Boophone is a small genus of herbaceous and bulbous plants in the Amaryllis family It consists of two confirmed species distributed across South Africa to Kenya and Uganda. It is related to Crossyne, a genus whose species have prostrate leaves, they are drought tolerant but not cold-hardy, are poisonous to livestock. Boophone is the single genus in subtribe Boophoninae, in the Amaryllideae tribe. Boophoninae are placed within Amaryllideae as follows, based on their phylogenetic relationship: The list of Boophone species, with their complete scientific name and geographic distribution is given below. William Herbert wrote the name of this genus with three different orthographies: "Boophane" in 1821. Several authors since speculated about the etymology and associated orthography of each name, but a proposal was published in 2001 to conserve the first name and to take the ones as synonyms; this proposal was accepted in 2002. Larvae of the moth genera Brithys and Diaphone use Boophone as a food plant.
Boophone disticha is used in South African traditional medicine by the Zulus to induce hallucinations for divinatory purposes, for various mental illnesses. Its use, however, is limited by injuries, they have been used as ingredients in traditional arrow poisons, medicinal dressings for skin lesions. A variety of alkaloids with affinity for the serotonin transporter have been isolated from Boophone disticha
Decussation is used in biological contexts to describe a crossing. The anatomical term chiasma is named after the Greek uppercase'Χ', chi). Examples include: In the brain, where nerve fibers obliquely cross from one lateral part to the other, to say they cross at a level other than their origin. See for examples Decussation of pyramids and sensory decussation. Decussation describes the point where the nerves cross from one side of the brain to the other, the nerves from the left side of the body decussate to the right side of the brain and the nerves from the right side of the body decussate to the left brain, however depending on the function of the nerves the level of decussation is variable. In neuroanatomy the term chiasma is reserved for the crossing of nerves outside the brain, such as the optic chiasm. In botanical leaf taxology, the word decussate describes an opposite pattern of leaves which has successive pairs at right angles to each other. In effect, successive pairs of leaves cross each other.
Basil is a classic example of a decussate leaf pattern. In tooth enamel, where bundles of rods cross each other as they travel from the enamel-dentine junction to the outer enamel surface, or near to it. In taxonomic description where decussate markings or structures occur, names such as decussatus or decussata or otherwise in part containing "decuss..." are common in the specific epithet. The origin of the contralateral organization, the optic chiasm and the major decussations on the nervous system of vertebrates has been a long standing puzzle to scientists. For long the visual map theory of Ramón y Cajal has been the most popular theory. More scientists have realized that this theory has some severe flaws. According to the current theory, the decussations are caused by an axial twist which makes it so that the anterior head, along with the forebrain, is turned by 180° with respect to the rest of the body. Commissure Why does the nervous system decussate?: Stanford Neuroblog Media related to Decussation at Wikimedia Commons
Lithops is a genus of succulent plants in the ice plant family, Aizoaceae. Members of the genus are native to southern Africa; the name is derived from the Ancient Greek words λίθος, meaning "stone," and ὄψ, meaning "face," referring to the stone-like appearance of the plants. They avoid being eaten by blending in with surrounding rocks and are known as pebble plants or living stones; the formation of the name from the Greek "-ops" means that a single plant is called a Lithops. Individual Lithops plants consist of one or more pairs of bulbous fused leaves opposite to each other and hardly any stem; the slit between the leaves produces flowers and new leaves. The leaves of Lithops are buried below the surface of the soil, with a or translucent top surface known as a leaf window which allows light to enter the interior of the leaves for photosynthesis. During winter a new leaf pair, or more than one, grows inside the existing fused leaf pair. In spring the old leaf pair parts to reveal the new leaves and the old leaves will dry up.
