Xerophyte
A xerophyte is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic. Popular examples of xerophytes are cacti and some Gymnosperm plants; the structural features and fundamental chemical processes of xerophytes are variously adapted to conserve water common to store large quantities of water, during dry periods. Other species are able to survive long periods of extreme dryness or desiccation of their tissues, during which their metabolic activity may shut down. Plants with such morphological and physiological adaptations are xeromorphic. Xerophytes such as cacti are capable of withstanding extended periods of dry conditions as they have deep-spreading roots and capacity to store water; the leaves are thorny that prevents loss of water and moisture. Their fleshy stems can store water. Plants absorb water from the soil, which evaporates from their shoots and leaves. In dry environments, a typical mesophytic plant would evaporate water faster than the rate of water uptake from the soil, leading to wilting and death.
Xerophytic plants exhibit a diversity of specialized adaptations to survive in such water-limiting conditions. They may use water from their own storage, allocate water to sites of new tissue growth, or lose less water to the atmosphere and so channel a greater proportion of water from the soil to photosynthesis and growth. Different plant species possess different qualities and mechanisms to manage water supply, enabling them to survive. Cacti and other succulents are found in deserts, where there is little rainfall. Other xerophytes, such as certain bromeliads, can survive through both wet and dry periods and can be found in seasonally-moist habitats such as tropical forests, exploiting niches where water supplies are too intermittent for mesophytic plants to survive. Chaparral plants are adapted to Mediterranean climates, which have wet winters and dry summers. Plants that live under arctic conditions have a need for xerophytic adaptations, since water is unavailable for uptake when the ground is frozen, such as the European resurrection plants Haberlea rhodopensis and Ramonda serbica.
In an environment with high salinity such as mangrove swamps and semi-deserts, water uptake by plants is a challenge due to the high salt ion levels. Besides that, such environments may cause an excess of ions to accumulate in the cells, damaging. Halophytes and xerophytes evolved to survive in such environments; some xerophytes may be considered halophytes, halophytes are not xerophytes. The succulent xerophyte Zygophyllum xanthoxylum, for example, have specialised protein transporters in their cells which allow storage of excess ions in their vacuole to maintain normal cytosolic pH and ionic composition. There are many factors which affect water availability, the major limiting factor of seed germination, seedling survival, plant growth; these factors include infrequent raining, intense sunlight and warm weather leading to faster water evaporation. An extreme environmental pH and high salt content of water disrupt plants' water uptake. Succulent plants leaves; these include plants from the Cactaceae family, which have round can store a lot of water.
The leaves are vestigial, as in the case of cacti, wherein the leaves are reduced to spines, or they do not have leaves at all. These include the C4 perennial woody plant, Haloxylon ammodendron, a native of northwest China. Non-succulent perennials endure long and continuous shortage of water in the soil; these euxerophytes. Water deficiency reaches 60–70% of their fresh weight, as a result of which the growth process of the whole plant is hindered during cell elongation; the plants which survive drought are, understandably and weak. Ephemerals are the'drought escaping' kind, not true xerophytes, they do not endure drought, only escape it. With the onset of rainfall, the plant seeds germinate grow to maturity and set seed, i.e. the entire life cycle is completed before the soil dries out again. Most of these plants are small, dense shrubs represented by species of Papilionaceae, some inconspicuous Compositae, a few Zygophyllaceae and some grasses. Water is stored at below ground level, they may be dormant during drought conditions and are, known as drought evaders.
Shrubs which grow in arid and semi-arid regions are xeromorphic. For example, Caragana korshinskii, Artemisia sphaerocephala, Hedysarum scoparium are shrubs potent in the semi-arid regions of the northwest China desert; these psammophile shrubs are not only edible to grazing animals in the area, they play a vital role in the stabilisation of desert sand dunes. Bushes called semi-shrubs occur in sandy desert region in deep sandy soils at the edges of the dunes. One example is a perennial resurrection semi-shrub. Compared to other dominant arid xerophytes, an adult R. soongorica, bush has a strong resistance to water scarcity, hence, it is considered a super-xerophytes. If the water potential inside a leaf is higher than outside, the water vapour will diffuse out of the leaf down this gradient; this loss of water vapour from the leaves is called transpiration, the water vapour diffuses through the open stomata. Transpiration is inevitable for plants.
