Layia discoidea is a rare species of flowering plant in the daisy family known by the common name rayless tidytips, or rayless layia.
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Senecio aphanactis, known by the common names chaparral ragwort, rayless ragwort, and California groundsel, is a species of flowering plant in the aster family.
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Helianthus radula is a North American species of sunflower known by the common name rayless sunflower or pineland sunflower.Flora of North America, Helianthus radula (Pursh) Torrey & A. Gray, 1842. Rayless or pineland sunflower It is native to the southeastern United States from eastern Louisiana to South Carolina.Biota of North America Program 2014 county distribution map Helianthus radula grows in sandy, open woodlands such as pine barrens.
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Arnica discoidea is a North American species of arnica in the sunflower family. It is known by the common name rayless arnica because its flower heads have disc florets but none of the showier ray florets.Calflora taxon report, University of California, Arnica discoidea Benth. rayless arnica It is native to the woodlands, forests, and chaparral of the western United States (Washington, Oregon, California, and western Nevada (Washoe County).
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The rayless form is yellow. The plant flowers well into autumn and hence provides a valuable source of nectar for late-flying butterflies such as painted lady and red admiral.
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Flora of North America Vol. 21 Page 375 Rayless arnica Arnica discoidea Bentham, Pl. Hartw. 319. 1849. The fruit is an achene about 7 millimeters long, not counting its light-colored pappus.
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Brintonia is a monotypic genus of flowering plants in the sunflower family, containing the single species Brintonia discoidea, named for Jeremiah Bernard Brinton. It is known commonly as the rayless mock goldenrod.Brintonia. Astereae Lab. University of Waterloo.
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Eucephalus tomentellus is a North American species of flowering plant in the aster family known by the common name Brickellbush aster or rayless aster. It grows on openings in oak or conifer forests the Siskiyou Mountains of the US States of California and Oregon.Biota of North America Program 2014 county distribution mapCalflora taxon report, University of California, Eucephalus tomentellus (Greene) Greene, rayless aster Eucephalus tomentellus is a perennial herb up to 90 cm (3 feet) tall, with a woody caudex. Stems are covered with woolly or cottony hair.
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Lasthenia glaberrima is a species of flowering plant in the daisy family known by the common names smooth goldfields and rayless goldfields. It is native to western North America from British Columbia to California, where it grows in wet places such as vernal pools and springtime meadows.
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Agnorhiza invenusta (syn. Wyethia invenusta) is a species of flowering plant known by the common names Coville's mule's ears and rayless mule's ears. It is found only in California, where it grows in the Sierra Nevada foothills as in Fresno, Tulare, and Kern Counties.Calflora taxon report, Wyethia invenusta (E.
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Lesions have been found on tuna that are consistent with cavitation damage. Scombrid fishes (tuna, mackerel and bonito) are particularly high-performance swimmers. Along the margin at the rear of their bodies is a line of small rayless, non-retractable fins, known as finlets. There has been much speculation about the function of these finlets.
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The flowers bloom from July to August, and are magenta colored with reddish-brown bracts. Each flower is from 4-7 inches long and 1/2 inches across, with 30-60 disk florets. They have central stout stem that is covered with white hairs. The flowers grow close to each other and have rayless heads.
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The lower leaves have stalks, whereas the upper leaves are attached directly to the stem. The flower heads are cylindrical and usually have 8 to 15 yellow ray florets ("petals") although some are rayless. The ray florets vary in length but are most commonly 4 to 7 mm long. The pollen grains are 30 to 36 micrometres across and usually have 4 pores.
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Open clusters of 10 to 22 small cylinder shaped rayless yellow flower heads to inch (6 to 13 mm) with a highly conspicuous ring of black tipped bracts at the base of the inflorescence as is characteristic of many members of the genus Senecio. There is a radiate form of Senecio vulgaris, which is the result of cross pollination with the closely related Oxford ragwort, Senecio squalidus.
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Packera indecora is a species of flowering plant in the aster family known by the common names elegant groundsel and rayless mountain ragwort. It is native to northern North America including most of Canada and sections of the northernmost United States. It grows in moist mountain habitat, such as streamsides and meadows. It is a perennial herb producing a single stem or a cluster of 2 or 3 stems from a branching caudex and a taproot.
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Tremetone is a chemical compound found in tremetol, a toxin mixture from snakeroot (Ageratina altissima) that causes milk sickness in humans and trembles in livestock. Tremetone is the main constituent of at least 11 chemically related substances in tremetol. Tremetone is toxic to fish, but not to chicken, and is therefore not the major toxic compound in tremetol. Tremetol can be found in a number of different species of the family Asteraceae, including snakeroot and rayless goldenrod (Isocoma pluriflora).
