|
Helianthus Nuttallii
''Helianthus nuttallii'', or Nuttall's sunflower, is a species of sunflower native to northern, central, and western North America, from Newfoundland west to British Columbia, south to Missouri, New Mexico, and California. ''Helianthus nuttallii'' is a herbaceous perennial plant growing to 50–400 cm (20-160 inches) tall. The leaves are opposite on the lower part of the stem, alternate higher up, narrow lanceolate, 8–20 cm (3.2-8.0 inches) long and 6–30 mm wide, with a rough texture. The flowers are yellow, produced in a flowerhead approximately 9 cm (3.6 inches) diameter with 10–20 ray florets and at least 60 disc florets; each stem bears one to a few flowerheads.Jepson Flora''Helianthus nuttallii''/ref>Plants of British Columbia''Helianthus nuttallii''/ref> Subspecies of ''Helianthus nuttallii'' include: * ''Helianthus nuttallii'' subsp. ''nuttallii'' - Canada, western United States. ''H. nuttallii'' subsp. ''nuttallii'' is considered by some to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Torrey
John Torrey (August 15, 1796 – March 10, 1873) was an American botanist, chemist, and physician. Throughout much of his career, he was a teacher of chemistry, often at multiple universities, while he also pursued botanical work, focusing on the flora of North America. His most renowned works include studies of the New York flora, the Mexican Boundary, the Pacific railroad surveys, and the uncompleted ''Flora of North America''. Biography Torrey was born in New York City, the second child of Capt. William and Margaret (née Nichols) Torrey.Robbins, C. C. (1968). John Torrey (1796–1873), His Life & Times. ''Bulletin of the Torrey Botanical Club''. Vol. 95, No. Nov. 6–Dec. 1968, 515–645. Torrey Botanical Club, New York. He showed a fondness for mechanics, and at one time planned to become a machinist. When he was 15 or 16, his father received an appointment to the state prison at Greenwich Village, New York, where he was tutored by Amos Eaton, then a prisoner a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helianthus Nuttallii Subsp
''Helianthus'' () is a genus comprising about 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of ''Helianthus'' are native to North America and Central America. The best-known species is the common sunflower (''Helianthus annuus''), whose round flower heads in combination with the ligules look like the Sun. This and other species, notably Jerusalem artichoke (''H. tuberosus''), are cultivated in temperate regions and some tropical regions, as food crops for humans, cattle, and poultry, and as ornamental plants. The species ''H. annuus'' typically grows during the summer and into early fall, with the peak growth season being mid-summer. Several perennial ''Helianthus'' species are grown in gardens, but have a tendency to spread rapidly and can become aggressive. On the other hand, the whorled sunflower, ''Helianthus verticillatus'', was listed as an endangered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disc Floret
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. Most species of Asteraceae are annual, biennial, or perennial herbaceous plants, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. The primary common characteristic is the existence of sometimes hundreds of tiny individual florets which are held together by protective involucres in flower heads, or more technical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray Florets
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. Most species of Asteraceae are annual, biennial, or perennial herbaceous plants, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. The primary common characteristic is the existence of sometimes hundreds of tiny individual florets which are held together by protective involucres in flower heads, or more technic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of spermatophyte, seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internode (botany), internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a Peduncle (botany), peduncle. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis. The stalk of each flower in the inflorescence is called a Pedicel (botany) , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are posi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perennial Plant
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth (secondary growth in girth) from trees and shrubs, which are also technically perennials. Perennialsespecially small flowering plantsthat grow and bloom over the spring and summer, die back every autumn and winter, and then return in the spring from their rootstock or other overwintering structure, are known as herbaceous perennials. However, depending on the rigours of local climate (temperature, moisture, organic content in the soil, microorganisms), a plant that is a perennial in its native habitat, or in a milder garden, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings, or from divisions. Tomato vines, for example, live several y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asa Gray
Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botanist of the 19th century. His ''Darwiniana'' was considered an important explanation of how religion and science were not necessarily mutually exclusive. Gray was adamant that a genetic connection must exist between all members of a species. He was also strongly opposed to the ideas of hybridization within one generation and special creation in the sense of its not allowing for evolution. He was a strong supporter of Darwin, although Gray's theistic evolution was guided by a Creator. As a professor of botany at Harvard University for several decades, Gray regularly visited, and corresponded with, many of the leading natural scientists of the era, including Charles Darwin, who held great regard for him. Gray made several trips to Europe to collaborate with leading European scientists of the era, as well as trips to the southern and western United States. He also built an extensive n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Leaf")
.jpg "Click for more on -> Extinct")
.jpg "Click for more on -> Endemism")
.jpg "Click for more on -> Asa Gray")