Eudicots
The eudicots, Eudicotidae or eudicotyledons are a clade of flowering plants, called tricolpates or non-magnoliid dicots by previous authors. The botanical terms were introduced in 1991 by evolutionary botanist James A. Doyle and paleobotanist Carol L. Hotton to emphasize the evolutionary divergence of tricolpate dicots from earlier, less specialized, dicots; the close relationships among flowering plants with tricolpate pollen grains was seen in morphological studies of shared derived characters. These plants have a distinct trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Molecular evidence confirmed the genetic basis for the evolutionary relationships among flowering plants with tricolpate pollen grains and dicotyledonous traits; the term means "true dicotyledons", as it contains the majority of plants that have been considered dicots and have characteristics of the dicots. The term "eudicots" has subsequently been adopted in botany to refer to one of the two largest clades of angiosperms, monocots being the other.
The remaining angiosperms include magnoliids and what are sometimes referred to as basal angiosperms or paleodicots, but these terms have not been or adopted, as they do not refer to a monophyletic group. The other name for the eudicots is tricolpates, a name which refers to the grooved structure of the pollen. Members of the group have tricolpate pollen; these pollens have three or more pores set in furrows called colpi. In contrast, most of the other seed plants produce monosulcate pollen, with a single pore set in a differently oriented groove called the sulcus; the name "tricolpates" is preferred by some botanists to avoid confusion with the dicots, a nonmonophyletic group. Numerous familiar plants are eudicots, including many common food plants and ornamentals; some common and familiar eudicots include members of the sunflower family such as the common dandelion, the forget-me-not and other members of its family, buttercup and macadamia. Most leafy trees of midlatitudes belong to eudicots, with notable exceptions being magnolias and tulip trees which belong to magnoliids, Ginkgo biloba, not an angiosperm.
The name "eudicots" is used in the APG system, of 1998, APG II system, of 2003, for classification of angiosperms. It is applied to a monophyletic group, which includes most of the dicots. "Tricolpate" is a synonym for the "Eudicot" monophyletic group, the "true dicotyledons". The number of pollen grain furrows or pores helps classify the flowering plants, with eudicots having three colpi, other groups having one sulcus. Pollen apertures are any modification of the wall of the pollen grain; these modifications include thinning and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. The elongated apertures/ furrows in the pollen grain are called colpi, along with pores, are a chief criterion for identifying the pollen classes; the eudicots can be divided into two groups: the basal eudicots and the core eudicots. Basal eudicot is an informal name for a paraphyletic group; the core eudicots are a monophyletic group.
A 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called "Pentapetalae", comprising all the remaining core eudicots. The Pentapetalae can be divided into three clades: Dilleniales superrosids consisting of Saxifragales and rosids superasterids consisting of Santalales, Berberidopsidales and asteridsThis division of the eudicots is shown in the following cladogram: The following is a more detailed breakdown according to APG IV, showing within each clade and orders: clade Eudicots order Ranunculales order Proteales order Trochodendrales order Buxales clade Core eudicots order Gunnerales order Dilleniales clade Superrosids order Saxifragales clade Rosids order Vitales clade Fabids order Fabales order Rosales order Fagales order Cucurbitales order Oxalidales order Malpighiales order Celastrales order Zygophyllales clade Malvids order Geraniales order Myrtales order Crossosomatales order Picramniales order Malvales order Brassicales order Huerteales order Sapindales clade Superasterids order Berberidopsidales order Santalales order Caryophyllales clade Asterids order Cornales order Ericales clade Campanulids order Aquifoliales order Asterales order Escalloniales order Bruniales order Apiales order Dipsacales order Paracryphiales clade Lamiids order Solanales order Lamiales order Vahliales order Gentianales order Boraginales order Garryales order Metteniusales order Icacinales Eudicots at the Encyclopedia of Life Eudicots, Tree of Life Web Project Dicots Plant Life Forms
Egypt
Egypt the Arab Republic of Egypt, is a country spanning the northeast corner of Africa and southwest corner of Asia by a land bridge formed by the Sinai Peninsula. Egypt is a Mediterranean country bordered by the Gaza Strip and Israel to the northeast, the Gulf of Aqaba and the Red Sea to the east, Sudan to the south, Libya to the west. Across the Gulf of Aqaba lies Jordan, across the Red Sea lies Saudi Arabia, across the Mediterranean lie Greece and Cyprus, although none share a land border with Egypt. Egypt has one of the longest histories of any country, tracing its heritage back to the 6th–4th millennia BCE. Considered a cradle of civilisation, Ancient Egypt saw some of the earliest developments of writing, urbanisation, organised religion and central government. Iconic monuments such as the Giza Necropolis and its Great Sphinx, as well the ruins of Memphis, Thebes and the Valley of the Kings, reflect this legacy and remain a significant focus of scientific and popular interest. Egypt's long and rich cultural heritage is an integral part of its national identity, which has endured, assimilated, various foreign influences, including Greek, Roman, Ottoman Turkish, Nubian.
