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1.
Foliar appendages of eight species ofSalvia L. have been studied. Eleven types of non glandular and five types of glandular appendages have been observed. They have been classified under three major categories: (1) glandular capitate; (2) non glandular filiform and (3) non glandular capitate. Five new types of trichomes have been reported fromLamiaceae for the first time. On the basis of trichome types different species ofSalvia can be identified. A tentative key has been presented. 相似文献
2.
Ricardo de S. Secco 《Brittonia》2004,56(4):353-356
A new species ofCroton,C. dissectistipulatus, is described from Amazonian Brazil. This species is superficially similar toC. timandroides from northeastern and southeastern Brazil, but differs in having petiolate leaves with glandular margins, persistent stipules, conspicuous racemose inflorescences, staminate flowers having externally glabrous sepals and 3 stamens, and pedicellate pistillate flowers. The systematic position ofC. dissectistipulatus relative to the sections ofCroton is discussed. 相似文献
3.
A new species ofCestrum from the Cordillera de Mérida in Trujillo state is described and illustrated.Cestrum darcyanum, morphologically similar toC. microcalyx Francey, is distinguished by dendritic pubescence on its branchlets and leaves, larger corolla, stamens distended and geniculate
above their point of adnation to the corolla, and larger calyx. A key is provided for species of VenezuelanCestrum possessing dendritic pubescence. 相似文献
4.
Gerald A. Wheeler 《Brittonia》1986,38(4):317-324
Two new species ofCarex (Cyperaceae) are described from southern South America.Carex transandina occurs in naturally-deposited rock talus and scree in southwestern Chile andC. austroamericana occurs in the Patagonian steppe in Chile and Argentina. In the past, specimens ofC. austroamericana have been erroneously referred toC. andina var.subabscondita Kük., and it is shown here that the latter entity is conspecific withC. nelmesiana Barros. The taxonomy ofC. nelmesiana is presented and its relationship to other members ofCarex sect.Junciformes (Boeckl.) Kük. is discussed. 相似文献
5.
Width-to-length ratios of upper stem leaves ofLasallea novaeangliae andL. oblongifolia were determined from herbarium specimens and field collections. No distinct subgroups based on suchratios were found in either species. InL. novaeangliae the curve of the ratio versus number of individuals was skewed toward the narrow-leaf range. This phenomenon was present but less pronounced inL. oblongifolia. The histogram of leaf ratios forL. novaeangliae was somewhat weakly bimodal, suggesting a possible broad-leaf race, which has not been recognized nomenclaturally. The absence of bimodality in the histogram of leaf ratios forL. oblongifolia indicates the need to place Shinners’ narrow-leaved varietyangustatus in synonymy. Other traits such as height, degree of branching and the nature of the pubescence were also found to be of no significance. Slight geographic trends in leaf width occur in both species. No real evidence was found for nomenclaturally recognizing any eastern variant in either species. Thus, Shinners’ var.orientis is not recognized inL. oblongifolia either. 相似文献
6.
L. Alan Prather 《Brittonia》1996,48(1):111-119
Revisionary work has revealed three new species ofCobaea:Cobaea flava of northern Peru,C. paneroi of central Mexico, andC. rotundiflora of Guatemala and extreme southeastern Mexico.Cobaea flava is most similar toC. campanulata and differs mainly in its pedicel pubescence, corolla coloration, and stamen position.Cobaea paneroi is among the large-flowered species (theCobaea scandens group) but is easily distinguished from these by its long-acuminate calyx segments.Cobaea rotundiflora most closely resemblesC. triflora. It differs mainly in its corolla coloration and wider, pubescent calyx segments. 相似文献
7.
Six interspecific backcross prog enies were generated by crossing hybrids ofC. saluenensis XC. japonica (C. Xwilliamsii) back toC. japonica. Segregation data were obtained within these six families for five traits, three involving flavonoid constituents and two pubescence characters. A single major gene seemed to be primarily involved in each case, and two of the traits exhibited linkage behavior. The taxonomic value of such marker traits is discussed. 相似文献
8.
该文描述了发现自中国新疆天山北部的毛茛科乌头属一新种,即乌鲁木齐乌头(Aconitm urumqiense),此新种与新疆乌头(A. sinchiangense)近缘。两者的区别在于此新种(乌鲁木齐乌头)的茎无毛,不存在基生叶,总状花序轴和花梗被黄色腺毛,萼片背面疏被柔毛、边缘被缘毛,上萼片较宽,花瓣唇在顶端啮蚀状,子房幼时疏被柔毛。 相似文献
9.
