Ceanothus L. is a genus of about 50–60 species of nitrogen-fixing shrubs or small trees in the family Rhamnaceae. Common names for members of this genus are California lilac, wild lilac, soap bush. "Ceonothus" comes from a Greek word meaning "spiny plant", Ancient Greek: κεάνωθος, applied by Theophrastus to an Old World plant believed to be Cirsium arvense. The genus is endemic to North America, with the center of its distribution in California; some species are found in the eastern United States and southeast Canada, others extend as far south as Guatemala. Most are shrubs 0.5–3 metres tall, but C. arboreus and C. thyrsiflorus, both native to California, can be small multi-trunked trees up to 6–7 metres tall. There are two subgenera within this genus: Cerastes; the former clade is less drought-resistant. The evolution of these two clades started with a divergence in the niches filled in local communities, rather than a divergence on the basis of geography; the Californian species of Ceanothus are known collectively as California lilacs, with individual species having more descriptive common names.
Species native elsewhere have other common names, such as'New Jersey tea' for C. americanus, since its leaves were used as a black tea substitute during the American Revolution. In garden use, most are called by their scientific names or an adaptation of the scientific name, such as'Maritime ceanothus' for C. maritimus. The majority of the species are evergreen, but the handful of species adapted to cold winters are deciduous; the leaves are opposite or alternate, small and with serrated margins. Ceanothus leaves may be arranged opposite to alternate. Alternate leaves may have either three main veins rising from the base of the leaf; the leaves have a shiny upper surface that feels "gummy" when pinched between the thumb and forefinger, the roots of most species have red inner root bark. The flowers are white, greenish–white, dark purple-blue, pale purple or pink, maturing into a dry, three-lobed seed capsule; the flowers are tiny and produced in dense clusters. A few species are reported to be intensely fragrant to the point of being nauseating, are said to resemble the odor of "boiling honey in an enclosed area".
The seeds of this plant can lie dormant for hundreds of years, Ceanothus species are dependent on forest fires to trigger germination of their seeds. Fruits are hard, nutlike capsules. Plants in this genus are distributed and can be found on dry, sunny hillsides from coastal scrub lands to open forest clearings, from near sea level to 9,000 feet in elevation; these plants are profusely distributed throughout the Rocky Mountains from British Columbia south through Colorado, the Cascades of Oregon and California, the Coastal Ranges of California. Ceanothus velutinus is the most common member of this genus and is widespread through much of western North America; the plants in this genus co-occur with one another when they are more distantly related. Ceanothus is a good source of nutrition for deer mule deer on the West Coast of the United States. However, the leaves are not as nutritious from late spring to early fall as they are in early spring. Porcupines and quail have been seen eating stems and seeds of these shrubs.
The leaves are a good source of protein and the stems and leaves have been found to contain a high amount of calcium. Native Americans used the dried leaves of this plant as an herbal tea, early pioneers used the plant as a substitute for black tea. Miwok Indians of California made baskets from Ceanothus branches. C. integerrimus has been used by North American tribes to ease childbirth. Many Ceanothus species are popular ornamental plants for gardens. Dozens of hybrids and cultivars have been selected, such as flexible ceanothus, Ceanothus × flexilis; the following cultivars and hybrids have gained the Royal Horticultural Society's Award of Garden Merit: Other cultivars available include:- There are more cultivars and hybrids of Ceanothus arboreus, Ceanothus griseus horizontalis, Ceanothus thyrsiflorus in the nursery trade. Propagation of ceanothus is following scarification and stratification. Seeds are soaked in water for 12 hours followed by chilling at 1 °C for one to three months, it can sprout from roots and/or stems.
Seeds are stored in plant litter in large quantities. It is estimated. Seeds are dispersed propulsively from capsules and, it has been estimated, can remain viable for hundreds of years. In habitat, the seeds of plants in this genus germinate only in response to range fires and forest fires. Adolphia infesta Meisn. Colubrina arborescens Sarg. Colubrina asiatica Brongn. Colubrina elliptica Brizicky & W. L. Stern Noltea africana Endl. California chaparral and woodlands — ecoregion. Flora of the California chaparral and woodlands USDA Plants Profile for Ceanothus Calflora Database: Index of Ceanothus species native to California — with images + info links
The bamboos are evergreen perennial flowering plants in the subfamily Bambusoideae of the grass family Poaceae. The word "bamboo" comes from the Kannada term bambu, introduced to English through Indonesian and Malay. In bamboo, as in other grasses, the internodal regions of the stem are hollow and the vascular bundles in the cross-section are scattered throughout the stem instead of in a cylindrical arrangement; the dicotyledonous woody xylem is absent. The absence of secondary growth wood causes the stems of monocots, including the palms and large bamboos, to be columnar rather than tapering. Bamboos include some of the fastest-growing plants in the world, due to a unique rhizome-dependent system. Certain species of bamboo can grow 91 cm within a 24-hour period, at a rate of 4 cm an hour. Giant bamboos are the largest members of the grass family. Bamboos are of notable economic and cultural significance in South Asia, Southeast Asia and East Asia, being used for building materials, as a food source, as a versatile raw product.