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A form with rayless flowers is sometimes considered a distinct species. Grindelia squarrosa, also known as a curly-top gumweed or curlycup gumweed, is a small North American biennial or short-lived perennial plant. It is native to western and central North America, from British Columbia east to Québec and New England, and south as far as California, New Mexico, Arizona, Chihuahua, and Texas. The species may possibly be naturalized in much of the eastern part of that distribution.
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Senecio aronicoides is a species of flowering plant in the aster family known by the common name rayless ragwort. It is native to Oregon and northern and central California, where it can be found in the woodlands and forests of mountains and foothills, often in relatively dry habitat. It is a biennial or perennial herb growing up to about 90 centimeters tall from a fleshy root attached to a buttonlike caudex. The plant is often slightly woolly or cobwebby in texture.
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Scombrid fishes (tuna, mackerel and bonito) are particularly high-performance swimmers. Along the margin at the rear of their bodies is a line of small rayless, non- retractable fins, known as finlets. There has been much speculation about the function of these finlets. Research done in 2000 and 2001 by Nauen and Lauder indicated that "the finlets have a hydrodynamic effect on local flow during steady swimming" and that "the most posterior finlet is oriented to redirect flow into the developing tail vortex, which may increase thrust produced by the tail of swimming mackerel".
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Bigelowia nuttallii (Nuttall's rayless goldenrod) is a species of North American flowering plants in the daisy family, native to the southern United States (Texas, Louisiana, Alabama, Georgia, and Florida).Biota of North America Program 2014 county distribution map Bigelowia nuttallii is a sub- shrub up to 70 cm (28 inches) tall, often forming clumps. Most of the leaves are in a rosette near the ground, with smaller and narrower leaves on the stems. Flower heads are small, yellow, and displayed in flat-topped arrays, each with 2-6 disc florets but no ray florets.
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The marbled swamp eel, Synbranchus marmoratus, has been recorded at up to in length, while the Bombay swamp eel, Monopterus indicus, reaches no more than . Swamp eels are almost entirely finless; the pectoral and pelvic fins are absent, the dorsal and anal fins are vestigial, reduced to rayless ridges, and the caudal fin ranges from small to absent, depending on species. Almost all of the species lack scales. The eyes are small, and in some cave-dwelling species, they are beneath the skin, so the fish is blind.
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Ericameria discoidea, called whitestem goldenbush or sharp-scale goldenweed or whitestem goldenbush or sharp-scale goldenweed, is a species of flowering shrub in the daisy family known by the common name whitestem goldenbush. This plant is native to the western United States from California, Oregon, Nevada, Utah, Colorado, Idaho, and Montana.Biota of North America Program 2014 county distribution mapCalflora taxon report, University of California, Ericameria discoidea (Nutt.) G. Nesom, rayless goldenbush, whitestem goldenbush Ericameria discoidea grows in clumpy thickets on rocky slopes. It is a small shrub reaching a maximum height of 40 centimeters (16 inches).
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The World Register of Marine Species lists 44 marine genera and species named after him with the epithet nuttalli.Species with the epithet nuttalli Various plants and birds were named after Nuttall, including Nuttall's woodpecker Dryobates nuttallii by his friend William Gambel, and yellow-billed magpie Pica nuttalli and common poorwill Phalaenoptilus nuttallii by John James Audubon.Richard and Barbara Mearns - Audubon to Xantus He is also commemorated in the Pacific dogwood Cornus nuttallii, Nuttall's larkspur, Nuttall's oak Quercus texana, the catclaw briar Mimosa nuttallii, Nuttall's violet Viola nuttallii, Nuttall's saltbush Atriplex nuttallii, and Nuttall's rayless goldenrod Bigelowia nuttallii. The Nuttall Ornithological Club of Cambridge, Massachusetts, is named after him.
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Tripolium pannonicum, called sea aster or seashore aster and often known by the synonyms Aster tripolium or Aster pannonicus, is a flowering plant, native to Eurasia and northern Africa, that is confined in its distribution to salt marshes, estuaries and occasionally to inland salt works. It is a perennial growing up to 50 cm tall with fleshy lanceolate leaves and purple ray florets flowering from July to September. The plants tend to be short-lived and populations need significant new recruitment each year from new seedlings. There are rayed as well as rayless varieties and only the former have long blue or white florets.
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The same min-max theorem can be generalized to infinite graphs of finite treewidth, with a definition of treewidth in which the underlying tree is required to be rayless (that is, having no ends). Havens are also closely related to the existence of separators, small sets X of vertices in an n-vertex graph such that every X-flap has at most 2n/3 vertices. If a graph G does not have a k-vertex separator, then every set X of at most k vertices has a (unique) X-flap with more than 2n/3 vertices. In this case, G has a haven of order , in which β(X) is defined to be this unique large X-flap.
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