共查询到20条相似文献,搜索用时 15 毫秒
1.
Peggy Lee Fiedler 《American journal of botany》1985,72(11):1712-1718
Bulb and leaf tissues from five species in the genus Calochortus and the soils from collection sites were analyzed for cation and trace element concentrations. All five species, only three of which are considered ultramafic endemics, possessed high concentrations of nickel and copper in both the bulbs and leaves, but not at levels high enough (> 1% dry wt) to be considered hyperaccumulators. Only moderate to trace amounts of cobalt and chromium were detected in both plant tissues. Calcium-magnesium ratios, typically low in ultramafic soils and plants, were low in bulb tissue, but two to 10 times higher in leaf tissue. The ability to tolerate excessively high levels of nickel and other heavy metals may be a physiological exaptation of the genus Calochortus and not necessarily an evolutionary response by several species to life on an ultramafic substrate. The nature of “serpentine” endemism is discussed in the context of heavy metal accumulation by various plant species. 相似文献
2.
茜草属为茜草科模式属,全球约80种,中国有近一半的物种,是茜草属的重要分布中心,大部分隶属于sect.Oligoneura。但是,该组内各种间的形态特征错综复杂,依靠单个性状不易划定种间界限。该研究在全面衡量sect.Oligoneura组内各种间形态特征的基础上,选取该组20种共171份标本,对其3个数量性状和28个定性性状进行聚类分析和主成分分析。结果表明:在主成分分析中,前3个主成分累积贡献率有46.88%,性状的累积贡献率增长并不明显,但该结果仍与聚类分析结果一致。对前3个主成分贡献较大的特征包括叶形(叶长宽比)、叶柄长度、叶脉、每轮叶片数和生活型等,这些形态性状也是该属传统分类学中重要的物种鉴定特征。该研究结果与分子系统发育结果基本一致,支持该组内ser.Chinenses、R.mandersii group、R.angustissima group和R.siamensis group类群的划分,但并不支持ser.Cordifoliae单独成系。sect.Oligoneura内除少数物种外,大部分物种界限均比较清晰。形态计量学研究为sect.Oligoneura甚至茜草属的物种鉴定与划分提供了重要的参考意义。 相似文献
3.
Four new dinoflagellates 总被引:1,自引:0,他引:1
Enrique Balech 《Helgoland Marine Research》1990,44(3-4):387-396
Fragilidium fissile is a new species of this rare genus. It somewhat resemblesF. subglobosum. It differs from the latter in having a slot and a pore in the first apical plate 1′ (the nomenclature of dinoflagellate
plate designation follows the Kofoid system). Both species are also distinguishable by noticeable differences in Po, 1″″ and
1‴.Peridinium tyrrhenicum is a small species differing from all the other known species ofPeridinium in its shape, apical channel and several plates, especially some of the sulcal components.Alexandrium foedum somewhat resemblesA. balechii, but it differs from the latter in that its width is greater than its length, and in the characters of all the main sulcal
plates. The above listed species were found in a sample from the Tyrrhenian Sea. The fourth species,Alexandrium andersoni, is a small dinoflagellate obtained in coastal waters off Cape Cod. It differs from all the other species of the minutum
group in the very typical shapes of both the 6″ and the S. s.Pentapharsodinium daleii Indelicato and Loeblich is transferred toPeridinium. 相似文献
4.
Jenő Kontschán 《Biologia》2013,68(1):150-154
A new Uropodina genus (Sinharaja gen. n.) is described on the basis of two new species (S. ceylonensis sp. n. and S. sinhala sp. n.) from Sri Lanka. The new genus differs by the strongly sclerotised dorsal lines, pentagonal pygidial shield, the shape and length of dorsal setae and the shape of first and fourth hypstomal setae, internal malae and epistome from the other known Uropodina genera. 相似文献
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Abstract A new species of Pyrus L. from the Nebrodi Mountains (northeast Sicily) is described, named, and illustrated. It differs from Pyrus spinosa in the shape and diameter/length ratio of its fruits and in the width/length ratio of the leaf lamina. An analytical key to the Pyrus species growing in Sicily is provided. 相似文献
7.
The new species Dionysia assadii (Primulaceae) from the Irano–Turanian region in Fars province, Iran, is described and illustrated. It is compared with its closest relative Dionysia esfandiarii Wendelbo and differs from it in leaf shape, leaf margin, hair density of leaves and other organs, shape of calyx and bracts, color of corolla and status of lobes, form and color of seeds, as well as the length of anthers and style in longistylous flowers. 相似文献
8.