Bamboo has a higher specific compressive strength than wood, brick or concrete, a specific tensile strength that rivals steel. Bamboos have long been considered the most primitive grasses because of the presence of bracteate, indeterminate inflorescences, "pseudospikelets", flowers with three lodicules, six stamens, three stigmata. Following more recent molecular phylogenetic research, many tribes and genera of grasses included in the Bambusoideae are now classified in other subfamilies, e.g. the Anomochlooideae, the Puelioideae, the Ehrhartoideae. The subfamily in its current sense belongs to the BOP clade of grasses, where it is sister to the Pooideae; the bamboos comprise three clades classified as tribes, these correspond with geographic divisions representing the New World herbaceous species, tropical woody bamboos, temperate woody bamboos. The woody bamboos do not form a monophyletic group. Altogether, more than 1,400 species are placed in 115 genera. Most bamboo species are native to moist tropical and warm temperate climates.
However, many species are found in diverse climates, ranging from hot tropical regions to cool mountainous regions and highland cloud forests. In the Asia-Pacific region they occur across East Asia, from north to 50 °N latitude in Sakhalin, to south to northern Australia, west to India and the Himalayas. China, Korea and Australia, all have several endemic populations, they occur in small numbers in sub-Saharan Africa, confined to tropical areas, from southern Senegal in the north to southern Mozambique and Madagascar in the south. In the Americas, bamboo has a native range from 47 °S in southern Argentina and the beech forests of central Chile, through the South American tropical rainforests, to the Andes in Ecuador near 4,300 m. Bamboo is native through Central America and Mexico, northward into the Southeastern United States. Canada and continental Europe are not known to have any native species of bamboo; as garden plants, many species grow outside these ranges, including most of Europe and the United States.
Some attempts have been made to grow bamboo on a commercial basis in the Great Lakes region of east-central Africa in Rwanda. In the United States, several companies are growing and distributing species such as Phyllostachys nigra and Phyllostachys edulis; the two general patterns for the growth of bamboo are "clumping" and "running". Clumping bamboo species tend to spread as the growth pattern of the rhizomes is to expand the root mass similar to ornamental grasses. "Running" bamboos, need to be controlled during cultivation because of their potential for aggressive behavior. They spread through their rhizomes, which can spread underground and send up new culms to break through the surface. Running bamboo species are variable in their tendency to spread; some can send out runners of several metres a year, while others can stay in the same general area for long periods. If neglected, over time, they can cause problems by moving into adjacent areas. Bamboos include some of the fastest-growing plants on Earth, with reported growth rates up to 91 cm in 24 hours.
However, the growth rate is dependent on local soil and climatic conditions, as well as species, a more typical growth rate for many cultivated bamboos in temperate climates is in the range of 3–10 cm per day during the growing period. Growing in regions of warmer climates during the late Cretaceous period, vast fields existed in what is now Asia; some of the largest timber bamboo can grow over 30 m tall, be as large as 25–30 cm in diameter. However, the size range for mature bamboo is species-dependent, with the smallest bamboos reaching only several inches high at maturity. A typical height range that would cover many of the common bamboos grown in the United States is 4.5–12 m, depending on species. Anji County of China, known as the "Town of Bamboo", provides the optimal climate and soil conditions to grow and process some of the most valued bamboo poles available worldwide. Unlike all trees, individual bamboo culms emerge from the ground at their full diameter and grow to their full height in a single growing season of three to four months.