Egypt was an early and important centre of Christianity, but was Islamised in the seventh century and remains a predominantly Muslim country, albeit with a significant Christian minority. From the 16th to the beginning of the 20th century, Egypt was ruled by foreign imperial powers: The Ottoman Empire and the British Empire. Modern Egypt dates back to 1922, when it gained nominal independence from the British Empire as a monarchy. However, British military occupation of Egypt continued, many Egyptians believed that the monarchy was an instrument of British colonialism. Following the 1952 revolution, Egypt expelled British soldiers and bureaucrats and ended British occupation, nationalized the British-held Suez Canal, exiled King Farouk and his family, declared itself a republic. In 1958 it merged with Syria to form the United Arab Republic, which dissolved in 1961. Throughout the second half of the 20th century, Egypt endured social and religious strife and political instability, fighting several armed conflicts with Israel in 1948, 1956, 1967 and 1973, occupying the Gaza Strip intermittently until 1967.
In 1978, Egypt signed the Camp David Accords withdrawing from the Gaza Strip and recognising Israel. The country continues to face challenges, from political unrest, including the recent 2011 revolution and its aftermath, to terrorism and economic underdevelopment. Egypt's current government is a presidential republic headed by President Abdel Fattah el-Sisi, described by a number of watchdogs as authoritarian. Islam is the official religion of Egypt and Arabic is its official language. With over 95 million inhabitants, Egypt is the most populous country in North Africa, the Middle East, the Arab world, the third-most populous in Africa, the fifteenth-most populous in the world; the great majority of its people live near the banks of the Nile River, an area of about 40,000 square kilometres, where the only arable land is found. The large regions of the Sahara desert, which constitute most of Egypt's territory, are sparsely inhabited. About half of Egypt's residents live in urban areas, with most spread across the densely populated centres of greater Cairo and other major cities in the Nile Delta.
The sovereign state of Egypt is a transcontinental country considered to be a regional power in North Africa, the Middle East and the Muslim world, a middle power worldwide. Egypt's economy is one of the largest and most diversified in the Middle East, is projected to become one of the largest in the world in the 21st century. In 2016, Egypt became Africa's second largest economy. Egypt is a founding member of the United Nations, Non-Aligned Movement, Arab League, African Union, Organisation of Islamic Cooperation. "Miṣr" is the Classical Quranic Arabic and modern official name of Egypt, while "Maṣr" is the local pronunciation in Egyptian Arabic. The name is of Semitic origin, directly cognate with other Semitic words for Egypt such as the Hebrew "מִצְרַיִם"; the oldest attestation of this name for Egypt is the Akkadian "mi-iṣ-ru" related to miṣru/miṣirru/miṣaru, meaning "border" or "frontier". There is evidence of rock carvings in desert oases. In the 10th millennium BCE, a culture of hunter-gatherers and fishers was replaced by a grain-grinding culture.
Climate changes or overgrazing around 8000 BCE began to desiccate the pastoral lands of Egypt, forming the Sahara. Early tribal peoples migrated to the Nile River where they developed a settled agricultural economy and more centralised society. By about 6000 BCE, a Neolithic culture rooted in the Nile Valley. During the Neolithic era, several predynastic cultures developed independently in Upper and Lower Egypt; the Badarian culture and the successor Naqada series are regarded as precursors to dynastic Egypt. The earliest known Lower Egyptian site, predates the Badarian by about seven hundred years. Contemporaneous Lower Egyptian communities coexisted with their southern counterparts for more than two thousand years, remaining culturally distinct, but maintaining frequent contact through trade; the earliest known evidence of Egyptian hieroglyphic inscriptions appeared during the predynastic period on Naqada III pottery vessels, dated to about 3200 BCE. A unified kingdom was founded c. 3150 BCE
Flowering plant
The flowering plants known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, the production of fruits that contain the seeds. Etymologically, angiosperm means a plant; the term comes from the Greek words sperma. The ancestors of flowering plants diverged from gymnosperms in the Triassic Period, 245 to 202 million years ago, the first flowering plants are known from 160 mya, they diversified extensively during the Early Cretaceous, became widespread by 120 mya, replaced conifers as the dominant trees from 100 to 60 mya. Angiosperms differ from other seed plants in several ways, described in the table below; these distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans.
