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Described as a new species is Oreoxis trotteri Welsh & Goodrich from Utah.   相似文献   

3.
A comparison of the floral visitors of two closely related plant species, Penstemon cyananthus and P. eatonii suggests that flower shape and color may affect the number and type of pollinators, and the ability of the plant to set fruit. Penstemon cyananthus, which is most attractive to hymenopteran visitors, has a blue flower, large in diameter, that is positioned as a convenient “landing pad.” Although many types of insects visit the flower, the transport of pollen directly to flowers of another individual of the same species is somewhat inefficient, since fruiting success is low (66.7 percent). The tubular red flowers of P. eatonii are narrow and droop downward from the stem. The nectar is accessible to a specific and well-adapted visitor, the hummingbird. This less promiscuous, bird-pollinated species sets fruit more successfully (82.4 percent) than P. cyananthus.  相似文献   

4.
New taxa include Penstemon angustifolius Pursh var. dulcis Neese, P. leonardii Rydb. var. higginsii Neese, P. scariosus Pennel var. cyanomontanus Neese, and P. thompsoniae (Gray) Rydb. var. desperatus Neese. New nomenclatural combinations include: Penstemon acaulis L. O. Williams var. yampaensis (Penl.) Neese, P. duchesnensis (N. Holmgren) Neese, P. leonardii Rydb. var. patricus (N. Holmgren) Neese, and P. pachyphyllus Gray ex Rydb. var. mucronatus (N. Holmgren) Neese.  相似文献   

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Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Described as a new species is Penstemon flowersii Neese & Welsh from Utah. An illustration is provided. The species is named in honor of the late Seville Flowers, professor of botany at the University of Utah.    相似文献   

7.
Named as a new species is Penstemon albifluvis J. L. England. The species is known from the Uinta Basin of Utah and Colorado.  相似文献   

8.
Plant macrofossils from packrat middens in two southeastern Utah caves outline development of modern plant zonation from the late Wisconsin. Allen Canyon Cave (2195 m) and Fishmouth Cave (1585 m) are located along a continuous gradient of outcropping Navajo Sandstone that extends from the Abajo Mountains south to the San Juan River. By holding the site constant, changes in the floral composition for a plot of less than one hectare can be observed, even if sporadically, over tens of millennia. At Allen Canyon Cave, Engelmann spruce-alpine fir forest was replaced by the present vegetation consisting of pinyon-juniper woodland on exposed ridgetops and cliffside stands of Douglas fir, ponderosa pine, and aspen. Xerophytic woodland plants such as pinyon, plains prickly pear, and narrowleaf yucca arrived sometime in the middle Holocene between 7200 and 3400 B.P. At Fishmouth Cave, Utah juniper in Holocene middens replaced blue spruce, limber pine, Douglas fir, and dwarf and Rocky Mountain junipers in late Wisconsin samples. Disharmonious associations for the late Wisconsin occur only at the lower site with the xerophytes Mormon tea, plains prickly pear, and narrowleaf yucca growing alongside subalpine conifers. One possible explanation involves the late Wisconsin absence of ponderosa and pinyon pines from the Colorado Plateaus. Released from competition at their lower limits, subalpine conifers were able to expand into lower elevations and mix with xerophytic plants found today in understories of pinyon-juniper and ponderosa pine woodlands. Quantitative climatic estimates are derived for the late Wisconsin by applying vertical gradients for temperature and precipitation to the amount of vegetation depression. The Fishmouth Cave sequence indicates a minimum lowering of 850 m for blue spruce, limber pine, and dwarf juniper. A depression of at least 700 m for Engelmann spruce and alpine fir is suggested for the Allen Canyon locality. Use of conservatively low gradients for stations below 2080 m yields a 3–4 C cooling from present mean annual temperature and 35 to 60 percent more rainfall than today. Steeper gradients associated with more mountainous terrain suggest a 5 C lowering in temperature and up to 120 percent increase over modern precipitation.     相似文献   

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Presented herein is an index to vascular plant names of Utah. The names are arranged in alphabetical order by genus, species, and infraspecific taxa. Each entry is followed by a bibliographic citation, family name, rarity (whether endemic, rare, or endemic-rare), and origin (whether indigenous, adventive, or adventive-cultivated). Pertinent synonyms are cited beneath appropriate entries. An index of synonyms and a comprehensive bibliography are included.  相似文献   

11.
Presented herein is an index to approximately 800 authors of vascular plant names of Utah. A standardized abbreviation is presented for each author. These are listed alphabetically. Following each abbreviation is the full name and birth and death dates (where available) of each individual. In some cases the date of publication is given when biographical information is not known.  相似文献   

