nomes no trilho de navegação
There are a number of characteristics which can be summarized regarding the Dudleya genus. Genus occurrences are restricted to southwest North America; in fact, according to Low, approximately 98 percent of genus occurrences are along or near the coasts of Baja California, (the states of Baja Sur and Baja Norte in Mexico), plus the northward extension into the USA in the states of California and southern Oregon. A small number of genus populations are found in Arizona and possibly Nevada. The center of genus diversity is the coastal region where Mexico and the USA meet. Dudleyas have a strong affinity for the coastal regions, but some species have ranges that extend into the nearby mountains and deserts.
Most species of Dudleya grow at elevations near sea level, but a few grow on or even atop mountains of Baja California, the high Sierra Nevada and in many other California mountain ranges. Many, such as D.cymosa, prefer canyon locations on vertical or near vertical rocky walls, often in the shade, surviving in very little soil in the crevices of almost solid rock. Sometimes the occurrences are in locations that receive no direct sunlight. Almost all Dudleya species have succulent leaves arranged into rosettes. Because of this rosette geometry many genus members are striking in their visual appeal. Many, including the Canyon Liveforever, have leaves that are glaucous (covered with a whitish or bluish waxy coating) or frosty looking.
The chromosome count of all Dudleya species is n=17, with about 35% of all populations consisting of polyploids (individuals with multiples of the base number). Remarkably, according to extensive crossing experiments conducted by Verity, all Dudleya taxa are capable of hybridizing in nature.
There are eight recognized subspecies of D. cymosa (flower color in parentheses):
Dudleya (lat. Dudleya) — daşdələnçiçəklilər sırasının dovşankələmikimilər fəsiləsinə aid bitki cinsi.
Dudleya (lat. Dudleya) — daşdələnçiçəklilər sırasının dovşankələmikimilər fəsiləsinə aid bitki cinsi.
Stenurt (Dudleya) er en slægt med ca. 45 arter, som er udbredt i det sydvestlige Nordamerika. Det er sukkulente stauder med en grundstillet roset af tykke, grå eller grågrønne blade. Blomsterne bæres på høje stængler, som ender i en stor stand. Der er 5 af både bægerblade og kronblade, og de er sammenvoksede forneden. Der er fem støvfang og 10 støvdragere.
ArterDudleya ist eine Pflanzengattung aus der Familie der Dickblattgewächse (Crassulaceae). Der botanische Name der Gattung ehrt den US-amerikanischen Botaniker William Russel Dudley (1849–1911).[1]
Die Arten der Gattung Dudleya sind ausdauernde, kahle Rosettenpflanzen mit meist faserigen Wurzeln und sukkulenten Blättern. Ihre Triebe sind nicht verzweigt oder verzweigt, dann meist dichotom. Sie sind an ihrer Basis meist mit mehr oder weniger vertrockneten Blättern oder Blattbasen bedeckt. Die Triebe sind meist kurz und etwas aufrecht und erreichen Durchmesser zwischen 10 und 40 Millimeter (selten 1,5 bis 90 Millimeter). Die Rosetten stehen endständig an den Trieben. Sie besitzen Durchmesser von 3 bis 25 Zentimetern (selten 1 bis 50 Zentimeter) und bestehen aus 20 bis 40, selten 3 bis 120 Blättern. Die Blätter sind in ihrer Form sehr variabel. Meist sind sie mehr oder weniger länglich bis länglich (verkehrt-)lanzettlich. Die Blattoberseite ist meistens mehr oder weniger flach oder leicht konkav bis rinnig. Ihre Unterseite ist meist etwas gerundet bis konkav. Sie sind mit einer breite Basis vollständig mit der Sprossachse verbunden und an der Basis oft verbreitert. Die Blattspitze ist stumpf-abgerundet bis scharf-spitz. Die glauken bis dicht bemehlten Blätter sind meist immergrün. Sie werden 1 bis 10 Zentimeter (selten 0,6 bis 40 Zentimeter) lang, 0,2 bis 3 Zentimeter (selten bis zu 10 Zentimeter) breit und sind 2 bis 6 Millimeter (selten 1 bis maximal 25 Millimeter) dick.