During this time, each new shoot grows
A forb is an herbaceous flowering plant, not a graminoid. The term is used in biology and in vegetation ecology in relation to grasslands and understory. "Forb" is derived from the Greek φορβή, "pasture" or "fodder". The spelling "phorb" is sometimes used, in older usage this sometimes includes graminids and other plants not regarded as forbs. Forbs are members of a guild – a group of plant species with broadly similar growth form. In certain contexts in ecology, guild membership may be more important than the taxonomic relationships between organisms. In addition to its use in ecology, the term "forb" may be used for subdividing popular guides to wildflowers, distinguishing them from other categories such as grasses, sedges and trees; some examples of forbs are clover, sunflower and milkweed. Dicotyledon Herbaceous plant Overgrazing United States Department of Agriculture Natural Resources Conservation Service link to Growth habits Codes and Definitions
Forestry is the science and craft of creating, using and repairing forests and associated resources for human and environmental benefits. Forestry is practiced in natural stands; the science of forestry has elements that belong to the biological, social and managerial sciences. Modern forestry embraces a broad range of concerns, in what is known as multiple-use management, including the provision of timber, fuel wood, wildlife habitat, natural water quality management, recreation and community protection, aesthetically appealing landscapes, biodiversity management, watershed management, erosion control, preserving forests as "sinks" for atmospheric carbon dioxide. A practitioner of forestry is known as a forester. Other common terms are: a silviculturalist. Silviculture is narrower than forestry, being concerned only with forest plants, but is used synonymously with forestry. Forest ecosystems have come to be seen as the most important component of the biosphere, forestry has emerged as a vital applied science and technology.
Forestry is an important economic segment in various industrial countries. For example, in Germany, forests cover nearly a third of the land area, wood is the most important renewable resource, forestry supports more than a million jobs and about €181 billion of value to the German economy each year; the preindustrial age has been dubbed by Werner Sombart and others as the'wooden age', as timber and firewood were the basic resources for energy and housing. The development of modern forestry is connected with the rise of capitalism, economy as a science and varying notions of land use and property. Roman Latifundiae, large agricultural estates, were quite successful in maintaining the large supply of wood, necessary for the Roman Empire. Large deforestations came with after the decline of the Romans; however in the 5th century, monks in the Byzantine Romagna on the Adriatic coast, were able to establish stone pine plantations to provide fuelwood and food. This was the beginning of the massive forest mentioned by Dante Alighieri in his 1308 poem Divine Comedy.
Similar sustainable formal forestry practices were developed by the Visigoths in the 7th century when, faced with the ever-increasing shortage of wood, they instituted a code concerned with the preservation of oak and pine forests. The use and management of many forest resources has a long history in China as well, dating back to the Han dynasty and taking place under the landowning gentry. A similar approach was used in Japan, it was later written about by the Ming dynasty Chinese scholar Xu Guangqi. In Europe, land usage rights in medieval and early modern times allowed different users to access forests and pastures. Plant litter and resin extraction were important, as pitch was essential for the caulking of ships and hunting rights and building, timber gathering in wood pastures, for grazing animals in forests; the notion of "commons" refers to the underlying traditional legal term of common land. The idea of enclosed private property came about during modern times. However, most hunting rights were retained by members of the nobility which preserved the right of the nobility to access and use common land for recreation, like fox hunting.
Systematic management of forests for a sustainable yield of timber began in Portugal in the 13th century when Afonso III of Portugal planted the Pinhal do Rei near Leiria to prevent coastal erosion and soil degradation, as a sustainable source for timber used in naval construction. His successor Dom Dinis continued the forest exists still today. Forest management flourished in the German states in the 14th century, e.g. in Nuremberg, in 16th-century Japan. A forest was divided into specific sections and mapped; as timber rafting allowed for connecting large continental forests, as in south western Germany, via Main, Neckar and Rhine with the coastal cities and states, early modern forestry and remote trading were connected. Large firs in the black forest were called "Holländer ``. Large timber rafts on the Rhine were 200 to 400m in length, 40m in width and consisted of several thousand logs; the crew consisted of 400 to 500 men, including shelter, bakeries and livestock stables. Timber rafting infrastructure allowed for large interconnected networks all over continental Europe and is still of importance in Finland.
