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Stephan L. Hatch 《西北部美国博物学家》2011,36(2)
An investigation was made of Elymus simplex to evaluate the current taxonomy and cytology. The study included herbarium specimens from Wyoming and Colorado and population samples from the type location in Wyoming. The most important taxonomic characters noted are: numbers of spikelets per node, lemma awn length, and habitat. The chromosome number of E. simplex is reported as 2 n =28. E. simplex is a distinct species and should not be confused with E. salina, from which it differs morphologically. 相似文献
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Cited are distribution records for Alaska of Cicuta bulbifera L. It was discovered growing in the Nowitna National Wildlife Refuge in north central Alaska in 1984 and again in 1987. An earlier record is also known from near Fairbanks. 相似文献
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Cliffrose ( Cowania mexicana var. stansburiana [Torr.] Jepson) community measurements were taken in central Utah. Data revealed a high between-site similarity of 78.5%. Soil analysis for sites showed most macronutrients, and some micronutrients, relatively low. Cover of cliffrose was found to increase with increases in soil magnesium (p ≤ 0.01). Plants growing on the sites have adapted life cycles to exploit moisture and nutrients during seasons of maximum availability. Prevalent species in the community were cheatgrass ( Bromus tectorum ), cliffrose, madwort ( Alyssum alyssoides ), and bluebunch wheatgrass ( Agropyron spicatum ). Annual grasses were the most important life form to community composition; the second was shrubs. Ratios between soil nutrients and cliffrose tissue nutrients indicate active transport of some elements. Data indicated a steady decline in establishment of new cliffrose individuals on the sites since 1957. This lack of reproductive success is most likely due to a combination of factors but appears most influenced by the elevated levels of annual plants (mainly cheatgrass) on the sites. If the cliffrose communities in central Utah are to be maintained, special attention to their management must be considered and implemented. 相似文献
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Egg deposition by the soil mites Trichouropoda (= Oodinychus) ovalis (C.L. Koch and Uroobovella (= Fuscuropoda) marginata (C.L. Koch), egg incubation and hatching behaviour were observed using continuous video-monitoring. The oviposition in both species was found to consist of three distinct phases. In Phase 1, both species engage in pre-ovipositional activity prior to the egg being extruded from the genital opening. Phase 1 lasted approximately 7.5 minutes in T. ovalis and about 6 minutes in U. marginata. Phase 2 involved egg deposition and lasted approximately 2.5 times longer in T. ovalis (88 seconds) than in U. marginata. Egg covering occurs in Phase 3, and in both species lasts about 25 minutes. Incubation time in U. marginata (137 hours) was approximately 30% shorter compared to that of T. ovalis, while the hatching time was 2 times longer (150 min) in the latter species. 相似文献
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《Journal of Natural History》2012,46(6):855-859
The zygopteran Calopteryx virgo from a habitat in western Norway was found to be infected by the eugregarine Hoplorhynchus oligacanthus. Females were most heavily infected, in contrast to other gregarine-infected zygopteran species, where no differences between males and females have been recognized. This disparity between males and females of C. virgo is attributed to their dissimilar behaviour and place of activity. The gregarine infection of C. virgo is considered in relation to infected coexisting zygopteran populations. 相似文献
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《Journal of Natural History》2012,46(12):1385-1396
Epibiontic mollusc communities associated with Pinna nobilis L. in the Straits of Messina (Sicily, Italy) are described. Some relationships were found between species richness and diversity in respect to shell size. Progressive variations in community structure were found, demonstrating how epibiontic communities evolve towards a well-characterized biocoenosis. On the contrary, environmental and anthropogenic disturbances hinder this process, favouring an increase in species richness and Shannon-Wiener diversity. 相似文献
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Stanley L. Welsh 《西北部美国博物学家》2011,55(1)
The names and types of Hedysarum L., sensu stricto, for North America are included, along with bibliographic citations, type information and place of deposit of types, and all synonyms. Lectotypes are designated for Hedysarum auriculatum Eastw., H. carnulosum Greene, H. marginatum Greene, H. pabulare A. Nels., and H. truncatum Eastw. 相似文献