Die einzelnen bis zahlreichen, meist mehr oder weniger aufrechten bis aufsteigenden Blütentriebe erscheinen jährlich aus den Blattachseln. Sie sind 5 bis 40 Zentimeter (bis maximal 100 Zentimeter) lang. Der zymöse Blütenstand besteht aus 3 bis 20 (selten 2 bis 30) Blüten. Die fünfzähligen (selten vierzähligen) duftlosen Blüten sind obdiplostemon. Der Blütenkelch ist 3 bis 8 Millimeter (selten 2 bis 9 Millimeter) lang. Seine Kelchblätter sind an der Basis miteinander verwachsen. Ihre freien Kelchzipfel sind 1,5 bis 6 Millimeter (selten 1 bis 8 Millimeter) lang. Die Blütenkrone hat Durchmesser von 3,5 bis 23 Millimeter und eine Länge von 1 bis 4 Millimetern (selten 0,5 bis 10 Millimetern). Ihre meist blass gelblichen bis gelben Kronblätter sind meist etwas elliptisch bis länglich oder eiförmig. Die Kronzipfel sind mehr oder weniger aufrecht oder von der Mitte bis zur Spitze etwas spreizend-ausgebreitet bis zurückgebogen.
Die zehn Staubblätter stehen in zwei Kreisen. Sie sind kürzer als Kronblätter. Die Staubbeutel sind meist gelb und 1 bis 2 Millimeter lang. Die gestutzten Nektarschüppchen sind 0,5 bis 2 Millimeter breit. Der Griffel ist schlank.
Die Frucht ist eine mehr oder weniger braune oder bräunliche und nur selten rote Balgfrucht. Die darin enthaltenen mehr oder weniger braunen, schmal spindelförmigen Samen sind 0,5 bis 1,5 Millimeter groß. Ihre Samenschale ist gerippt.
Die Gattung Dudleya ist im Südwesten Oregons, im Süden Nevadas, in Zentral- und West-Arizona und in Kalifornien in den Vereinigten Staaten sowie in den mexikanischen Bundesstaaten Sonora und Baja California verbreitet, wo die Pflanzen in meist küstennahen Gebieten vorwiegend an felsigen Stellen wachsen.
Die Erstbeschreibung durch Nathaniel Lord Britton und Joseph Nelson Rose wurde 1903 veröffentlicht.[2] Nach Joachim Thiede wird die Gattung Dudleya in drei Untergattungen mit folgenden Arten untergliedert:[3]
Zur Gattung gehören außerdem noch die Hybriden Dudleya × semiteres (Rose) Moran und Dudleya × sproulii P.H. Thomson.
Dudleya ist eine Pflanzengattung aus der Familie der Dickblattgewächse (Crassulaceae). Der botanische Name der Gattung ehrt den US-amerikanischen Botaniker William Russel Dudley (1849–1911).
Dudleya, commonly known as liveforevers (Spanish: siemprevivas) is a genus of rosette-forming succulent plants in the stonecrop family, Crassulaceae, consisting of about 68 taxa in southwestern North America and Guadalupe Island. The species come in many forms, with some large and evergreen, others geophytic and deciduous. Yet, despite their dramatic variations in appearance, most species readily hybridize. The flowers of Dudleya have parts numbered in fives, with the petals arranged in tubular, star-shaped, and bell-shaped forms and, when fruiting, are filled with tiny, ovoid-crescent-shaped seeds.
The genus evolved as neoendemics, from ancestors in the stonecrop genus, Sedum. The ancestors radiated southward from Sedum during the creation of the dry summer climate, in the California region, five million years ago. Early botanists classified the larger species as Echeveria and Cotyledon, while the geophytic species were placed under Sedum. Taxonomic efforts, started by Joseph Nelson Rose and Nathaniel Lord Britton, created three genera; these initial genera were all eventually subsumed into Dudleya, proper, following Reid Moran's investigations into the genus. Phylogenetic research is still at an early stage in the genus, and is complicated by the fact that many species are becoming endangered and over-harvested (poached).