12.
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Seven wetland areas in the subalpine and alpine regions of the Uinta Mountains are described. Most areas have a mosaic vegetation structure, comprised of several patches that are usually sharply demarcated from one another. Each patch has a distinct species composition, usually with only one or two species. Water level is associated with some of the vegetation patterns found in these sites. Standing crop varied from 28 to 360 g/m 2 . Sites show considerable variation in standing crop that could not be explained by elevation differences between sites. Sites with water flowing over them have substantially greater standing crops than sites where water stagnates. Seasonal patterns in shoot density and standing crop indicate one late summer peak in standing crop and little recruitment of shoots over the summer. On stagnant sites, the average stem weight shows a strong relationship to stem density. This pattern did not appear to be caused by thinning mortality and did not follow a “3/2 power law” pattern.    相似文献   

13.
Hanging gardens are insular plant communities of the Colorado Plateau. This study examines hanging gardens in the Narrows, Zion National Park, Utah. The floristic similarity of gardens and the presence of species in classes of variables which characterize the habitat are disclosed. Although the gardens are isolated and dissimilar, the individual species are not restricted in the range of habitat found. Floristic dissimilarity cannot be attributed to differences in habitat. These results are compared to studies of hanging gardens in eastern Utah.    相似文献   

14.
Field and herbarium studies of Penstemon cyananthus Hook. ssp. longiflorus Pennell suggest that this taxon be elevated to species rank.    相似文献   

15.
Six study sites were established in each of three community life form types (grass, forb, and shrub) containing as dominants or subdominants either C 3 and/or C 4 plants. Soil and vegetation samples were analyzed for total nitrogen, phosphorus, magnesium, calcium, potassium, sodium, zinc, iron, copper, and manganese. Discriminant analysis and analysis of variance statistics were used to evaluate differences in mineral content of soils and plant tissues. C 4 plants in all study sites assimilated higher concentrations of potassium, iron, and calcium than did C 3 plants. Forbs in all sites contained the highest concentrations of minerals, followed by shrubs and grasses.  相似文献   

16.
Described as new species are Erigeron cavernensis Welsh & Atwood from the Schell Creek Range and Currant Mountain, White Pine County, Nevada, and Penstemon idahoensis Atwood  相似文献   

17.
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Patterns of zonation along a saline meadow slope were studied. Different species associations were distributed in five zones along the slope which paralleled Utah Lake. The five zones, distinguished on the basis of dominant species and/or life form, were: saltgrass–annual weed, saltgrass-alkaligrass, saltgrass-forb, saltgrass, and spikerush. Soil, vegetation, and plant species data were taken. Patterns of change with respect to these factors were observed along the downslope gradient. Soil pH and soluble salts decreased downslope, while organic matter and moisture increased. Individual ions showed varying patterns. Vegetation and species patterns also varied with slope position. Annuals dominated the ridge tops, while sedge and rush cover were restricted to the slope base. Perennial forb distribution was shown to be correlated with elevated levels of micronutrients in the soil.  相似文献   

18.
Phytoplankton studies during the summer of 1974 in Utah Lake, Utah, demonstrated the development of disjunct distributions of Aphanizomenon flos-aquae and Ceratium hirundinella. Differential response to environmental factors and competitive displacement are proposed as probable explanations for this phenomenon.  相似文献   

19.
A study was made at 18 sites with elevations between 3512 and 3768 m in the Uinta Mountains, Utah. Sites were small in extent but typified vegetation patterns found in the Uintas. Standing crop, species composition (based on dry weight), and values for several physical parameters were determined at each site. Simple linear regressions performed between the various biotic and abiotic characters revealed significant relationships between the characteristics of rocks visible at the surface (the number, size, and variation in size) and vegetation cover. This relationship was probably due to the burial of rocks as a region became vegetated. Bray and Curtis ordinations performed on the data indicated that there were several factors which influenced the species composition but that no single factor dictated the vegetational pattern.  相似文献   

20.
Growing numbers of elk ( Cervus elaphus ) on winter ranges might adversely affect sympatric wintering mule deer ( Odoeoileus hemionus ) if diets of the two species are similar. Diets of elk and deer on a northern Utah range were analyzed for overlap in winter with microhistological analysis of fecal samples. Diets overlapped 71%. No significant difference was found in use of grasses or shrubs between elk and deer; however, use of forbs was significantly different. Shrubs comprised the largest proportion of the diets of both elk and deer. Deer might be under more severe dietary stress than elk on poor winter ranges.  相似文献   

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