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Least Lettuce
''Lactuca saligna'' is a species of wild lettuce known by the common name willowleaf lettuce, and least lettuce. It is native to Eurasia but it grows in many other places as an introduced species, including much of North America. It can be found rarely in south-east England on dry banks near the sea and estuaries. Description ''Lactuca saligna'' is an annual herb growing from a taproot to heights of , and occasionally taller. It is much slenderer than great lettuce '' Lactuca virosa'' and prickly lettuce ''Lactuca serriola.'' The spindly, mainly erect stem has bristles on its lower portion. The leaves are very long and narrow, up to long but rarely than wide, usually with no lobes and no teeth. The top part of the stem is occupied by a narrow inflorescence. The branches may be pressed against the main stem, or they may branch outward. The flower head is up to about wide when open, with rectangular pale yellow ray florets with toothed tips. There are no disc florets. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacob Sturm
Jacob Sturm (21 March 1771 – 28 November 1848) was a leading engraver of entomological and botanical scientific publications in Germany at the end of the 18th and beginning of the 19th century. He was born and lived in Nuremberg and was the only son of engraver Johann Georg Sturm (1742-1793), who trained him in drawing and copperplate engraving. Sturm became a celebrated insect collector and founded the Nuremberg Society for Natural History. His entomological and botanical plates are very accurately drawn and show minute details and enjoyed a great popularity among naturalists. As most of his works were published in a small format, they could be purchased by a larger public and they were very popular. During this period, Nuremberg was the centre of natural history book production in Germany. "The book ''Deutschlands Flora'',lit.: ''Germany's flora in pictures from nature with descriptions. Nuremberg, printed at the expense of the author'' 1798–1862. 163 parts (in 136 vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactuca Serriola
''Lactuca serriola'', also called prickly lettuce, milk thistle (not to be confused with ''Silybum marianum'', also called milk thistle), compass plant, and scarole, is an annual or biennial plant in the tribe Cichorieae within the family Asteraceae. It has a slightly fetid odor and is commonly considered a weed of orchards, roadsides and field crops. It is the closest wild relative of cultivated lettuce (''Lactuca sativa'' L.). ''Lactuca serriola'' is known as the compass plant because in the sun the upper leaves twist round to hold their margins upright. ''Lactuca serriola'' is native to Europe, Asia, and north Africa, and has become naturalized elsewhere. Description ''Lactuca serriola'' has a spineless reddish stem, containing a milky latex, growing up to . The leaves get progressively smaller as they reach its top. They are oblong or lanceolate, often pinnately lobed and (especially for the lower leaves), waxy grey green. Fine spines are present along the veins and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants Described In 1753
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pappus (flower Structure)
In Asteraceae, the pappus is the modified calyx, the part of an individual floret, that surrounds the base of the corolla tube in flower. It functions as a wind-dispersal mechanism for the seeds. The term is sometimes used for similar structures in other plant families e.g. in certain genera of the Apocynaceae, although the pappus in Apocynaceae is not derived from the calyx of the flower. In Asteraceae, the pappus may be composed of bristles (sometimes feathery), awns, scales, or may be absent, and in some species, is too small to see without magnification. In genera such as ''Taraxacum'' or ''Eupatorium'', feathery bristles of the pappus function as a "parachute" which enables the seed to be carried by the wind. The name derives from the Ancient Greek word ''pappos'', Latin ''pappus'', meaning "old man", so used for a plant (assumed to be an ''Erigeron'' species) having bristles and also for the woolly, hairy seed of certain plants. The pappus of the dandelion plays a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteraceae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. Most species of Asteraceae are annual, biennial, or perennial herbaceous plants, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. The primary common characteristic is the existence of sometimes hundreds of tiny individual florets which are held together by protective involucres in flower heads, or more technicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not open at maturity). Achenes contain a single seed that nearly fills the pericarp, but does not adhere to it. In many species, what is called the "seed" is an achene, a fruit containing the seed. The seed-like appearance is owed to the hardening of the fruit wall (pericarp), which encloses the solitary seed so closely as to seem like a seed coat. Examples The fruits of buttercup, buckwheat, caraway, quinoa, amaranth, and cannabis are typical achenes. The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an accessory fruit with an aggregate of achenes on its outer surface, and what is eaten is accessory tissue. A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium (aka f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head (botany)