Dudleya is a relatively obscure genus, in comparison to other, more widely-cultivated succulents; converging interests, by succulent collectors, native plant enthusiasts and gardeners alike, have led to the wider cultivation of many species as ornamental plants. In the wild, many species of Dudleya are vulnerable, as land development and poachers often threaten particularly niche populations of plants. Poached plants are often shipped to East Asia, especially South Korea, where hybridisation and cultivation of succulents is very popular. Conservationists, nurseries and governments combat Dudleya poaching through propagation programs and protection laws.
This genus is the only taxon of the Sedeae tribe to have evolved sympodial branching.[2]
The genus is traditionally divided into three subgenera, two of which were formerly their own genera. The subgenera consist of Dudleya, Stylophyllum, and Hasseanthus.[3][4]
One of the most famous features of some Dudleya are their waxy coating. Numerous species have their foliage covered in an epicuticular wax, or farina.[5] This waxy coating is usually white, chalky, and mealy, and is the namesake in many epithets, like chalk dudleya, powdery liveforever, and giant chalk dudleya. The wax on the giant chalk dudleya is a surface with some of the highest ultraviolet reflectivity ever discovered in plants. When exposed to water, the wax may coat drops on leaves, preventing their evaporation.[10] The farina is mostly composed of pentacyclic triterpenoids.[11]
Other members, such as D. viscida and D. anomala, have a clear, sticky layer on their foliage.[12] This adhesive layer ultimately helps the plant protect its leaves from the sun, much like ones with "white" wax. It accomplishes this solar protection by allowing dust to adhere to the sticky layer on the leaves, which coats the foliage with dust and debris, blocking solar radiation.[13]
The earliest species of the genus described was Cotyledon caespitosa, by Adrian Hardy Haworth in 1803, which would later be known as Dudleya caespitosa. The same species would later be described again as Sedum cotyledon by Joseph Franz von Jacquin in 1811, and in 1840 Thomas Nuttall described both Echeveria pulverulenta (Dudleya pulverulenta) and Echeveria lanceolata (Dudleya lanceolata). The differing generic placements of these early descriptions suggest that taxonomic disagreements over the genus had an early start, with some of these generic placements persisting even after the proper description of the genus by Britton and Rose.[3]
Nathaniel Lord Britton and Joseph Nelson Rose's revision of the North American Crassulaceae upended many of the early taxonomic classifications, with the newly-minted genus Dudleya containing 60 species, of which 41 were newly described by Britton and Rose. The two also defined the related genera Stylophyllum, which contained 12 species, and Hasseanthus, with 4 species. The primary differences between Dudleya and Stylophyllum were between the leaf shape, floral structure and petal orientation, whilst Hasseanthus was characterized by a different vegetative structure and more niche adaptations, primarily corm-like stems and deciduous leaves.[4]
In the 1930s, Alwin Berger revised the status of Dudleya and Stylophyllum into a sectional ranking within Echeveria, while merging the Hasseanthus genera into Sedum. This was in part due to a belief that Dudleya had evolved from Echeveria radiating northward from Mexico, evidenced by the similar tubular corollas, while Hasseanthus possessed aesthetic similarities to Sedum, primarily flowers with broadly-spreading petals. Stylophyllum was believed to occupy a transitory position between Dudleya and Hasseanthus. These conclusions were widely accepted by botanists for the first half of the 20th century, until proper molecular and phylogenetic analyses began to appear.[4]
In 1942, Reid Moran, a botanist with a longstanding interest in the genera, offered a new revision of the taxa. Moran recognized Dudleya as being distinct from Echeveria, and merged Stylophyllum as a subgenera along with Eududleya (which was changed to just subgenus Dudleya). Moran still recognized Hasseanthus as a separate genus, but realized that it was closely related to Dudleya. With assistance from cytologist Charles H. Uhl, Moran came to the conclusion that Dudleya and Hasseanthus were related closer to each other than they were to Echeveria or Sedum.[4]
As Moran and Uhl conducted more cytological and taxonomic research on the genus, it became clear that Hasseanthus was also a subgenera of Dudleya, citing the karyological uniformity and the formation of hybrids between the genera.[4] In contrast, while Echeveria and Sedum freely hybridize within themselves and each other, all attempts at hybridizing Dudleya with Echeveria have failed. Uhl came to the conclusion that there are probably no intergeneric hybrids with Dudleya, believing that Dudleya had split from Echeveria far enough that intergeneric reproductive success was unlikely. Despite Uhl's research, he still believed that Dudleya had evolved northward from Mexico with Echeveria, probably some time before the formation of the summer-dry climate of California, making Dudleya a paleoendemic.[14]