Two new species of Leptolobium from Brazil are described and illustrated. Leptolobium araguaiense, restricted to northern Brazil, is similar to L. panamense, but differs in raceme length, ovary pubescence, flower and bract length, hilum shape, habit, geographical distribution, and
preferential habitat. Leptolobium multijugum, from midwestern Brazil, is perhaps most closely related to L. glaziovianum, but it has more numerous leaflets and smaller bracts and bracteoles than any other species in the genus. 相似文献
9.
Paul Wilkin John Burrows Sandie Burrows A. Muthama Muasya Erich van Wyk 《Kew Bulletin》2010,65(3):421-433
A new species of Dioscorea from South Africa, D. strydomiana Wilkin, is described and illustrated. It differs from the related species D. elephantipes (L’Hér.) Engl., D. hemicrypta Burkill and D. sylvatica Eckl. in its tuber surface, leaf morphology, texture and habit, male flower tepal, filament and pistillode size, the length
of the stipe between the ovary apex and the torus in female flowers and in capsule shape. Just two populations and c. 200
individuals in total exist, and significant threats have been reported, making D. strydomiana critically endangered. Thus its conservation and sustainable use are discussed. 相似文献
10.
该文描述了荨麻科三新种:(1)自中国重庆市发现的荨麻科荨麻属一新种,城口荨麻。此种与异株荨麻有亲缘关系,区别特征为此种的茎被少数刺毛,叶片多为心形,雄、雌花序均不分枝,瘦果在中央稍凹陷。(2)自中国广西发现的荨麻科赤车属一新种,来宾赤车。此种与特产云南东南部的富宁赤车相近缘,与后者的区别在于本种茎的毛开展或向上弯曲,叶片长椭圆形,基部斜楔形,雌花具3~4枚花被片,其中1~2枚较大花被片在背面顶端具一长筒状突起。(3)自缅甸北部发现的荨麻科楼梯草属一新种,克钦楼梯草。此种在体态上与骤尖楼梯草甚为相似,与后者的区别在于本种的每一茎节具正常叶和一退化叶,托叶狭披针状条形和无脉,雌总苞苞片无角状突起,雌小苞片较大,呈楔状长圆形,雌花具一小花被片,以及雌蕊具一宽倒卵球形柱头。 相似文献
11.
Carolyn Elinore Barnes Proença Lucia Helena Soares-Silva Pedro Ítalo Tanno Silva Suzane Margaret Fank-de-Carvalho 《Kew Bulletin》2010,65(3):463-468
Campomanesia cavalcantina Soares-Silva & Proen?a and Psidium ratterianum Proen?a & Soares-Silva (Myrtaceae), two new species from the Brazilian highlands are described and illustrated. Campomanesia cavalcantina is similar to Campomanesia eugenioides (Cambess.) D. Legrand var. eugenioides, but differs from this species in being an hemixyle, by the narrow to broadly elliptic-falcate leaves 1.7 – 4.6 times as long
as wide with 8 – 15 lateral veins, by the less densely glandular leaves and flowers, and by the lanceolate, c. 7 mm long bracteoles
which are persistent to young fruit stage. Psidium ratterianum appears to be most closely allied to P. australe Cambess. Both species share the hemixyle habit, similar leaf shape, leaf ratio and floral morphology. P. ratterianum differs from that species by its narrow, ascendant, strongly bullate leaves, bracteoles which are persistent in the fruit,
expanded, funnel-shaped stigma and smaller, elliptic fruits. Anatomically, Psidium ratterianum differs from other species of Psidium, and from other new-world Myrtaceae (Tribe Myrteae), in that the leaves are amphistomatic, a character known to occur in the
Australian genus Leptospermum. 相似文献
12.
The Malesian species of the predominantly New Caledonian genus Austrobuxus were revised. Three species are recognized. Austrobuxus nitidus is widespread from south Thailand to Borneo. Characteristic for this species are the very short papillae of the caruncle. The caruncle papillae are much longer in the other two, newly described species. Austrobuxus celebicus sp. nov. is endemic to Sulawesi, where it is found on ultramafic soils, and A. dentatus sp. nov. is an endemic species of western New Guinea. The former is notable for the very small fruits and the latter for the teeth‐like glands along the leaf blade margins, unique within the genus. 相似文献
13.