Lithops leaves may disappear below ground level during drought. Lithops in habitat never have more than one leaf pair per head as an adaptation to the arid environment. Yellow or white flowers emerge from the fissure between the leaves after the new leaf pair has matured, one per leaf pair; this is in autumn, but can be before the summer solstice in L. pseudotruncatella and after the winter solstice in L. optica. The flowers are sweetly scented; the most startling adaptation of Lithops is the colouring of the leaves. The leaves are fenestrated, the epidermal windows are patterned in various shades of cream and brown, with darker windowed areas and red lines, according to species and local conditions; the markings function as remarkable camouflage for the plant in its typical stone-like environment. As is typical of a window plant, the green tissue lines the inside of the leaves and is covered with translucent tissue beneath the epidermal windows. Lithops are obligate require pollination from a separate plant.
Like most mesembs, Lithops fruit is a dry capsule. Capsules may sometimes detach and be distributed intact, or may disintegrate after several years. Lithops occur across wide areas of Namibia and South Africa, as well as small bordering areas in Botswana and Angola, from sea level to high mountains. Nearly a thousand individual populations are documented, each covering just a small area of dry grassland, veld, or bare rocky ground. Different Lithops species are preferentially found in particular environments restricted to a particular type of rock. Lithops have not naturalised outside this region. Rainfall in Lithops habitats ranges from 700 mm/year to near zero. Rainfall patterns range from summer rain to winter rain, with a few species relying entirely on dew formation for moisture. Temperatures are hot in summer and cool to cold in winter, but one species is found right at the coast with moderate temperatures year round. Lithops are popular many specialist succulent growers maintain collections.
Seeds and plants are available in shops and over the Internet. They are easy to grow if given sufficient sun and a suitable well-drained soil. Normal treatment in mild temperate climates is to keep them dry during winter, watering only when the old leaves have dried up and been replaced by a new leaf pair. Watering continues through autumn when the plants flower and stopped for winter; the best results are obtained with additional heat such as a greenhouse. In hotter climates Lithops will have a summer dormancy when they should be kept dry, they may require some water in winter. In tropical climates, Lithops can be grown in winter with a long summer dormancy. In all conditions, Lithops will be most active and need most water during autumn and each species will flower at the same time. Lithops thrive best in a well-drained substrate. Any soil that retains too much water will cause the plants to burst their skins. Plants grown in strong light will develop hard coloured skins which are resistant to damage and rot, although persistent overwatering will still be fatal.
Excessive heat will kill potted plants as they cannot cool themselves by transpiration and rely on staying buried in cool soil below the surface. Commercial growers mix a mild fungicide or weak strength horticultural sulfur into the plants water to prevent rotting. Lithops are sensitive to watering during hot weather. Low light levels will make the plants susceptible to rotting and fungal infection. In the United Kingdom the following species have gained the Royal Horticultural Society’s Award of Garden Merit:- Propagation of Lithops is by seed or cuttings. Cuttings can only be used to produce new plants after a plant has divided to form multiple heads, so most propagation is by seed. Lithops can be pollinated by hand if two separate clones of a species flower at the same time, seed will be ripe about 9 months later. Seed is easy to germinate, but the seedlings are small and vulnerable for the first year or two, will not flower until at least two or three years old; the first scientific description of a Lithops was made by botanist and artist William J
Willows called sallows and osiers, form the genus Salix, around 400 species of deciduous trees and shrubs, found on moist soils in cold and temperate regions of the Northern Hemisphere. Most species are known as willow, but some narrow-leaved shrub species are called osier, some broader-leaved species are referred to as sallow; some willows are creeping shrubs. Willows all have abundant watery bark sap, charged with salicylic acid, soft pliant, tough wood, slender branches, large, fibrous stoloniferous roots; the roots are remarkable for their toughness and tenacity to live, roots sprout from aerial parts of the plant. The leaves are elongated, but may be round to oval with serrated edges. Most species are deciduous. All the buds are lateral; the buds are covered by a single scale. The bud scale is fused into a cap-like shape, but in some species it wraps around and the edges overlap; the leaves are simple, feather-veined, linear-lanceolate. They are serrate, rounded at base, acute or acuminate; the leaf petioles are short, the stipules very conspicuous, resembling tiny, round leaves, sometimes remaining for half the summer.