Arbuscular mycorrhizal colonization of the dominant plant species in primary successional volcanic deserts on the Southeast slope of Mount Fuji 总被引:3,自引:0,他引:3
Arbuscular mycorrhizal (AM) colonization was observed on four plant species in primary successional volcanic deserts on the Southeast slope of Mount Fuji. The AM colonization of the dominant species, Polygonum cuspidatum, contradicts the conclusion that Polygonaceae are often regarded as being non-mycorrhizal species. The secondary dominant species, Polygonum weyrichii var. alpinum, formed no mycorrhizas. The roots of Cirsium purpuratum, Clematis stans and Campanula punctata ssp. hondoensis, showed a higher percentage of AM colonization than P. cuspidatum. AM colonization and spore density in the rhizosphere soil of P. cuspidatum significantly decreased as elevation increased. AM colonization in roots of Cirsium purpuratum and Clematis stans also tended to decrease with increased altitudes. Cirsium purpuratum and Campanula punctata ssp. hondoensis formed single structural types of Arum- and Paris-type, respectively, whereas P. cuspidatum and Clematis stans formed both Arum- and Paris-type morphologies. 相似文献
10.
David A. Young 《Brittonia》1974,26(3):241-255
Five populations ofRhus integrifolia andR. ovata were studied and, based upon morphological characteristics and pollen viability, a number of putative hybrids were found in those areas where the two species are sympatric. Diagnostic characteristics most useful for distinguishing the species and their hybrids are leaf morphology, sepal pubescence, petiole length, and petal size. Introgression was evident in at least three populations, which suggested that hybridization between the two species is an ancient phenomenon. Evolutionarily, hybridization between the two taxa has probably been of little consequence. 相似文献
11.
Lynn Bohs 《Economic botany》1989,43(2):143-163
Plants of the genusCyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo,Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South America and is now dispersed worldwide in subtropical areas. Its origin and wild relatives are still unknown, but there are tentative reports of wild populations ofC. betacea in southern Bolivia and northwestern Argentina. Wild species ofCyphomandra such asC. hartwegii, C. sibundoyensis, andC. cajanumensis also produce edible fruits. Other species ofCyphomandra are used in medicinal preparations and as dyes. This group of plants is of increasing economic importance and may have considerable potential for future exploitation. 相似文献
12.
Background
Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis.Methodology/Principal Findings
We conducted a “total evidence” analysis combining nuclear (ncpGS, ITS) and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL) DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12) and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04±0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments). A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence). Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.Conclusions/Significance
The observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion) in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group. Key innovation of morphological characteristics is supported by our dated phylogeny, in which a Mediterranean climate establishment (2.8 Ma) predated the adaptive radiation of the white-flowered Cistus. 相似文献13.
Theodore S. Cochrane 《Brittonia》1981,33(2):225-232
Carex hermannii, a new species known only from a few populations on large volcanic mountains on the Puebla-México state border, central Mexico, is described, illustrated and compared with its nearest relative,C. cuchumatanensis of Guatemala. Both these species have been confused until now with the more distantly relatedC. endlichii. Morphological comparisons ofC. hermannii, C. cuchumatanensis andC. endlichii confirm the distinctiveness of these species. 相似文献
14.
P. Le Fras. N. Mouton Alexander F. Flemming C. Alexander Searby 《Journal of morphology》1998,235(3):177-182
Generation glands are holocrine epidermal glands occurring on the ventral aspect of the thigh of cordylid lizards. In most species these glands seemingly start to differentiate with the onset of sexual maturity, but macroscopic signs of generation gland activity were noted in neonates of the large-scaled girdled lizard, Cordylus macropholis. The glands of neonatal, subadult, and adult individuals were examined microscopically using standard histological techniques. The glands of the five neonatal specimens examined, including both males and females, all had the same basic structure and displayed two layers of mature glandular material. In subadult and adult specimens, the number of layers varied from seven to nine. The structure of the generation glands of C. macropholis is similar to that of the few other Cordylus species that have been described to date. They are of the protruding kind with multiple mature glandular generations. Juveniles of an additional 12 cordylid species have been examined for the presence of active generation glands. Active glands were found to be present in neonates of C. tasmani and C. tropidosternum, both of which are, like C. macropholis, terrestrial species. In C. cordylus and C. coeruleopunctatus, active generation glands are absent in neonates, but differentiate soon after birth. In other cordylid species, generation glands apparently differentiate only with the onset of sexual maturity. J. Morphol. 235:177–182, 1998. © 1998 Wiley-Liss, Inc. 相似文献
15.
16.
The community-wide and guild-specific effects of pubescence on the folivorous insects of manzanitas Arctostaphylos spp. 总被引:2,自引:0,他引:2
Abstract. 1. Insect communities on 26 species of manzanita Arctostaphylos spp. (Ericaceae) were sampled in order to examine the effects of variation in foliar pubescence traits on a community of folivorous insects. Manzanitas vary widely in pubescence density, length, and glandularity both within and between species.
2. Linear models were fitted and evaluated to determine whether pubescence traits are associated with the species richness and abundance of folivorous insects after accounting for the effects of other relevant habitat and host-plant related characteristics.