Around 1993, one of the only literary treatments of the genus was written, Paul H. Thomson's Dudleya and Hasseanthus Handbook.[6] In the book, Thompson made numerous changes and adjustments to species, and described several new species. The book included a large number of photographs, extensive descriptions, and horticultural practices for the care of Dudleya, derived from a long interest growing, visiting and collecting the plants. However, he failed to follow the International Code of Botanical Nomenclature guidelines for describing new taxa, forgoing designated type specimens, which invalidated his treatment.[15] His treatment also contains extensive pseudoscientific material, including references to the lost continents of Atlantis, Lemuria and Mu, a belief that cosmic rays and divine intervention directly induced the chromosome counts and evolution of Hasseanthus and Dudleya, and criticism of paleontologists and the scientifically accepted age of the Earth.[6]
Later research challenged the notion that Dudleya and Echeveria formed two distinct lineages within Echeverioideae. Joachim Thiede instead proposed that Dudleya evolved completely independently from Echeveria, evolving from relatives within the Leucosedum clade like Sedum moranii. This places Dudleya as a neoendemic that evolved recently with the formation of the summer-dry climate in California. This was evidenced by the similarities of seed-surface ornamentation between Dudleya and Sedum, which is unlike Echeveria, and the reproductive isolation between Echeveria and Dudleya.[3][16][17]
Research in the 21st century has supported the hypothesis of Dudleya's relation to Sedum. Phylogenetic analysis has given weight to this hypothesis, concluding that Dudleya is much closer to North American members of Sedoideae than to Echeverioideae. The plant Sedum spathulifolium, which co-exists with Dudleya in Oregon and California, has been show in multiple phylogenetic reconstructions to be a sister taxon to Dudleya, although it may not be the true sister taxon, as larger samplings are needed. Berger's hypothesis of a relationship between Hasseanthus and Sedum may still prove true, as in addition to morphological similarities, the Hasseanthus-type taxa could be basal to the genus. However, no truly conclusive evidence of significant divergence within Dudleya exists, and it remains unclear which groups are basal or derived.[18]
The genus is named after William Russel Dudley, the first head of the botany department at Stanford University.[5] The term liveforever may refer to the longevity and hardiness of some plants in the wild.[21]
The name of the subgenera Stylophyllum is an allusion to the pencil-shaped leaves of the type species,[22] Stylophyllum edule, now known as Dudleya edulis.[6]
The name of the subgenera Hasseanthus was in honor of Dr. Hermann E. Hasse, a surgeon and collector of California flora. Dudleya virens subsp. hassei is also named after him.[6]
The pollinators of Dudleya are mostly hummingbirds and bees, although this has been inferred in some species only from flower morphology. The genus exhibits a wide array of diverse flower varieties, even within species complexes. The flowers are mostly hermaphroditic, although some individuals may have sterile anthers. Plants with long, tubular, reddish flowers, mostly in the subgenus Dudleya, are adapted towards pollination via hummingbirds, while short, spreading, yellow flowers favor pollination by insects. Despite the evolution of long flowers towards hummingbirds, the long flowers also show no performance disadvantage in pollination environments exclusively composed of insects. While the long flowers may provide an evolutionary advantage for more effective pollination, more energy is required to produce the larger amounts of floral tissue.[24]
The flower morphology of Dudleya also corresponds with the aforementioned groups of Hasseanthus, Stylophyllum, and Dudleya. The flowers in Hasseanthus and Stylophyllum are broad, white to yellow, and spreading, with bumblebees and bees as primary pollinators, and hummingbirds as occasional pollinators. As these species grade towards the subgenus Dudleya, the petals begin to fuse at the base, with the flowers becoming tubular and red, due to an association with hummingbird pollinators. This shift in pollinators corresponds to larger nectar volumes and higher energy contents in accordance with the demands of hummingbird pollinators.[3]