On some species, they are small and caducous. In color, the leaves show a great variety of greens. Willows are dioecious, with male and female flowers appearing as catkins on separate plants; the staminate flowers are without either calyx with corolla. This scale is square and hairy; the anthers are orange or purple after the flower opens. The filaments are threadlike pale brown, bald; the pistillate flowers are without calyx or corolla, consist of a single ovary accompanied by a small, flat nectar gland and inserted on the base of a scale, borne on the rachis of a catkin. The ovary is one-celled, the style two-lobed, the ovules numerous. All willows take root readily from cuttings or where broken branches lie on the ground; the few exceptions include the goat peachleaf willow. One famous example of such growth from cuttings involves the poet Alexander Pope, who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk; this twig was planted and thrived, legend has it that all of England's weeping willows are descended from this first one.
Willows are planted on the borders of streams so their interlacing roots may protect the bank against the action of the water. The roots are much larger than the stem which grows from them. Willows have a wide natural distribution from the tropics to the arctic zones and are extensively cultivated around the world. Willows are cross-compatible, numerous hybrids occur, both and in cultivation. A well-known ornamental example is the weeping willow, a hybrid of Peking willow from China and white willow from Europe; the hybrid cultivar'Boydii' has gained the Royal Horticultural Society's Award of Garden Merit. Numerous cultivars of Salix L. have been named over the centuries. New selections of cultivars with superior technical and ornamental characteristics have been chosen deliberately and applied to various purposes. Most Salix has become an important source for bioenergy production and for various ecosystem services; the first edition of the Checklist for Cultivars of Salix L. was compiled in 2015, which includes 854 cultivar epithets with accompanying information.
The International Poplar Commission of the FAO UN holds the International Cultivar Registration Authority for the genus Salix. The ICRA for Salix produces and maintains The International Register of Cultivars of Salix L.. Willows are used as food plants by the larvae of some Lepidoptera species, such as the mourning cloak butterfly. Ants, such as wood ants, are common on willows inhabited by aphids, coming to collect aphid honeydew, as sometimes do wasps. A small number of willow species were planted in Australia, notably as erosion-control measures along watercourses, they are now regarded as invasive weeds which occupy extensive areas across southern Australia and are considered'Weeds of National Significance'. Many catchment management authorities are replacing them with native trees. Substantial research undertaken from 2006 has identified that willows inhabit an unoccupied niche when they spread across the bed of shallow creeks and streams and if removed, there is a potential water saving of up to 500 ML/per year per hectare of willow canopy area, depending on willow species and climate zone.
This water could benefit the environment or provision of local water resources during dry periods. To aid management of willows, a remote sensing method has been developed to map willow area along and in streams a
Conophytum is a genus of South African and Namibian succulent plants that belong to the Aizoaceae family. The name is derived from Greek phytum; the plants are known as knopies, sphaeroids, cone plants, dumplings, or button plants. The genus is sometimes wrongly referred to as Conophyton, the name that Adrian Hardy Haworth suggested in 1821: "If this section proves to be a genus, the name of Conophyton would be apt". However, this was too tentative to establish a validly published generic name and Haworth himself neither adopted it nor accepted the genus; the genus was neither recognised nor validly named until the name Conophytum was published 101 years later. Conophytum species are dwarf single-bodied succulents. Members of the genus are tiny plants with succulent leaves ranging from 1/4" to 2" in length; these leaves are or fused along their centers. Each leaf pair ranges in shape from "bilobed" to spherical to ovoid to tubular to conical; some species have epidermal windows on the top of their leaves.
