Arabidopsis thaliana, the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. A. thaliana is considered a weed. A winter annual with a short life cycle, A. thaliana is a popular model organism in plant biology and genetics. For a complex multicellular eukaryote, A. thaliana has a small genome of 135 megabase pairs. It was the first plant to have its genome sequenced, is a popular tool for understanding the molecular biology of many plant traits, including flower development and light sensing. Arabidopsis thaliana is an annual plant growing to 20–25 cm tall; the leaves form a rosette at the base of the plant, with a few leaves on the flowering stem. The basal leaves are green to purplish in color, 1.5–5 cm long and 2–10 mm broad, with an entire to coarsely serrated margin. Leaves are covered with small, unicellular hairs called trichomes; the flowers are 3 mm in diameter, arranged in a corymb. The fruit is a siliqua 5 -- 20 mm long. Roots are simple in structure, with a single primary root that grows vertically downward producing smaller lateral roots.
These roots form interactions with rhizosphere bacteria such as Bacillus megaterium. A. thaliana can complete its entire lifecycle in six weeks. The central stem that produces flowers grows after about three weeks, the flowers self-pollinate. In the lab, A. thaliana may be grown in Petri plates, pots, or hydroponics, under fluorescent lights or in a greenhouse. The plant was first described in 1577 in the Harz Mountains by Johannes Thal, a physician from Nordhausen, Thüringen, who called it Pilosella siliquosa. In 1753, Carl Linnaeus renamed the plant Arabis thaliana in honor of Thal. In 1842, the German botanist Gustav Heynhold erected the new genus Arabidopsis and placed the plant in that genus; the genus name, comes from Greek, meaning "resembling Arabis". Thousands of natural inbred accessions of A. thaliana have been collected from throughout its natural and introduced range. These accessions exhibit considerable genetic and phenotypic variation which can be used to study the adaptation of this species to different environments.
A. thaliana is native to Europe, Asia and human observations indicate its geographic distribution is rather continuous from the Mediterranean to Scandinavia and Spain to Greece. It appears to be native in tropical alpine ecosystems in Africa and South Africa, it has been introduced and naturalized worldwide, including in North America ca. the 17th century. A. Thaliana grows and pioneers rocky and calcareous soils, it is considered a weed, due to its widespread distribution in agricultural fields, railway lines, waste ground and other disturbed habitat, but due to its limited competitive ability and small size it is not categorized as a noxious weed. Like most Brassicaceae species, A. thaliana is edible by humans as a salad or cooked, but it does not enjoy a widespread use as a spring vegetable. Botanists and biologists began to research A. thaliana in the early 1900s, the first systematic description of mutants was done around 1945. A. thaliana is now used for studying plant sciences, including genetics, population genetics, plant development.
Although A. thaliana has little direct significance for agriculture, it has several traits that make it a useful model for understanding the genetic and molecular biology of flowering plants. The first mutant in A. thaliana was documented in 1873 by Alexander Braun, describing a double flower phenotype. However, not until 1943 did Friedrich Laibach propose A. thaliana as a model organism. His student, Erna Reinholz, published her thesis on A. thaliana in 1945, describing the first collection of A. thaliana mutants that they generated using X-ray mutagenesis. Laibach continued his important contributions to A. thaliana research by collecting a large number of accessions. With the help of Albert Kranz, these were organised into a large collection of 750 natural accessions of A. thaliana from around the world. In the 1950s and 1960s, John Langridge and George Rédei played an important role in establishing A. thaliana as a useful organism for biological laboratory experiments. Rédei wrote several scholarly reviews instrumental in introducing the model to the scientific community.