3. Pubescence traits were clearly associated with both community-wide and guild-specific variation in the structure of the folivorous insect community of manzanitas, however the effects of pubescence were manifested primarily as effects on the abundance of folivores not on species richness. The species richness of folivorous insects on manzanitas was not associated with pubescence density or length but was associated positively with glandularity.
4. The abundance of all guilds except leaf-mining insects was lower on manzanitas having longer pubescence. In contrast, the abundance of external-chewing insects was higher on plants having denser pubescence and on plants having glandular pubescence.
5. Overall, the results suggest that both longer pubescence and the amount of contact between an insect and pubescence act quantitatively to decrease the abundance of external-feeding guilds of folivorous insects. The abundance of species in internal-feeding guilds that oviposit directly on leaves is unrelated to foliar pubescence traits in the host plant. 相似文献
2. Linear models were fitted and evaluated to determine whether pubescence traits are associated with the species richness and abundance of folivorous insects after accounting for the effects of other relevant habitat and host-plant related characteristics.
3. Pubescence traits were clearly associated with both community-wide and guild-specific variation in the structure of the folivorous insect community of manzanitas, however the effects of pubescence were manifested primarily as effects on the abundance of folivores not on species richness. The species richness of folivorous insects on manzanitas was not associated with pubescence density or length but was associated positively with glandularity.
4. The abundance of all guilds except leaf-mining insects was lower on manzanitas having longer pubescence. In contrast, the abundance of external-chewing insects was higher on plants having denser pubescence and on plants having glandular pubescence.
5. Overall, the results suggest that both longer pubescence and the amount of contact between an insect and pubescence act quantitatively to decrease the abundance of external-feeding guilds of folivorous insects. The abundance of species in internal-feeding guilds that oviposit directly on leaves is unrelated to foliar pubescence traits in the host plant. 相似文献
17.
A morphological and chemical analysis of geographical variation in Tilia L. of eastern North America
A statistical analysis of morphological variation and a Chromatographic analysis of flavonoid variation were performed to determine taxonomic relationships among the species ofTilia of eastern North America. No apparent morphological discontinuities were seen between populations within the sample area although two characters (involving leaf pubescence and gland length) showed definite patterns of geographical variation. Flavonoid patterns showed definite differences between northern and southern populations with an intermediate zone in the Smoky Mountain region. The continuous nature of the morphological and flavonoid variation suggested that the genus as represented in eastern North America should be regarded as one species,Tilia americana L. 相似文献
18.
Marie Lhotská 《Folia Geobotanica》1974,9(3):231-240
Experimental stratification and sowing-out of achenes ofChaerophyllum bulbosum L.,Clematis vitalba L. andHedera helix L., collected at various periods of the year, confirmed the opinion that, in species with hemibradysporic to bradysporic dissemination, the after-ripening of embryos takes place not only within the soil and during stratification, but under favourable conditions also directly on the mother plant. In seeds with dry pericarp, the after-ripening takes place under the influence of atmospheric moisture, while in fleshly fruits the same process develops under the influence of water absorbed from the fleshy part of the pericarp. 相似文献
19.
Cecilia M. Krmpotic Fernando C. Galliari Claudio G. Barbeito Alfredo A. Carlini 《Mammalian Biology》2012,77(5):314-326
The integument of extant armadillos (Xenarthra, Cingulata) is a unique organ in which complex glandular systems are associated with pilose follicles, dermal ossifications, and cornified scales. Up to date, papers have focused on neither comparative morphology of the skin (dorsal and ventral) nor chronology of the development of interspecific homolog structures. In order to clarify the way in which events occur during development of the integument structures, maturity of other tissues (e.g. skeletal tissues) should be considered. Therefore, we will be able to identify events that have been pre- or post-displaced during ontogenetic development. The aim of this paper is to describe in a developmental and comparative framework the integumentary system of neonates of Dasypus hybridus and Chaetophractus vellerosus. In order to understand the morphology of the different integumentary structures serial histological sections were prepared. Staining techniques included H–E, Masson Trichrome, PAS, orcein and reticulin. To study ossification of postcranial elements, the specimens were cleared and double-stained with alcian blue and alizarin red. Determinations of ossification centers and their progress were recorded through the early uptake of alizarin. The dorsal dermis of neonates from D. hybridus is clearly differentiated into a superficial and deep layer, as in fetuses of Dasypus novemcinctus. In C. vellerosus, however, these layers could not be identified. This suggests a less connective tissue differentiation in the latter species at this stage. Osteoderms in D. hybridus are well differentiated unlike C. vellerosus where no condensations of osteoprogenitory cells are observed. Conversely, pilose follicles and glandular tissues are less developed in D. hybridus. Regarding postcranial elements, ossification centers are less advanced in C. vellerosus than D. hybridus, this is particularly notorious for the vertebral column, sternal, and pelvic girdle elements. Asynchronies between neonates of both species observed on integumentary and postcranial skeletal tissues could match with specific adaptive strategies related to distribution in different environments, and/or different postnatal care. 相似文献