Seed morphology also differs between Dudleya. Larger Dudleya have noticeably smaller seeds; this is likely a result of an evolutionary tradeoff. The investment in growing large allows plants to retain moisture in periods of drought, at the cost of energy placed into reproduction. Other reasons for smaller seeds may also be due to allocation of resources into vegetative reproduction via pup rosettes, instead of sexual reproduction. In contrast, the small, inconspicuous, Hasseanthus-type members produce the largest seeds in the genus. These larger seeds are not distributed very far, which contributes to the restricted ranges of the Hasseanthus subgenus.[7]
subg. Dudleya — The flowers of Dudleya caespitosa
.jpg)
subg. Dudleya — The flowers of Dudleya anthonyi
subg. Stylophyllum — The flowers of Dudleya edulis
subg. Stylophyllum — The flowers of Dudleya virens subsp. hassei
subg. Hasseanthus — The flowers of Dudleya blochmaniae
subg. Hasseanthus - The flowers of Dudleya variegata
Dudleya species are widespread and diverse in their range, but are typically found in rock outcroppings, cliff faces, or road cuts, where their leaves help them store water in a setting too dry for most types of plants. Most are small and inconspicuous when not in bloom.[5] The two predominant habitats where plants of this genera may be found are by the coast or mountains. Dudleya favor moderate temperatures, summer dormancy, winter precipitation, and rocky habitats, which means they may be found in diverse, disjunct locales from oceanic bluffs on the California coast to sky islands in Arizona.[3]
Regions where Dudleya can be found include The Californias, Arizona, coastal Sonora and Oregon, and southern Utah and Nevada.[3] The diversity of species of Dudleya is centered in Southern California and northern Baja California.[16]
In horticulture, Dudleya should be planted at an angle.[25] This allows accumulated water to drain from the nestlike center of the plant, thus preventing microbial decay.[26] Dudleya should not be watered from directly above, as this may damage their chalky coating known as farina, which is present on numerous species.[6][25]
During the late fall to early spring period of growing, watering should be done frequently in order to promote good growth and flower development. Plants grown with exposure to rainfall, provided they are in a Mediterranean climate, they may obtain optimum moisture. In contrast, plants grown indoors or in greenhouses should be watered to ensure that the plant maximizes growth.[6]
During the dormant period, from late spring to fall, watering should be limited to bi-weekly intervals, but not completely cut out. In nature, plants may completely desiccate themselves during the dormant period.[25] Deciduous members of the genus in the Hasseanthus grouping should not be watered at all during dormancy.[6]
Growing mediums should attempt to imitate the preferred soil of each species in nature. The most essential element for the medium is good drainage.[25] Good drainage is important, as Dudleya are very susceptible to mold and fungi. How quickly the medium drains should be determined by the amount of shade in the location, which affects the rate of evaporation that the soil will go through. Thus, well-shaded Dudleya must have excellent drainage.[6]
Fertilizers may be used to maintain good color and growth, but they should be diluted.[6][27]
Clay is preferable to plastic pots when growing the plants due to the advantages with water drainage. Plastic pots may also kill the plants by overheating the roots.[6]
Mealybugs and aphids are main pests of Dudleya.[28][29] Powdery mildew has also been recorded in cultivated Dudleya.[30]
The amount of shade a species of Dudleya requires is dependent on the location. Plants growing in coastal regions may require little shade at all, whilst plants growing in the deserts, inland valleys and mountains will require shade. The majority of plants in the genus will appreciate north-facing sites and shade during the heat of the day. During the summer months, 50% shade may be beneficial for plants. If a cold-tolerant Dudleya is grown during a freeze or snow, it should be shaded as not to damage the plant, as a quick thaw may be detrimental.[6]
Unlike their related genera Echeveria, many Dudleya cannot be propagated through leaf cuttings. Propagation is mostly achieved via offsets, germination by seed, or in nurseries, plant tissue culture.[6]
Dudleya seeds are crescent shaped and near-microscopic, and can be collected by taking the dried flower buds and crushing the ovules inside, which can contain hundreds of seeds. Seeds can be sown into a soilless medium, such as pumice or vermiculite, after which germination can occur within a week to 10 days.[31]
Vegetative reproduction may occur in multiple ways:[6]
The indigenous peoples of the Kumeyaay and Paipai region utilized the genus for both medicinal and agricultural purposes. The tender, succulent leaves were chewed on to alleviate thirst, or used to treat calluses and corns. The budding inflorescences, in their early stages, were used as food, with a sweet flavor and juicy texture. The roots were pounded up and soaked in water, used as an astringent to "tighten the gums." The roots were also boiled whole as a decoction for asthma.[23][34]