Angiosperm stems are made up of seven layers. The amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms; the vascular bundles of the stem are arranged such that the phloem form concentric rings. In the dicotyledons, the bundles in the young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles, a complete ring is formed, a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside; the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
Among the monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They once formed the stem increases in diameter only in exceptional cases; the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, provide the most trustworthy external characteristics for establishing relationships among angiosperm species; the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally from the axil of a leaf; as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. More the flower-bearing portion of the plant is distinguished from the foliage-bearing or vegetative portion, forms a more or less elaborate branch-system called an inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens.
The "female" cells called megaspores, which will divide to become the egg cell, are contained in the ovule and enclosed in the carpel. The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators; the individual members of these surrounding structures are known as petals. The outer series is green and leaf-like, functions to protect the rest of the flower the bud; the inner series is, in general, white or brightly colored, is more delicate in structure. It functions to attract bird pollinators. Attraction is effected by color and nectar, which may be secreted in some part of the flower; the characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or hermaphrodite, flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization.
Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot transfer pollen to the pistil. Homomorphic flowers may employ a biochemical mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers; the botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon and σπέρμα, was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked; the term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any
Anatolia
Anatolia known as Asia Minor, Asian Turkey, the Anatolian peninsula or the Anatolian plateau, is the westernmost protrusion of Asia, which makes up the majority of modern-day Turkey. The region is bounded by the Black Sea to the north, the Mediterranean Sea to the south, the Armenian Highlands to the east and the Aegean Sea to the west; the Sea of Marmara forms a connection between the Black and Aegean Seas through the Bosphorus and Dardanelles straits and separates Anatolia from Thrace on the European mainland. The eastern border of Anatolia is traditionally held to be a line between the Gulf of Alexandretta and the Black Sea, bounded by the Armenian Highland to the east and Mesopotamia to the southeast. Thus, traditionally Anatolia is the territory that comprises the western two-thirds of the Asian part of Turkey. Nowadays, Anatolia is often considered to be synonymous with Asian Turkey, which comprises the entire country. By some definitions, the area called the Armenian highlands lies beyond the boundary of the Anatolian plateau.
The official name of this inland region is the Eastern Anatolia Region. The ancient inhabitants of Anatolia spoke the now-extinct Anatolian languages, which were replaced by the Greek language starting from classical antiquity and during the Hellenistic and Byzantine periods. Major Anatolian languages included Hittite and Lydian among other more poorly attested relatives; the Turkification of Anatolia began under the Seljuk Empire in the late 11th century and continued under the Ottoman Empire between the late 13th and early 20th centuries. However, various non-Turkic languages continue to be spoken by minorities in Anatolia today, including Kurdish, Neo-Aramaic, Arabic, Laz and Greek. Other ancient peoples in the region included Galatians, Assyrians, Cimmerians, as well as Ionian and Aeolian Greeks. Traditionally, Anatolia is considered to extend in the east to an indefinite line running from the Gulf of Alexandretta to the Black Sea, coterminous with the Anatolian Plateau; this traditional geographical definition is used, for example, in the latest edition of Merriam-Webster's Geographical Dictionary, Under this definition, Anatolia is bounded to the east by the Armenian Highlands, the Euphrates before that river bends to the southeast to enter Mesopotamia.
To the southeast, it is bounded by the ranges that separate it from the Orontes valley in Syria and the Mesopotamian plain. Following the Armenian genocide, Ottoman Armenia was renamed "Eastern Anatolia" by the newly established Turkish government. Vazken Davidian terms the expanded use of "Anatolia" to apply to territory referred to as Armenia an "ahistorical imposition", notes that a growing body of literature is uncomfortable with referring to the Ottoman East as "Eastern Anatolia". Most archeological sources consider the boundary of Anatolia to be Turkey's eastern border; the highest mountains in "Eastern Anatolia" are Mount Ararat. The Euphrates, Araxes and Murat rivers connect the Armenian plateau to the South Caucasus and the Upper Euphrates Valley. Along with the Çoruh, these rivers are the longest in "Eastern Anatolia"; the oldest known reference to Anatolia – as “Land of the Hatti” – appears on Mesopotamian cuneiform tablets from the period of the Akkadian Empire. The first recorded name the Greeks used for the Anatolian peninsula, Ἀσία echoed the name of the Assuwa league in western Anatolia.