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《Journal of Natural History》2012,46(47-48):2851-2872
In this study, the first molecular phylogenetic analysis of Mesobuthus eupeus in Iran is presented based on sequence data of a ~ 700-base-pair fragment of cytochrome C oxidase, subunit I. Phylogenetic relationships were inferred using parsimony, maximum likelihood and Bayesian inference. The results support monophyly of M. eupeus, but there is a clear divergence between northern and southern clades. The northern clade includes four subspecies – M. e. eupeus, M. e. philippovitschi, M. e. afghanus and M. e. thersites; whereas the southern clade is comprised of two others – M. e. phillipsi and M. e. kirmanensis. Accordingly, possible scenarios for the evolution and phylogeographic structure of M. eupeus based on the geological history of the Iranian Plateau were proposed. The observation of two distinct lineages supports the proposal that M. eupeus might be a species complex composed of species with highly similar morphological features. 相似文献
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《Journal of Natural History》2012,46(1):33-40
A second species of Josephiella Narendran, J. microcarpae, is described and figured, based on specimens reared in Hawaii, California and the Canary Islands. This wasp develops in galls on the leaves of Ficus microcarpa L., a widely cultivated ornamental banyan tree that is native to South-East Asia and adjacent islands. It has not been found on any other hosts. Both sexes are described, and males, which are apparently all fully winged, are relatively rare. We postulate that this wasp is a recent introduction into Hawaii, California and the Canary Islands, from an unknown location in South-East Asia, where Ficus microcarpa is native. 相似文献
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We studied the breeding system and flower visitors of White River penstemon, a rare endemic from the Uintah Basin of eastern Utah and western Colorado. Bagging treatments and hand-pollination treatments showed that Penstemon scariosus var. albifluvis has a mixed mating system: while some seeds and fruits are produced through selfpollination (both autogamy and geitonogamy), significantly more are produced when flowers are cross-pollinated. The primary flower visitors, and likely pollinators, were several species of native twig- and ground-nesting bees in the families Apidae, Halictidae, and Megachilidae. We found no differences in fruit or seed production between open-pollinated controls and hand-outcrossed flowers, suggesting that pollinator visits were sufficient to maximize female reproductive success. Management plans to conserve White River penstemon must recognize that full reproductive success of this rare plant taxon relies on a suite of pollinating bees, and that the species richness and abundances of bee visitors should be maintained. 相似文献
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《Journal of Natural History》2012,46(12):1833-1848
The Australian species of Chromotydaeus Berlese and Penthaleus C. L. Koch (Acarina: Penthaleidae) are revised. Chromotydaeus quartus n. sp. and Penthaleus falcatus n. sp. are described, and P. major (Dugés) and P. minor (Canestrini) redescribed. P. major is an agricultural pest, but all the other species appear to have no economic importance. 相似文献
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《Journal of Natural History》2012,46(3):409-422
Summary Some variations in the percentage infection of the cockle, Cardium edule L., on Llanrhidian sands, South Wales with Cercaria bucephalopsis haimeana (Lacaze-Duthiers, 1854) are described. Vertical variations in percentage infection are related to the population density of the final hosts and the seasonal variation with the breeding cycle of the first intermediate host. Only spent adult cockles, over 18·0 mm long and one year old, are infected, the highest percentage infection occurring in three-year old cockles. A decline in the percentage infection in older cockles suggests an increase in the mortality of infected specimens together with an increase in resistance to infection with age. Medium-sized cockles have a higher percentage infection than smaller and larger cockles of the same age. The parasite causes a decrease in the host's shell growth rate but an improvement in the flesh yield. The possible reasons for the variations in percentage infection and the effect of the parasite on the host are discussed. 相似文献
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