. Opposite, to the south, is Glacier Point, 3,200 feet above the Valley floor. At this point the Valley splits in two, one section slanting northeast, with the other curving from south to southeast.
Between them, at the eastern end of the valley, is Half Dome, among the most prominent natural features in the Sierra Nevada. Above and to the northeast of Half Dome is Clouds Rest. Snow melting in the Sierra forms lakes. In the surrounding region, these creeks flow to the edge of the Valley to form cataracts and waterfalls. A fan of creeks and forks of the Merced River take drainage from the Sierra crest and combine at Merced Lake; the Merced flows down to the end of its canyon, where it begins what is called the Giant Staircase. The first drop is Nevada Fall. Below is one of the most picturesque waterfalls in the Valley; the Merced descends rapids to meet Illilouette Creek, which drops from the valley rim to form Illilouette Fall. They combine at the base of the gorges that contain each stream, flow around the Happy Isles to meet Tenaya Creek at the eastern end of Yosemite Valley proper. Tenaya Creek flows southwest from Tenaya Lake and down Tenaya Canyon flowing between Half Dome and North Dome before joining the Merced River.
The following falls tumble from the Valley rim to join it at various points: Yosemite Falls 2,425 feet Upper Yosemite Fall 1,430 feet, the middle cascades 670 feet, Lower Yosemite Fall 320 feet. Snow Creek Falls 2,140 feet Sentinel Falls 1,920 feet Ribbon Fall 1,612 feet Royal Arch Cascade 1,250 feet Lehamite Falls 1,180 feet Staircase Falls 1,020 feet Bridalveil Fall 620 feet. Nevada Fall 594 feet Silver Strand Falls 574 feet Vernal Fall 318 feet The features in Yosemite Valley are made of granitic rock emplaced as plutons miles deep during the late Cretaceous. Over time the Sierra Nevada was uplifted; the oldest of these granitic rocks, at 114 million years, occur along the Merced River Gorge west of the valley. The El Capitan pluton intruded the valley, forming most of the granitic rock that makes up much of the central part of the valley, including Cathedral Rocks, Three Brothers, El Capitan; the youngest Yosemite Valley pluton is the 87-million-year-old Half Dome granodiorite, which makes up most of the rock at
Common sorrel or garden sorrel simply called sorrel, is a perennial herb in the family Polygonaceae. Other names for sorrel include spinach narrow-leaved dock, it is cultivated as a garden herb or salad vegetable. Sorrel is a slender herbaceous perennial plant about 60 centimetres high, with roots that run deep into the ground, as well as juicy stems and edible, arrow-shaped leaves; the leaves, when consumed raw, have a sour taste. The lower leaves are 7 to 15 centimetres in length with long petioles and a membranous ocrea formed of fused, sheathing stipules; the upper ones are sessile, become crimson. It has whorled spikes of reddish-green flowers; the species is dioecious, with pistils on different plants. The leaves are eaten by the larvae of several species of Lepidoptera including the blood-vein moth. Rumex acetosa occurs in grassland habitats throughout Europe from the northern Mediterranean coast to the north of Scandinavia and in parts of Central Asia, it occurs as an introduced species in parts of North America.
Several subspecies have been named. Not all are cultivated: Rumex acetosa ssp. acetosa Rumex acetosa ssp. ambiguus Rumex acetosa ssp. arifolius Rumex acetosa ssp. hibernicus Rumex acetosa ssp. hirtulus Rumex acetosa ssp. vinealis Common sorrel has been cultivated for centuries. The leaves may be added to salads; the plant's sharp taste is due to oxalic acid. In northern Nigeria, sorrel is used in stews with spinach. In some Hausa communities, it is steamed and made into salad using kuli-kuli, pepper and tomatoes. In India, the leaves are used in curries made with yellow lentils and peanuts. In Afghanistan, the leaves are coated in a wet batter and deep fried served as an appetizer or if in season during Ramadan, for breaking the fast. Throughout eastern Europe, wild or garden sorrel is used to make sour soups, stewed with vegetables or herbs, meats or eggs. In rural Greece, it is used with spinach and chard in spanakopita. In Albania, the leaves are simmered and served cold marinated in olive oil, or as an ingredient for filling byrek pies.
In Armenia, the leaves are collected in spring, woven into braids, dried for use during winter. The most common preparation is aveluk soup, where the leaves are rehydrated and rinsed to reduce bitterness stewed with onions, walnuts and bulgur wheat or lentils, sometimes sour plums. Rumex acetosella, sheep's sorrel Rumex scutatus, French sorrel Oxalis, wood sorrel Oxalis enneaphylla, scurvy-grass sorrel Sorrel soup