As the name "Asia" broadened its scope to apply to other areas east of the Mediterranean, Greeks in Late Antiquity came to use the name Μικρὰ Ἀσία or Asia Minor, meaning "Lesser Asia" to refer to present-day Anatolia. The English-language name Anatolia itself derives from the Greek ἀνατολή meaning “the East” or more “sunrise”; the precise reference of this term has varied over time originally referring to the Aeolian and Dorian colonies on the west coast of Asia Minor. In the Byzantine Empire, the Anatolic Theme was a theme covering the western and central parts of Turkey's present-day Central Anatolia Region; the term "Anatolia" is Medieval Latin. The modern Turkish form of Anatolia, derives from the Greek name Aνατολή; the Russian male name Anatoly and the French Anatole share the same linguistic origin. The term "Anatolia" referred to a northwestern Byzantine province. By the 12th century Europeans had started referring to Anatolia as Turchia, it has also been called "Asia Minor". In earlier times, it was called" Rûm" by the Seljuqs.
During the era of the Ottoman Empire mapmakers outside the Empire referred to the mountainous plateau in eastern Anatolia as Armenia. Other contemporary sources called the same area Kurdistan. Geographers have variously used the terms east Anatolian plateau and Armenian plateau to refer to the region, although the territory encompassed by each term overlaps with the other. According to archaeologist Lori Khatchadourian this difference in terminology "primarily result from the shifting political fortunes and cultural trajectories of the region since the nineteenth century."Turkey's First Geography Congress in 1941 created two regions to the east of the Gulf of Iskenderun-Black Sea line named the Eastern Anatolia Region and the Southeastern Anatolia Region, the former corresponding to the weste
Weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place". Examples are plants unwanted in human-controlled settings, such as farm fields, gardens and parks. Taxonomically, the term "weed" has no botanical significance, because a plant, a weed in one context is not a weed when growing in a situation where it is in fact wanted, where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed, such as a wild bramble growing among cultivated loganberries. In the same way, volunteer crops are regarded as weeds in a subsequent crop. Many plants that people regard as weeds are intentionally grown in gardens and other cultivated settings, in which case they are sometimes called beneficial weeds; the term weed is applied to any plant that grows or reproduces aggressively, or is invasive outside its native habitat. More broadly "weed" is applied pejoratively to species outside the plant kingdom, species that can survive in diverse environments and reproduce quickly.
Weed control is important in agriculture. Methods include hand cultivation with hoes, powered cultivation with cultivators, smothering with mulch, lethal wilting with high heat, burning, or chemical attack with herbicides. Certain classes of weeds share adaptations to ruderal environments; that is to say: disturbed environments where soil or natural vegetative cover has been damaged or gets damaged, disturbances that give the weeds advantages over desirable crops, pastures, or ornamental plants. The nature of the habitat and its disturbances will affect or determine which types of weed communities become dominant. Examples of such ruderal or pioneer species include plants that are adapted to occurring disturbed environments such as dunes and other windswept areas with shifting soils, alluvial flood plains, river banks and deltas, areas that are burned repeatedly. Since human agricultural practices mimic these natural environments where weedy species have evolved, some weeds are preadapted to grow and proliferate in human-disturbed areas such as agricultural fields, lawns and construction sites.
The weedy nature of these species gives them an advantage over more desirable crop species because they grow and reproduce they have seeds that persist in the soil seed bank for many years, or they may have short lifespans with multiple generations in the same growing season. In contrast, perennial weeds have underground stems that spread under the soil surface or, like ground ivy, have creeping stems that root and spread out over the ground; some plants become dominant when introduced into new environments because the animals in their original environment, that compete with them or feed on them are absent. An example is Klamath weed, that threatened millions of hectares of prime grain and grazing land in North America after it was accidentally introduced, but was reduced to a rare roadside weed within several years after some of its natural enemies were imported during World War II. In locations where predation and mutually competitive relationships are absent, weeds have increased resources available for growth and reproduction.
The weediness of some species that are introduced into new environments may be caused by their production of allelopathic chemicals which indigenous plants are not yet adapted to, a scenario sometimes called the "novel weapons hypothesis". These chemicals may limit the growth of established plants or the germination and growth of seeds and seedlings. Another of the ways in which the ecological role of a plant can make it a weed if it is in itself inoffensive, is if it harbours a pest, dependent on it for survival. A number of native or non-native plants are unwanted in a specific location for a number of reasons. An important one is that they interfere with food and fiber production in agriculture, wherein they must be controlled in order to prevent lost or diminished crop yields. Other important reasons are that they interfere with other cosmetic, decorative, or recreational goals, such as in lawns, landscape architecture, playing fields, golf courses, they can be of concern for environmental reasons whereby introduced species out-compete for resources or space with desired endemic plants.