Starting with the sixteenth century, enhanced world maritime trade, a boom in housing construction in Europe and the success and further Berggeschrey of the mining industry increased timber consumption sharply. The notion of'Nachhaltigkeit', sustainability in forestry, is connected to the work of Hans Carl von Carlowitz, a mining administrator in Saxony, his book Sylvicultura oeconomica, oder haußwirthliche Nachricht und Naturmäßige Anweisung zur wilden Baum-Zucht was the first comprehensive treatise about sustainable yield forestry. In the UK, and, to an extent, in continental Europe, the enclosure movement and the clearances favored enclosed private property; the Agrarian reformers, early economic writers and scientists tried to get rid of the traditional commons. At the time, an alleged tragedy of the commons together with fears of a Holznot, an imminent wood shortage played a watershed role in the controversies about cooperative land use patterns; the practice of establishing tree plantations in the British Isles was promoted by John Evelyn, though it had acquired some populari
Close to nature forestry
Close to nature forestry is a management approach treating forest as an ecological system performing multiple functions. Close to nature silviculture tries to achieve the management objectives with minimum necessary human intervention aimed at accelerating the processes that nature would do by itself more slowly, it works with natural populations of trees, ongoing processes and existing structures using cognitive approach, as in the case of uneven-aged forest. Its theory and practice manages it as such, it aims at overcoming the divorce between ecologist management systems of forest. As an important consequence, it concludes that if properly applied, it would render the segregation of forest lands into "productive" and "reserves" or national parks unnecessary; the Arbeitsgemeinschaft für Naturgemässe Waldwirtschaft was established in Germany in 1950. In recent years this association has increased a lot its membership; the main reasons being the increase of ecological consciousness, the growing demand for forest products or services other than wood, the damages suffered by regular forest stands, the forest death fear.
Another term used to describe a close to nature approach to forest management in Britain and Ireland, is Continuous Cover Forestry. Because of a 1948 forest law, Slovenia has many forests managed according to the principles of close to nature forestry. In 1989 ANW promoted a meeting at Robanov Kot in Slovenia, in the Julian Alps, the Pro Silva organization was created, with representatives of 10 countries. At present the organization headquarters are in the French region of Alsace. In the United States, professor Thomas J. McEvoy has published the book Positive Impact Forestry, which recommends forestry practices similar to those of the "close to nature" movement, he thinks that the precursors of this type of forestry are to be found in Europe in Germany, makes mention of Heinrich Cotta, his famous Cotta's Preface, which highlighted the importance that the study and understanding of nature should have for the foresters. As a more immediate precursor he makes reference to ecologist Aldo Leopold.
The Ecoforestry Institute consists on educational, non profit and non governmental organizations operating in US and Canada. They propose a forestry based on ecological principles similar to those of Pro Silva; the close to nature approach intends to bridge the discrepancies, or antagonisms between the silvicultural and ecological visions on the single reality of forest, considering the forest as an ecological system that produces wood. The sought after solution is not to segregate the territory into areas devoted to either forestry or ecology, but to integrate all functions; the management has to obtain healthy and stable forest systems that produce wood with a minimum human intervention. The products to obtain, other than wood, are fauna habitats, recreational and water management; the human action has the object of accelerating natural processes. Pro Silva recommends to use the uneven-aged forest system, in which the ages, sizes, of trees in a forest are different, it has the advantage to offer a stable structure regarding natural disasters and plagues, is adequate for fauna habitat and biodiversity promotion.
It provides a better soil protection. McEvoy considers that in spite of being the most close to nature system, it is difficult to implement, proposes to use the high regular forest model, in which all trees are of the same age/size, but recommends using a regeneration system with a generous cover, to avoid soil erosion, prevent excessive light entrance, which would promote the growth of a potent understorey; the Ecoforestry Institute to Pro Silva, recommends multi-aged and multi-species forests. Proposed thinning frequency is about ten years, intensity low, in order to limit the ingress of excessive light, which could promote too much understory, or the growing of epicormic shoots, it has to be directed to favor the trees. The operations have to be done in a way that will avoid soil compaction or damage to the trees that will remain standing; when foresters plant trees, they may use either native or introduced species. Whenever foresters decide to use a species, not native, they do it because they think that there are silvicultural advantages linked to this choice, be they the wood quality, ease of management, adaptation to the climatic conditions, shorter production delay, etc.
It may be that there is information available about the behavior of this species in the habitat, or the forester is ready to make a trial. From the ecological point of view, the introducing species is considered as a threat; the introduced species risks being invasive. Invasives displace local species, resulting in a reduction of biodiversity, a condition to be expected if great extensions are forested using introduced species. McEvoy is clear and strict: introduced species can not be used at all when working in a close to nature forestry system. Pro Silva makes some distinctions, based on conditions. Natural forest systems are to be preserved, but the enrichment with certain introduced species may be positive, depending on circumstances. Pro Silva recommendations The natural vegetation systems for each region are an asset to maintain, constitute an important basis for the silvicultural planning. Introduced species can, depending on circumstances, supplement natural species, add economical revenue.