A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers, or capitula, which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers (the florets) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large (as in the heads of some varieties of sunflower). Pseudanthia are characteristic of the daisy and sunflower family (Asteraceae), whose flowers are differentiated into ray flowers and disk flowers, unique to this family. The disk flowers in the center of the pseudanthium are actinomorphic and the corolla is fused into a tube. Flowers on the periphery are zygomorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis. The stalk of each flower in the inflorescence is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower and its stalk is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactuca Virosa
''Lactuca virosa'' is a plant in the ''Lactuca'' (lettuce) genus, often ingested for its mild analgesic and sedative effects. It is related to common lettuce ('' L. sativa''), and is often called wild lettuce, bitter lettuce, laitue vireuse, opium lettuce, poisonous lettuce, tall lettuce, great lettuce or rakutu-karyumu-so. Description ''Lactuca virosa'' is biennial, similar to prickly lettuce ''Lactuca serriola'' but taller – it can grow to 200 cm (80 inches or almost 7 feet). It is also stouter, the stem and leaves are more purple flushed, and the leaves are less divided, but more spreading, similarly to '' Mycelis muralis'' but showing more than 5 florets. The achene is purple black, without bristles at the tip. The pappus is the same as ''Lactuca serriola''. In the northern hemisphere, it flowers from July until September. Distribution Found coastally in Great Britain, rarely in north-east of Ireland. ''Lactuca virosa'' is widespread across much of central and sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactuca Saligna L
''Lactuca'', commonly known as lettuce, is a genus of flowering plants in the family Asteraceae. The genus includes at least 50 species, distributed worldwide, but mainly in temperate Eurasia. Its best-known representative is the garden lettuce (''Lactuca sativa''), with its many varieties. "Wild lettuce" commonly refers to the wild-growing relatives of common garden lettuce. Many species are common weeds. ''Lactuca'' species are diverse and take a wide variety of forms. They are annuals, biennials, perennials, or shrubs. Their flower heads have yellow, blue, or white ray florets. Some species are bitter-tasting. Most wild lettuces are xerophytes, adapted to dry habitat types. Some occur in more moist areas, such as the mountains of central Africa. Diversity There are different concepts of the species within ''Lactuca''. It is not clear how many distinct species are known, and estimates vary from 50 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taproot
A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot is a storage organ so well developed that it has been cultivated as a vegetable. The taproot system contrasts with the adventitious or fibrous root system of plants with many branched roots, but many plants that grow a taproot during germination go on to develop branching root structures, although some that rely on the main root for storage may retain the dominant taproot for centuries, for example ''Welwitschia''.Taproot also store nutrition. Plants with taproots are often vegetables. Description Dicots, one of the two divisions of flowering plants (angiosperms), start with a taproot, which is one main root forming from the enlarging radicle of the seed. The tap root can be persistent throughout the life of the plant but is most oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Plant
An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. The length of growing seasons and period in which they take place vary according to geographical location, and may not correspond to the four traditional seasonal divisions of the year. With respect to the traditional seasons, annual plants are generally categorized into summer annuals and winter annuals. Summer annuals germinate during spring or early summer and mature by autumn of the same year. Winter annuals germinate during the autumn and mature during the spring or summer of the following calendar year. One seed-to-seed life cycle for an annual plant can occur in as little as a month in some species, though most last several months. Oilseed rapa can go from seed-to-seed in about five weeks under a bank of fluorescent lamps. This style of growing is often used in classrooms for education. Many desert annuals are therophytes, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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