For all these reasons. In weed ecology some authorities speak of the relationship between "the three Ps": plant, perception; these have been variously defined, but the weed traits listed by H. G. Ba
Crete
Crete is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia and Corsica. Crete and a number of surrounding islands and islets constitute the region of Crete, one of the 13 top-level administrative units of Greece; the capital and the largest city is Heraklion. As of 2011, the region had a population of 623,065. Crete forms a significant part of the economy and cultural heritage of Greece, while retaining its own local cultural traits, it was once the centre of the Minoan civilisation, the earliest known civilisation in Europe. The palace of Knossos lies in Crete; the island is first referred to as Kaptara in texts from the Syrian city of Mari dating from the 18th century BC, repeated in Neo-Assyrian records and the Bible. It was known in ancient Egyptian as Keftiu suggesting a similar Minoan name for the island; the current name of Crete is thought to be first attested in Mycenaean Greek texts written in Linear B, through the words ke-re-te, ke-re-si-jo, "Cretan".
In Ancient Greek, the name Crete first appears in Homer's Odyssey. Its etymology is unknown. One proposal derives it from a hypothetical Luwian word, *kursatta. In Latin, it became Creta; the original Arabic name of Crete was Iqrīṭiš, but after the Emirate of Crete's establishment of its new capital at ربض الخندق Rabḍ al-Ḫandaq, both the city and the island became known as Χάνδαξ or Χάνδακας, which gave Latin and Venetian Candia, from which were derived French Candie and English Candy or Candia. Under Ottoman rule, in Ottoman Turkish, Crete was called Girit. Crete is the fifth largest island in the Mediterranean Sea, it is located in the southern part of the Aegean Sea separating the Aegean from the Libyan Sea. The island has an elongated shape: it spans 260 km from east to west, is 60 km at its widest point, narrows to as little as 12 km. Crete covers an area of 8,336 km2, with a coastline of 1,046 km, it lies 160 km south of the Greek mainland. Crete is mountainous, its character is defined by a high mountain range crossing from west to east, formed by three different groups of mountains: The White Mountains or Lefka Ori 2,454 m The Idi Range (Psiloritis 35.18°N 24.82°E / 35.18.
The island has a number of gorges, such as the Samariá Gorge, Imbros Gorge, Kourtaliotiko Gorge, Ha Gorge, Platania Gorge, the Gorge of the Dead and Richtis Gorge and waterfall at Exo Mouliana in Sitia. The rivers of Crete include the Ieropotamos River, the Koiliaris, the Anapodiaris, the Almiros, the Giofyros, Megas Potamos. There are only two freshwater lakes in Crete: Lake Kournas and Lake Agia, which are both in Chania regional unit. Lake Voulismeni at the coast, at Aghios Nikolaos, was a freshwater lake but is now connected to the sea, in Lasithi. Lakes that were created by dams exist in Crete. There are three: the lake of Aposelemis Dam, the lake of Potamos Dam, the lake of Mpramiana Dam. A large number of islands and rocks hug the coast of Crete. Many are visited by tourists, some are only visited by biologists; some are environmentally protected. A small sample of the islands includes: Gramvousa the pirate island opposite the Balo lagoon Elafonisi, which commemorates a shipwreck and an Ottoman massacre Chrysi island, which hosts the largest natural Lebanon cedar forest in Europe Paximadia island where the god Apollo and the goddess Artemis were born The Venetian fort and leper colony at Spinalonga opposite the beach and shallow waters of Elounda Dionysades islands which are in an environmentally protected region together the Palm Beach Forest of Vai in the municipality of Sitia, LasithiOff the south coast, the island of Gavdos is located 26 nautical miles south of Hora Sfakion and is the southernmost point of Europe.
Crete straddles two climatic zones, the Mediterranean and the North African falling within the former. As such, the climate in Crete is Mediterranean; the atmosphere can be quite humid, depending on the proximity to the sea, while winter is mild. Snowfall is rare in the low-lying areas. While some mountain tops are snow-capped for most of the year, near the coast snow only stays on the ground for a few minutes or hours. However, a exceptional cold snap swept the island in February 2004, during which period the whole island was blanketed with snow. During the Cretan summer, average temperatures reach the high 20s-low 30s Celsius, with maxima touching the upper 30s-mid 40s; the south coast, including the Mesara Pla