The start of the A. thaliana research community dates to a newsletter called Arabidopsis Information Service, established in 1964. The first International Arabidopsis Conference was held in Göttingen, Germany. In the 1980s, A. thaliana started to become used in plant research laboratories around the world. It was one of several candidates that included maize and tobacco; the latter two were attractive, since they were transformable with the then-current technologies, while maize was a well-established genetic model for plant biology. 1986 was a breakthrough year for A. thaliana as a model plant, in which T-DNA-mediated transformation and the first cloned A. thaliana gene were described. The small size of its genome, the fact that it is diploid, makes Arabidopsis thaliana useful for genetic mapping and sequencing — with about 135 mega base pairs and five chromosomes, A. thaliana has one of the smallest genomes among plants. It was long thought to have the smalles
Western Australia Day is a public holiday in Western Australia, celebrated on the first Monday in June each year to commemorate the founding of the Swan River Colony in 1829. Because of the celebration of Western Australia Day, WA does not celebrate the Queen's Birthday Holiday in June, as do the other Australian states. HMS Challenger, under Captain Charles Fremantle, anchored off Garden Island on 25 April 1829. Fremantle claimed the western part of Australia for Britain on 2 May; the merchant vessel Parmelia – with the new colony's administrator Lieutenant-Governor James Stirling, other officials, civilian settlers on board – arrived on the night of 31 May and sighted the coast on 1 June. It anchored in Cockburn Sound on 6 June; the warship HMS Sulphur arrived on 8 June. The Swan River Colony was proclaimed by Stirling on 11 June. Ships carrying more civilian settlers began arriving in August, on the King's birthday, 12 August, the wife of the captain of Sulphur, Mrs Helena Dance, standing in for Mrs Ellen Stirling, cut down a tree to mark the founding of the colony's capital, Perth.
In 1832, Stirling decided that an annual celebration was needed to unite the colony's inhabitants, including both settlers and Aborigines and "masters and servants". He decided that the commemoration would be held on 1 June each year, the date planned by Stirling for Parmelia's arrival in recognition of the first and greatest British naval victory over the French in 1794, the "Glorious First of June"; the holiday was celebrated as Foundation Day up until 2011.
Rocky Woods is a 491-acre open space preserve located in Medfield, Massachusetts. The preserve, managed by the land conservation non-profit organization The Trustees of Reservations, is notable for its rugged terrain. Rocky Woods offers 6.5 miles of trails and former woods roads available for hiking, horseback riding, mountain biking, dog walking and release fishing and cross country skiing. The preserve is part of a larger area of protected open space including the abutting Fork Factory Brook preserve managed by The Trustees of Reservations. Rocky Woods contains rugged, granite hills and knolls with occasional scenic vistas, boulder caves, rock formations, narrow ravines and defiles, glacial erratics, local boulders. Six pondlets are located on the property: Chickering Pond, Echo Pond, Notch Pond, June Pond, Little Chickering Pond, part of an unnamed sixth pond; the rugged, rocky terrain of Rocky Woods was formed via glacial action during the last ice age through glacial plucking and scouring.
During the colonial 18th century, Rocky Woods had been divided into common land woodlots. A network of logging roads, paved with asphalt shingle scraps, were cut through the property in the 19th century and used to transport granite quarried on site; the property was preserved by Dr. Joel Goldthwait in the 1920s, who donated the original parcels to The Trustees of the Reservations in 1942. Additional land acquired by other donors from 1946 through 1983 through more than ten gifts. Rocky Woods reservation in Medfield once had a rope tow ski area near Chickering Pond; the area had one steep slope, just a bit too steep for beginners. The area faced southwest, receiving lots of sun, which melted the snow quite often. Today, the area is growing in but is still visible, open to the public at Rocky Woods; the old rope tow lift line clearing is still visible today, located just north of the north end of Chickering Pond. A network of trails connect with the abutting Fork Factory Brook reservation; the property contains a number of scenic vistas.
Dog walking is permitted on selected trails with designated on- and off-leash zones. Swimming is prohibited. Preserve amenities include picnic tables and pavilion, off-street parking lots, restrooms. A visitor center offers canoe rentals, fishing gear, snowshoe rentals and small concessions on weekends. Rocky Woods shares a trailhead with Fork Factory Brook, located on Hartford Street in Medfield. Rocky Woods. TTOR. Retrieved December 29, 2008. Map of Rocky Woods and Fork Factory Brook; the Trustees of Reservations Fork Factory Brook Bay Circuit Trail Bay Circuit Trail Section 9 description Bay Circuit Trail Section 9 map Rocky Woods Ski History