Several species of Dudleya are threatened by urban development in Coastal California and Mexico, and anthropogenic-induced wildfires. However, one of the most critical threats to Dudleya species is poaching, partially caused by a demand from East Asian succulent collectors paying lucrative prices for certain Dudleya species.[35]
The population of Verity's liveforever (Dudleya verityi), which was nearly wiped out during the 2013 Springs Fire, was targeted by poachers.[36][37]
The Cedros Island liveforever (Dudleya pachyphytum) is a rare and extremely specialized Dudleya endemic to Cedros Island. In 2016, Korean nationals began moving to Bahia Tortugas, a locality in Baja California Sur, to facilitate the poaching and shipping of the plants.[38] The species was seriously threatened after Mexican soldiers discovered poachers taking nearly 5,000 rosettes in a tractor-trailer.[39] It was suspected the poachers rappelled onto the succulent's location via helicopter, as D. pachyphytum occupies a nearly inaccessible habitat.[40] In 2019, the deaths and injuries of several fishermen from Bahía Tortugas who were on Cedros Island was allegedly the result of Dudleya trafficking, a conflict with the Sinaloa Cartel, or both.[41] In 2020, the Mexican Navy in the Second Naval Region revealed that two fishermen were killed after a dispute emerged over the trafficking of the rare plant.[42][43]
Bluff lettuce (Dudleya farinosa) was also targeted by poachers in numerous large-scale operations. Although not particularly rare, the size of the poaching operation pose a serious ecological threat. Starting in 2017, the U.S. Customs and Border Protection, along with the California Department of Fish and Wildlife, discovered large amounts of D. farinosa being shipped out of the country. South Korean and Chinese nationals have both been arrested in the smuggling of D. farinosa. According to nursery owners responsible for legally exporting Dudleya, buyers in Asia desired plants directly from the wild, owing to the aesthetic quality of their long caudices and weathered leaves.[44][45]
The candleholder dudleya (Dudleya candelabrum), native to the northern Channel Islands, was reported to have been poached, with the thieves shipping plants to South Korea.[46][47]
In response to the poaching of Dudleya, California State Assembly member Chris Ward proposed Bill AB-223, sponsored by the California Native Plant Society, which would make it illegal to poach Dudleya from state or private lands without a permit.[48] The California Native Plant Society and conservationists have also initiated propagation programs to oversaturate the market as a means to deter poachers.[31][33] On September 28, 2021, governor Gavin Newsom signed AB-223 into law.[49]
Dudleya, commonly known as liveforevers (Spanish: siemprevivas) is a genus of rosette-forming succulent plants in the stonecrop family, Crassulaceae, consisting of about 68 taxa in southwestern North America and Guadalupe Island. The species come in many forms, with some large and evergreen, others geophytic and deciduous. Yet, despite their dramatic variations in appearance, most species readily hybridize. The flowers of Dudleya have parts numbered in fives, with the petals arranged in tubular, star-shaped, and bell-shaped forms and, when fruiting, are filled with tiny, ovoid-crescent-shaped seeds.
The genus evolved as neoendemics, from ancestors in the stonecrop genus, Sedum. The ancestors radiated southward from Sedum during the creation of the dry summer climate, in the California region, five million years ago. Early botanists classified the larger species as Echeveria and Cotyledon, while the geophytic species were placed under Sedum. Taxonomic efforts, started by Joseph Nelson Rose and Nathaniel Lord Britton, created three genera; these initial genera were all eventually subsumed into Dudleya, proper, following Reid Moran's investigations into the genus. Phylogenetic research is still at an early stage in the genus, and is complicated by the fact that many species are becoming endangered and over-harvested (poached).
Dudleya is a relatively obscure genus, in comparison to other, more widely-cultivated succulents; converging interests, by succulent collectors, native plant enthusiasts and gardeners alike, have led to the wider cultivation of many species as ornamental plants. In the wild, many species of Dudleya are vulnerable, as land development and poachers often threaten particularly niche populations of plants. Poached plants are often shipped to East Asia, especially South Korea, where hybridisation and cultivation of succulents is very popular. Conservationists, nurseries and governments combat Dudleya poaching through propagation programs and protection laws.
