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Psathyrotes Ramosissima
''Psathyrotes ramosissima'' is a species of flowering plant in the aster family known by the common name velvet turtleback, or turtleback. It is native to the southwestern United States where it grows in desert scrub habitat. It is a low, neatly mounded plant producing spreading stems which are hairless to densely woolly in texture. Leaves are borne on long petioles. The leaf blade is variable in shape, generally roughly rounded, and up to 2 centimeters long. It has a wavy, bluntly toothed edge and a bumpy, velvety surface coated in woolly fibers and shiny hairs. It is brownish to gray-green to very pale green in color. The knobby inflorescence is lined with woolly gray-green phyllaries with dull points that curve outward. It contains several hairy yellow disc florets. The fruit is an achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Torrey
John Torrey (August 15, 1796 – March 10, 1873) was an American botany, 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 pri ... [...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 ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteraceae
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 technicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves with a petiole are said to be petiolate, while leaves lacking a petiole are called sessile or apetiolate. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, or short. When completely absent, the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant groups, such as the speedwell genus '' Veronica'', petiolate and sessile leaves may occur in different species. In the grasses (Poaceae), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the 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. 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. A flower that is not part of an inflorescence is called a solitary flower and its stalk is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate and ebracteolate, without bracts. Variants Some bracts are brightly-coloured and serve the function of attracting pollinators, either together with the perianth or instead of it. Examples of this type of bract include those of ''Euphorbia pulcherrima'' (poinsettia) and ''Bougainvillea'': both of these have large colourful bracts surrounding much smaller, less colourful flowers. In grasses, each floret (flower) is enclosed in a pair of papery bracts, called the lemma (lower bract) and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not open at maturity). Achenes contain a single seed that nearly fills the pericarp, but does not adhere to it. In many species, what is called the "seed" is an achene, a fruit containing the seed. The seed-like appearance is owed to the hardening of the fruit wall (pericarp), which encloses the solitary seed so closely as to seem like a seed coat. Examples The fruits of buttercup, buckwheat, caraway, quinoa, amaranth, and cannabis are typical achenes. The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an accessory fruit with an aggregate of achenes on its outer surface, and what is eaten is accessory tissue. A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium (aka f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pappus (flower Structure)
In Asteraceae, the pappus is the modified calyx, the part of an individual floret, that surrounds the base of the corolla tube in flower. It functions as a wind-dispersal mechanism for the seeds. The term is sometimes used for similar structures in other plant families e.g. in certain genera of the Apocynaceae, although the pappus in Apocynaceae is not derived from the calyx of the flower. In Asteraceae, the pappus may be composed of bristles (sometimes feathery), awns, scales, or may be absent, and in some species, is too small to see without magnification. In genera such as ''Taraxacum'' or ''Eupatorium'', feathery bristles of the pappus function as a "parachute" which enables the seed to be carried by the wind. The name derives from the Ancient Greek word ''pappos'', Latin ''pappus'', meaning "old man", so used for a plant (assumed to be an ''Erigeron'' species) having bristles and also for the woolly, hairy seed of certain plants. The pappus of the dandelion plays a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtleback Psathyrotes Ramosissima Small
''Psathyrotes'' is a genus of North American plants in the sneezeweed tribe within the sunflower family. It contains annual and perennial forbs and low subshrubs native to dry areas of southwestern North America. Common names include turtleback, brittlestem, and fanleaf. The plants are low, densely branching, hairy, and scaly, with a turpentine-like odor. Leaves are alternate and hairy. The Latin name of the genus (from the Greek ''psathurotes'') refers to the brittleness of the stems. ;Species * ''Psathyrotes annua'' (Nutt.) Gray (annual psathyrotes, mealy rosettes, turtleback) - CA NV UT AZ ID ** Synonyms: ''Bulbostylis annua'' Nutt. ** Annual or perennial forb * ''Psathyrotes pilifera'' Gray (hairy-beast turtleback, hairybeast brittlestem) - NV UT AZ ** Annual forb * ''Psathyrotes ramosissima'' (Torr.) Gray (velvet rosette, velvet turtleback, turtleback) - NV UT AZ CA, Baja California, Sonora ** Synonyms: ''Tetradymia ramosissima'' Torr. ** Annual or perennial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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