To the naked eye the epidermis ranges from smooth to rough to hairy, depending on the microscopic epidermal cell shape and structure. In their normal, natural state each stem has only one pair of leaves at a time though one plant may have dozens of stems and thus dozens of leaf pairs; when heavy rains come to their native habitat they may grow luxuriantly and develop two leaf pairs per stem simultaneously. Several species of Conophytum are found in cultivation. In temperate regions they are best grown in a specialist medium with the protection of glass, as they do not tolerate temperatures below 0 °C; this is a list of species in the genus Conophytum
Aloe written Aloë, is a genus containing over 500 species of flowering succulent plants. The most known species is Aloe vera, or "true aloe", so called because it is cultivated as the standard source of so-called "aloe vera" for assorted pharmaceutical purposes. Other species, such as Aloe ferox are cultivated or harvested from the wild for similar applications; the APG IV system places the genus in the family Asphodelaceae, subfamily Asphodeloideae. Within the subfamily it may be placed in the tribe Aloeae. In the past, it has been assigned to the family Aloaceae or to a broadly circumscribed family Liliaceae; the plant Agave americana, sometimes called "American aloe", belongs to the Asparagaceae, a different family. The genus is native to tropical and southern Africa, Jordan, the Arabian Peninsula, various islands in the Indian Ocean. A few species have become naturalized in other regions. Most Aloe species have a rosette of large, fleshy leaves. Aloe flowers are tubular yellow, pink, or red, are borne, densely clustered and pendant, at the apex of simple or branched, leafless stems.
Many species of Aloe appear to be stemless, with the rosette growing directly at ground level. They are sometimes striped or mottled; some aloes native to South Africa are tree-like. The APG IV system places the genus in the family Asphodelaceae, subfamily Asphodeloideae. In the past it has been assigned to the families Liliaceae and Aloeaceae, as well as the family Asphodelaceae sensu stricto, before this was merged into the Asphodelaceae sensu lato; the circumscription of the genus has varied widely. Many genera, such as Lomatophyllum, have been brought into synonymy. Species at one time placed in Aloe, such as Agave americana, have been moved to other genera. Molecular phylogenetic studies from 2010 onwards, suggested that as circumscribed, Aloe was not monophyletic and should be divided into more defined genera. In 2014, John Charles Manning and coworkers produced a phylogeny in which Aloe was divided into six genera: Aloidendron, Aloiampelos, Aloe and Gonialoe. Over 500 species are accepted in the genus Aloe, plus more synonyms and unresolved species, subspecies and hybrids.
Some of the accepted species are: In addition to the species and hybrids between species within the genus, several hybrids with other genera have been created in cultivation, such as between Aloe and Gasteria, between Aloe and Astroloba. Aloe species are cultivated as ornamental plants both in gardens and in pots. Many aloe species are decorative and are valued by collectors of succulents. Aloe vera is used both internally and externally on humans as alternative medicine; the plants can be made into types of special soaps or used in other skin care products. Numerous cultivars with mixed or uncertain parentage are grown. Of these, Aloe ‘Lizard Lips’ has gained the Royal Horticultural Society’s Award of Garden Merit. Historical use of various aloe species is well documented. Documentation of the clinical effectiveness is available, although limited. Of the 500+ species, only a few were used traditionally as herbal medicines, Aloe vera again being the most used species. Included are A. perryi and A. ferox.
The Ancient Greeks and Romans used Aloe vera to treat wounds. In the Middle Ages, the yellowish liquid found inside the leaves was favored as a purgative. Unprocessed aloe that contains aloin is used as a laxative, whereas processed juice does not contain significant aloin; some species Aloe vera, are used in alternative medicine and first aid. Both the translucent inner pulp and the resinous yellow aloin from wounding the aloe plant are used externally for skin discomforts; as an herbal medicine, Aloe vera juice is used internally for digestive discomfort. According to Cancer Research UK, a deadly product called T-UP is made of concentrated aloe, promoted as a cancer cure, they say "there is no evidence that aloe products can help to prevent or treat cancer in humans". On May 9, 2002, the US Food and Drug Administration issued a final rule banning the use of aloin, the yellow sap of the aloe plant, for use as a laxative ingredient in over-the-counter drug products. Most aloe juices today do not contain significant aloin.