Dudleya es un género de plantas suculentas perteneciente a la familia Crassulaceae y que tiene unas 45 especies aceptadas.[1] Son nativas del sudoeste de Norteamérica.
Son plantas herbáceas con hojas carnosas y glaucas que se desarrollan en una roseta basal, los colores varían del verde al gris. Las inflorescencias se encuentran en tallos verticales o inclinados a un metro de altura sobre la cima con brácteas como hojas alternas. Tiene pequeñas flores con cinco sépalos y cinco tépalos fusionados debajo, cinco pistilos, también fusionados y 10 estambres en su alrededor.
Las especies de Dudleya se encuentran ampliamente distribuidas en roquedales, acantilados, bordes de carreteras, donde sus hojas ayudan a almacenar el agua en lugares demasiados secos para otras plantas.
El género fue descrito por Britton & Rose y publicado en New or Noteworthy North American Crassulaceae 12–28. 1903.[2][3]
Es género fue nombrado en honor de William Russell Dudley, el primer director del departamento de botánica de la Universidad de Stanford.
Dudleya es un género de plantas suculentas perteneciente a la familia Crassulaceae y que tiene unas 45 especies aceptadas. Son nativas del sudoeste de Norteamérica.
Hopearuusukkeet (Dudleya) on maksaruohokasveihin kuuluva mehikasvisuku, jossa on 40 lajia. Niitä esiintyy Yhdysvaltojen etelä- ja lounaisosissa seka Meksikon pohjois- ja luoteisosissa. Hopearuusukkeet ovat tyvestä lehtiruusukkeellisia monivuotisia sukkulenttikasveja. Niiden kukat ovat putkimaisia, kellon- tai tähdenmuotoisia, keltaisia, valkoisia tai punaisia.[1] Joitain hopearuusukelajeja viljellään huonekasvina.[2]
Santabarbaranhopearuusuke.
Hopearuusukkeet (Dudleya) on maksaruohokasveihin kuuluva mehikasvisuku, jossa on 40 lajia. Niitä esiintyy Yhdysvaltojen etelä- ja lounaisosissa seka Meksikon pohjois- ja luoteisosissa. Hopearuusukkeet ovat tyvestä lehtiruusukkeellisia monivuotisia sukkulenttikasveja. Niiden kukat ovat putkimaisia, kellon- tai tähdenmuotoisia, keltaisia, valkoisia tai punaisia. Joitain hopearuusukelajeja viljellään huonekasvina.
Dudleya je rod od oko 40 vrsta koje dolaze iz jugozapada SAD-a i Meksika. Neko vrijeme bile su smještene u rod Cotyledon, pa nakon toga u rod Echeveria dok na kraju nisu dobile svoj vlastiti rod. Ovaj rod je dobio ime po profesoru Williamu Dudleyu.
Dudleya su sukulentne rozete. Starije biljke se mogu rezati radi presađivanja. Nakon što smo odrezali dio biljke, taj dio treba ostaviti 3 dana na suhom da vidimo je li biljka zdrava, a nakon toga biljku treba presaditi u novu zemlju. Najbolje vrijeme za rezanje biljaka je kasno proljeće i ljeto. Ove biljke zahtijevaju puno sunca.
Ove vrste rastu zimi i ne podnose jako zalijevanje tokom ljetnih dana. Cvjetaju u proljeće.
Većina vrsta može podnijeti smrzavanje.
Vrste:
Dudleya is een geslacht van succulenten uit de vetplantenfamilie (Crassulaceae). De soorten komen voor in het zuidwesten van Noord-Amerika.
Dudleya abramsii
Dudleya anomala
Dudleya anthonyi
Dudleya arizonica
Dudleya blochmaniae
Dudleya brittonii
Dudleya caespitosa
Dudleya candelabrum
Dudleya cymosa
Dudleya edulis
Dudleya farinosa
Dudleya gnoma
Dudleya hassei
Dudleya nesiotica
Dudleya palmeri
Dudleya pulverulenta'
Dudleya saxosa
Dudleya traskiae
Dudleya verityi
Dudleya viscida
Dudleya is een geslacht van succulenten uit de vetplantenfamilie (Crassulaceae). De soorten komen voor in het zuidwesten van Noord-Amerika.