The forest species that are introduced to a region are termed exotic
Agroforestry is a land use management system in which trees or shrubs are grown around or among crops or pastureland. This intentional combination of agriculture and forestry has varied benefits, including increased biodiversity and reduced erosion. Agroforestry practices have been successful in parts of the United States; the theoretical base for agroforestry comes via agroecology. From this perspective, agroforestry is one of the three principal agricultural land-use sciences; the other two are forestry. Agroforestry shares principles with intercropping. Both place two or more plant species in close proximity and both provide multiple outputs; as a consequence, overall yields are higher and because a single application or input is shared, costs are reduced. Agroforestry systems can be advantageous over conventional agricultural, forest production methods, they can offer increased productivity, economic benefits, more diversity in the ecological goods and services provided. Depending upon the application, positive impacts of agroforestry comprise different topics.
Biodiversity in agroforestry systems is higher than in conventional agricultural systems. Two or more interacting plant species in a given area create a more complex habitat that can support a wider variety of fauna. Agroforestry is important for biodiversity for different reasons, it provides a more diverse habitat than a conventional agricultural system. Tropical bat and bird diversity for instance can be comparable to the diversity in natural forests. Although agroforestry systems do not provide as many floristic species as forests and do not show the same canopy height, they do provide food and nesting possibilities. A further contribution to biodiversity is; as agroforests have no natural clear areas, habitats are more uniform. Furthermore, agroforests can serve as corridors between habitats. Agroforestry can help to conserve biodiversity by having a positive influence on other ecosystem services. Depleted soils can be protected from soil erosion by groundcover plants such as growing grasses in agroforestry systems.
These help to stabilise the soil. Soil cover is a crucial factor in preventing erosion. Cleaner water through reduced nutrient and soil surface runoff can be a further advantage of agroforestry; the runoff can be reduced by increasing infiltration into the soil. Compared to row-cropped fields nutrient uptake can reduce nutrient loss into streams. Further advantages concerning plant growth: Bioremediation Drought resistance Increased crop stability Reduced poverty through increased production of wood and other products Increased food security by restored soil fertility for food crops Multifunctional site use, e.g. crop production and animal grazing Reduced global warming and hunger risk by increasing the number of drought-resistant trees and the subsequent production of fruits and edible oils Reduced deforestation and pressure on woodlands by providing farm-grown fuelwood Reduced need for toxic chemicals Improved human nutrition through more diverse farm outputs Growing space for medicinal plants e.g. in situations where people have limited access to mainstream medicines Carbon sequestration is an important ecosystem service.
Trees in agroforestry systems, like in new forests, can recapture some of the carbon, lost by cutting existing forests. They provide additional food and products; the rotation age and the use of the resulting products are important factors controlling the amount of carbon sequestered. Agroforests can reduce pressure on primary forests by providing forest products. Agroforestry practices may realize a number of associated environmental goals, such as: Odour and noise reduction Green space and visual aesthetics Enhancement or maintenance of wildlife habitat Especially in recent years, poor smallholder farmers turned to agroforestry as a mean to adapt to climate change. A study from the CGIAR research program on Climate Change and Food Security found from a survey of over 700 households in East Africa that at least 50% of those households had begun planting trees in a change from earlier practices; the trees were planted with fruit, coffee, oil and medicinal products in addition to their usual harvest.
Agroforestry was one of the most widespread adaptation strategies, along with the use of improved crop varieties and intercropping. Agroforestry encompasses diverse applications such as countering winds, high rainfall, harmful insects, etc; some categories are described in the following sections. A well-studied example of an agroforestry hillside system is the Quesungual Slash and Mulch Agroforestry System in Lempira Department, Honduras; this region was used for slash and burn subsistence agriculture. Due to heavy seasonal floods, the exposed soil was washed away, leaving infertile barren soil exposed to the dry season. Farmed hillside sites had to be abandoned; the Food and Agriculture Organization of the United Nations helped introduce a system incorporating local knowledge consisting of the following steps: Thin and prune Hillside secondary forest, leaving individual beneficial trees nitrogen-fixing trees. They help reduce soil erosion, maintain soil moisture, provide shade and provide an input of nitrogen-rich organic matter in the form of litter.