Eight species of the genus Monhystrella, six of which are new to science, are described from bottom samples collected from three lakes, two rivers and a hot spring in Ethiopia. Monhystrella hoogewijsi n. sp. is identified by a distinctive bulge on the lip region, position of the amphids, offset and well developed single pharyngeal terminal bulb, tail shorter than vulva-anus distance, tail elongate-conoid for two-thirds of its length, and by the shape and size of the spinneret outlet; M. jacobsi n. sp. by its slender body, distinctively offset and distended lip region, indistinct and weakly expanding single terminal pharyngeal bulb, and shape and size of the tail and spinneret outlet; M. arsiensis n. sp. by its single terminal pharyngeal bulb, position of amphids, shape and length of tail and spinneret outlet; M. woitorum n. sp. by its hemispherical lip region, double terminal pharyngeal bulb, shape and length of the spinneret outlet, and shape and length of tail; M. ethiopica n. sp. by its bipartite stoma, size of amphid in relation to corresponding body width, filiform tail and shape and length of spinneret outlet. M. atteae n. sp. differs from all known Monhystrella species in having an inflated cap-like lip region and fine crystalloid bodies. M. macrura (de Man, 1880) Andrássy, 1981 and M. lepidura altherri (Juget, 1969) Jacobs, 1987 are reported from Ethiopia for the first time. Crystalloid bodies in the genus Monhystrella is reported here for the first time. Also the presence of a hyaline coelomocyte next to the germinal zone of the reproductive system is reported for the first time in the genus here in all eight species. The structures used in the taxonomy of the genus are reviewed. 相似文献
14.
A new genus and two new species of free-living marine nematodes from sediments in the coastal zone of the South China Sea
(Vietnam) are described. Cyartonemoides gen. n. morphologically resembles Cyartonema Cobb, 1920, but differs from it in having a well-developed cephalic capsule. Cyartonemoides foetidus gen. n., sp. n. is the type and the only species of the genus. Campylaimus abnormis sp. n. differs from all species of the genus Campylaimus Cobb, 1920 by the shape of the amphidial fovea and shorter lateral fields. 相似文献
15.
H. KURZWEIL H. P. LINDER W. L. STERN A. M. PRIDGEON 《Botanical journal of the Linnean Society. Linnean Society of London》1995,117(3):171-220
The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber (‘polystelic’ or ‘monostelic’). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and ‘polystelic’ tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa. 相似文献
16.
ZHANG Li‐kun 《Insect Science》2000,7(4):311-314
Abstract This paper deals with a new species of Iowana Hottes, Icrwana zhangi, sp. nov. in China. This new species is closely related to J. frisoni, but differs from the latter in the shape of cauda, length of processus terminalis, length of ultimate rostral segment, and as well as in having smooth siphunculi, having 6‐segmented antennae and primary rhinarium with accessory rhinaria on the ultimate antennal segment. All the type specimens of this new species, collected from Heilongjiang Province, are deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing. Iowana Hottes is a new record genus to China. 相似文献
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18.
The tropical Indo-Pacific genus Excoecaria L. (Euphorbiaceae) has several closely related species in Australia whose taxonomic relationships are unclear. The most widely reported species in Australia is the mangrove species Excoecaria agallocha L. (type species), whose taxonomic and geographic limits are difficult to define from its closely related species or sub-species. Two additional taxa have also been described but not clearly differentiated from the type species: Excoecaria dallachyana Baillon and Excoecaria ovalis Endl. This project aimed to determine the taxonomic relationships of the Australian Excoecaria species using both leaf morphological data and DNA sequence data from the internal transcribed spacer (ITS) region of ribosomal genes. The nucleotide differences in the examined ITS1 region show that E. agallocha from eastern Australia and E. ovalis from Western Australia respectively, are genetically uniform within species but differ from each other consistently, thus supporting species status. The leaf morphological data also support this view: single factor analysis of variance consistently separated E. ovalis from E. agallocha on the basis of leaf width, leaf length and length of petiole. In contrast, E. ovalis from the Gulf of Carpentaria differs only slightly from E. ovalis in Western Australia, but no evidence was found to suggest any leaf morphological differentiation within this species. The analysis also suggests that E. dallachyana is not closely related to either mangrove species E. agallocha or E. ovalis, despite superficial morphological similarities. 相似文献
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20.
Guy Oliver 《Systematic parasitology》1986,8(4):317-322
Summary
Cycloplectanum riouxi n. sp., described here, resembles Cycloplectanum amplidiscatum (Bravo-Hollis, 1954) Beverley-Burton & Suriano, 1981 and Cycloplectanum beverleyburtonae Oliver, 1984 in the shape of the sclerified cirrus bulb and resembles Cycloplectanum americanum (Price, 1937) Oliver, 1968 in the shape of the vaginal sclerifications. It differs from these species in the shape of the haptoral transverse bars and the morphology of the squamodiscs. It differs also from other species of the genus Cycloplectanum Oliver, 1968 in the shape of the vaginal sclerifications. 相似文献