Multimedia w Wikimedia Commons Dudleya – rodzaj sukulentów występujących w płd.-zach. części Ameryki Północnej, obejmujący około 45 gatunków.
Rodzaj Dudleya należy do podrodziny Sempervivoideae, rodziny gruboszowatych (Crassualaceae), do rzędu skalnicowców (Saxifragales) i wraz z nim do okrytonasiennych.
Gromada okrytonasienne (Magnoliophyta Cronquist), podgromada Magnoliophytina Frohne & U. Jensen ex Reveal, klasa Rosopsida Batsch, podklasa różowe (Rosidae Takht.), nadrząd Saxifraganae Reveala, rząd skalnicowce (Saxifragales Dumort.), rodzina gruboszowate (Crassulaceae DC. in Lam. & DC.), rodzaj Dudleya[2].
Dudleya – rodzaj sukulentów występujących w płd.-zach. części Ameryki Północnej, obejmujący około 45 gatunków.
Dudleya é um género botânico pertencente à família Crassulaceae[1].
Dudleya é um género botânico pertencente à família Crassulaceae.
«Dudleya — World Flora Online». www.worldfloraonline.org. Consultado em 19 de agosto de 2020Рід отримав назву від імені професора Стенфордського університету Вільяма Дадлі.
Багаторічні сукулентні рослини з укороченим стеблом. Деякі види утворюють невеликий каудекс. Більшість видів — розеткові рослини, але деякі — чагарнички до 40 см заввишки. Стебла — одиночні або вилкоподібно розгалужені, низькі, часто дуже вкорочені. Листки — м'ясисті, соковиті, переважно ланцетні, видовжено-ланцетні, лінійні, дуже різноманітні за формою, сизі або зелені, нерідко мають вапняно-білий наліт. На верхівках пагонів листя по 50-100 штук зібрані в розетку діаметром від 2 до 50 см. Квітки — 5-членні, дзвоникоподібні, 0,7 — 1,5 см завдовжки, зібрані у верхівкові метельчаті або щитковидні суцвіття, мають жовтавий, червоний, рожевий або білий колір. Квітконоси із сильно редукованим листям виходять з пазух листків.
Дудлеї знаходяться у близькому рідстві з Ечеверіями і зовнішньо дуже схожі. В природі вони нерідко зростають поруч, однак дудлеї ростуть повільніше.
Гібриди серед мексиканських товстолистих дуже рідкісні в дикій природі, ймовірно, тому що ті деякі види, які зустрічаються разом і цвітуть, в той же час обслуговуються різними запильниками. Тим не менше, більшість видів і родів легко схрещуються у вирощуванні. Якобсен і Роулі у 1958 запропонували спеціальну назву для міжродових гібридів Dudleya з Echeveria — х Dudleveria.
Рослини цього роду поширені на південному заході США і півночі Мексиці.
Види Dudleya traskiae і Dudleya stolonifera знаходяться на грані зникнення і їх продаж заборонений без спеціального дозволу.
В культурі вирощують переважно розеточні дудлеї. В колекціях зустрічаються багато видів. Рослини утримують в світлих приміщеннях, на яскравому сонці злегка притінюють. З весни до осені регулярно поливають по мірі висихання ґрунту. Взимку утримують сухо при температурі 5 — 10 °C. Землесуміш — повітро і вологопроникна, складається з рівних частин лтистової землі і піску.
Розмножують переважно насінням, або підсушеними протягом декількох днів листовими живцями.
Колекція Ботанічного саду імені академіка Олександра Фоміна в Києві представлена вісьмома видами.
За різними джерелами рід Дудлея налічує від 40 до 50 видів:
Dudleya là một chi thực vật có hoa trong họ Crassulaceae.[1]
Bài viết chủ đề họ Lá bỏng này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Dudleya là một chi thực vật có hoa trong họ Crassulaceae.
_(13998561076).jpg)
.jpg)
.jpg)
.jpg)
