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Toxicodendron Radicans
''Toxicodendron radicans'', commonly known as eastern poison ivy or poison ivy, is an allergenic Asian and Eastern North American flowering plant in the genus ''Toxicodendron''. The species is well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch it. The rash is caused by urushiol, a clear liquid compound in the plant's sap. The species is variable in its appearance and habit, and despite its common name, it is not a true ivy (''Hedera''), but rather a member of the cashew and pistachio family (Anacardiaceae). ''T. radicans'' is commonly eaten by many animals and the seeds are consumed by birds, but poison ivy is most often thought of as an unwelcome weed. It is a different species from western poison ivy, '' T. rydbergii'', which has similar effects. Description Numerous subspecies and/or varieties of ''T. radicans'' are known. They can be found growing in any of the following forms, all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ottawa
Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core of the Ottawa–Gatineau census metropolitan area (CMA) and the National Capital Region (NCR). Ottawa had a city population of 1,017,449 and a metropolitan population of 1,488,307, making it the fourth-largest city and fourth-largest metropolitan area in Canada. Ottawa is the political centre of Canada and headquarters to the federal government. The city houses numerous foreign embassies, key buildings, organizations, and institutions of Canada's government, including the Parliament of Canada, the Supreme Court, the residence of Canada's viceroy, and Office of the Prime Minister. Founded in 1826 as Bytown, and incorporated as Ottawa in 1855, its original boundaries were expanded through numerous annexations and were ultimately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of ''deciduous'' in the botanical sense is evergreen. Generally, the term "deciduous" means "the dropping of a part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans); or decidua, the uterine lining that sheds off after birth. Botany In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year. This process is called abscissio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries (polypyrenous drupes are exceptions). The definitive characteristic of a drupe is that the hard, lignified stone is derived from the ovary wall of the flower. In an aggregate fruit, which is composed of small, individual drupes (such as a raspberry), each individual is termed a drupelet, and may together form an aggregate fruit. Such fruits are often termed ''berries'', although botanists use a different definition of ''berry''. Other fleshy fruits may have a stony enclosure that comes from the seed coat surrounding the seed, but such fruits are not drupes. Flowering plants that produce drupes include coffee, jujube, mango, oli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is biparental reproduction. Dioecy has costs, since only about half the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility. Dioecy is a dimorphic sexual system, alongside gynodioecy and androdioecy. In zoology In zoology, dioecious species may be opposed to hermaphroditic species, meaning that an individual is either male or female, in which case the synonym gonochory is more often used. Most animal species are dioecious (gon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Sexuality
Plant reproductive morphology is the study of the physical form and structure (the Plant morphology, morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the reproductive structures of flowering plant, angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, Marchantiophyta, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetative Reproduction
Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules. Many plants naturally reproduce this way, but it can also be induced artificially. Horticulturists have developed asexual propagation techniques that use vegetative propagules to replicate plants. Success rates and difficulty of propagation vary greatly. Monocotyledons typically lack a vascular cambium, making them more challenging to propagate. Background Plant propagation is the process of plant reproduction of a species or cultivar, and it can be sexual or asexual. It can happen through the use of vegetative parts of the plants, such as leaves, stems, and roots to produce new plants or through growth from specialized vegetative plant parts. While m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Crown
A root crown, also known as the root collar or root neck, is that part of a root system from which a stem arises. Since roots and stems have quite different vascular The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ... anatomies, major vascular changes take place at this point. Root-crown temperature has been found to affect plant growth and physiology in a number of ways. Root crowns need to be exposed and 'breathe'; this is one way that some plants take in oxygen. A number of pests and diseases affect specifically this part of the plant, including root-crown rot (or root-crown fungus) and a number of species of root-crown weevil. The root crown area usually appears swollen, tapered, constricted or very thin - as well as a combination of these. The area of the root crown is usuall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizome
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards. A rhizome is the main stem of the plant that runs underground horizontally. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, and generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, and generate new upward-growing shoots from the top of the nodes. A stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, which is a modified stolon. The term "tuber" is often used imprecisely and is sometimes applied to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adventitious Roots
Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born (or hatches from its egg), it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification. According to plant physiologist A. Carl Leopold, the properties of organization seen in a plant are emergent properties which are more than the sum of the individual parts. "The assembly of these tissues and functions into an integrated multicellular organism yields not only the characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternate Leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autumn
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Southern Hemisphere). Autumn is the season when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December (Northern Hemisphere) and June (Southern Hemisphere). One of its main features in temperate climates is the striking change in colour for the leaves of deciduous trees as they prepare to shed. Date definitions Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat the equinox as the start of autumn. In the English-speaking world of high latitude countries, autumn traditionally began with Lammas Day and ended around Hallowe'en, the approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaflet (botany)
A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a leaf, petiole or a branch of the leaf. Compound leaves are common in many plant families and they differ widely in morphology (biology), morphology. The two main classes of compound leaf morphology are Leaf shape, palmate and pinnate. For example, a ''Cannabis, hemp'' plant has palmate compound leaves, whereas some species of ''Acacia sensu lato, Acacia'' have pinnate leaves. The ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf is called a pinnule or pinnula. Image:Ветвь акации.jpg, Pinnate leaf of a Fabaceae, legume with 10 leaflets Image:Mimosa Pudica.gif, ''Mimosa pudica'' folding leaflets inward. See also * Compound leaf References Plant morphology {{botany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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