According to W. A. Shenstone, two classes of aloins are recognized: nataloins, which yield picric and oxalic acids with nitric acid, do not give a red coloration with nitric acid; this second group may be divided into a-barbaloins, obtained from Barbados Aloe, reddened in the cold, b-barbaloins, obtained from Aloe Socotrina and Zanzibar Aloe, reddened by ordinary nitric acid only when warmed or by fuming acid in the cold. Nataloin forms bright-yellow scales, barbaloin prismatic crystals. Aloe species contain a trace of volatile oil, to which their odour is due. Aloe perryi, A. barbadensis, A. ferox, hybrids of this species with A. africana and A. spicata are listed as natural flavoring substances in the US government Electronic Code of Federal Regulations. Aloe socotrina is said to be used in yellow Chartreuse. Aloe rubrolutea occurs as a charge in heraldry
Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar and cottonwood. In the September 2006 issue of Science Magazine, the Joint Genome Institute announced that the western balsam poplar was the first tree whose full DNA code had been determined by DNA sequencing; the genus has a large genetic diversity, can grow from 15–50 m tall, with trunks up to 2.5 m in diameter. The bark on young trees is smooth, white to greenish or dark grey, has conspicuous lenticels; the shoots are stout, with the terminal bud present. The leaves are spirally arranged, vary in shape from triangular to circular or lobed, with a long petiole. Leaf size is variable on a single tree with small leaves on side shoots, large leaves on strong-growing lead shoots; the leaves turn bright gold to yellow before they fall during autumn. The flowers are dioecious and appear in early spring before the leaves.
They are borne in long, sessile or pedunculate catkins produced from buds formed in the axils of the leaves of the previous year. The flowers are each seated in a cup-shaped disk, borne on the base of a scale, itself attached to the rachis of the catkin; the scales are obovate and fringed, hairy or smooth, caducous. The male flowers are without calyx or corolla, comprise a group of four to 60 stamens inserted on a disk; the female flower has no calyx or corolla, comprises a single-celled ovary seated in a cup-shaped disk. The style is short, with two to four stigmata, variously lobed, numerous ovules. Pollination is by wind, with the female catkins lengthening between pollination and maturity; the fruit is a two- to four-valved dehiscent capsule, green to reddish-brown, mature in midsummer, containing numerous minute light brown seeds surrounded by tufts of long, white hairs which aid wind dispersal. Poplars of the cottonwood section are wetlands or riparian trees; the aspens are among the most important boreal broadleaf trees.
Poplars and aspens are important food plants for the larvae of a large number of Lepidoptera species. Pleurotus populinus, the aspen oyster mushroom, is found on dead wood of Populus trees in North America. Several species of Populus in the United Kingdom and other parts of Europe have experienced heavy dieback; the genus Populus has traditionally been divided into six sections on the basis of leaf and flower characters. Recent genetic studies have supported this, confirming some suspected reticulate evolution due to past hybridisation and introgression events between the groups; some species had differing relationships indicated by their nuclear DNA and chloroplast DNA sequences, a clear indication of hybrid origin. Hybridisation continues to be common in the genus, with several hybrids between species in different sections known. Populus section Populus – aspens and white poplar Populus adenopoda – Chinese aspen Populus alba – white poplar Populus × canescens – grey poplar Populus spp. X – Pacific albus Populus davidiana – Korean aspen Populus grandidentata – bigtooth aspen Populus sieboldii – Japanese aspen Populus tremula – aspen, common aspen, Eurasian aspen, European aspen, quaking aspen Populus tremuloides – quaking aspen or trembling aspen Populus section Aigeiros – black poplars, some of the cottonwoods Populus deltoides – eastern cottonwood Populus fremontii – Fremont cottonwood Populus nigra – black poplar, placed here by nuclear DNA.
Populus Populus × canadensis – hybrid black poplar Populus × inopina – hybrid black poplar Populus section Tacamahaca – balsam poplars Populus angustifolia – willow-leaved poplar or narrowleaf cottonwood Populus balsamifera – Balsam poplar Populus cathayana – Populus koreana J. Rehnder – Korean poplar Populus laurifolia – laurel-leaf poplar Populus maximowiczii A. Henry – Maximowicz' poplar, Japanese poplar Populus simonii – Simon's poplar Populus suaveolens Fischer – Mongolian poplar Populus szechuanica – Sichuan poplar, placed here by nuclear DNA. Aigeiros Populus trichocarpa – western balsam poplar or black cottonwood Populus tristis, placed here by nuclear DNA.