Plant maize in rows. This is a traditional local crop. Harvest from the dried plant and plant beans; the maize stalks provide an i
Manzanita is a common name for many species of the genus Arctostaphylos. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from Southern British Columbia and Washington to Oregon, Arizona, New Mexico and Texas in the United States, throughout Mexico. Manzanitas can live in places with little water, they are characterized by smooth orange or red bark and twisting branches. There are 105 species and subspecies of manzanita, 95 of which are found in the Mediterranean climate and colder mountainous regions of California, ranging from ground-hugging coastal and mountain species to small trees up to 20 feet tall. Manzanitas carry berries in spring and summer; the berries and flowers of most species are edible. The word manzanita is the Spanish diminutive of manzana. A literal translation would be little apple; the name manzanita is sometimes used to refer to species in the related genus Arbutus, known by that name in the Canadian area of the tree's range, but is more known as madroño, or madrone in the United States.
Native Americans in Northern California made a tisane from manzanita leaves to treat poison oak rash. The leaves contain chemicals with a mildly disinfectant quality, can be used for mild urinary tract infections; the berries are a good food, as they can be stored. Once stored and dried, the berries can be ground into a coarse meal; the berries can be eaten ripe or green for a sour taste. They are good used as a thickener or sweetener in other dishes. Fresh berries and branch tips can be soaked in water to make a cider. Native Americans used. Manzanitas are useful as ornamental plants in gardens in the western United States and similar climate zones, they are evergreen drought-tolerant, have picturesque bark and attractive flowers and berries, come in many sizes and growth patterns. Arctostaphylos columbiana, for example, is hardy enough to be used for highway landscaping in western Oregon and Washington. Arctostaphylos'Emerald Carpet', A. uva-ursi, other low-growing manzanitas are valuable evergreen groundcovers for dry slopes.
Larger varieties, such as Arctostaphylos.'Dr. Hurd,' can be grown as individual specimens, pruned to emphasize the striking pattern and colors of the branches, they prefer light, well-drained soil, although the low-growing ground covers will tolerate heavier soils. Manzanita branches are popular as decoration, due to their unique shape and strength when dried. Florists sometimes use them as centerpieces at wedding receptions and other events adding hanging votive candles, beaded gems and small flowers to them; the wood is notoriously hard to cure due to cracking against the grain, giving it few uses as lumber. The slow growth rate and many branchings further decrease the sizes available; some furniture and art employ whole round branches, which reduces cracking and preserves the deep red color. The dead wood decays and can last for many years, on and off the plant. Sunlight smooths and bleaches manzanita to light grey or white, rendering it superficially akin to animal bones; because of this and the stunted growth of many species, manzanita is collected in its more unusual shapes, giving it the nickname mountain driftwood.
Manzanita wood is used as perches for parrots and other large pet birds. The branches of the larger species are long-lasting for this purpose; some aquarium keepers use sandblasted manzanita as driftwood in planted aquaria because of its attractive forked growth and its chemical neutrality. If properly cleaned and cured, it holds up well over extended periods of submersion; the wood is resistant to the leaching of tannins into the water column, a problem found with other aquarium driftwoods. When used as driftwood, manzanita must be either weighted down for several weeks or soaked first to counteract the wood's natural buoyancy when it has been dried and cured; the green wood does not float. Manzanita wood, when dry, is excellent for burning in a campfire, fireplace, or stove, it burns at a high temperature for long periods. However, caution should be exercised, because the high temperatures can damage thin-walled barbecues, crack cast iron stoves or cause chimney fires. During World War II, Manzanita root burls were used as an expedient native material to make smoking pipes due to its relation and similar fire-resistant properties to then-unavailable imported briar.
Labeled as "Mission Briar", it was harvested for the remainder of the war, stopping soon after when supplies of imported briar once again became available. Some manzanita species are among the rarest plants in the world. Arctostaphylos hookeri ravenii, an endemic species, is the most endangered and restricted plant in the mainland United States. In 1987 only one specimen remained, at a secret location in the Presidio of San Francisco National Historic Landmark District in San Francisco, California; this plant has since been cloned. Arctostaphylos franciscana, a species native to San Francisco, had not been seen growing wild since 1947 until it was spotted growing in the Presidio of San Francisco in October 2009. Caltrans transplanted this specimen on 23 January 2010 to make way for the Doyle Drive Replacement Project. Transplanting costs were funded in part by Federal Highways Administration, The Presidio of San Francisco, private donors. "Arctostaphylos hookeri, subspecies franciscana", a scrubby, thin-twigged bush, riddled with the webs of miniature spiders, resides in a corner of