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71.
本文报道连香树木材解剖和扫描电镜研究结果,连香树木材特征较为原始,具导管和管胞,导管端壁斜、梯状穿孔板、具有超出穿孔板的三生螺旋加厚,管胞为原始的梯纹管胞,木纤维壁上具裂隙状纹孔,木薄壁组织离管型,星散状分布,木射线异型。 相似文献
72.
J. K. JARVIE F.L.S. MARY E. BARKWORTH F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1992,108(3):287-301
JARVIE, J. K. & BARKWORTH, M. E., 1992. Anatomical variation in some perennial Triticeae. Cross-sectional anatomy of glumes and leaf blades was examined in 22 taxa of the perennial Triticeae. The taxa included diploids and polyploids based largely on various combinations of the E, J and S genomes. The objective was to determine how much correlation exists between anatomical characteristics and genomic constitution. The data were analysed by principal co-ordinate and cluster analyses. The results showed that monogenomic species based on different genomes were readily distinguishable on glume and leaf blade features. Most heterogenomic taxa exhibited some aspects of each genome present except in the case of JE allotetraploids, which exhibited no E genome characteristics. 相似文献
73.
Dry matter and nutrient inputs through litter fall in a dry tropical forest of India 总被引:1,自引:0,他引:1
Lalji Singh 《Plant Ecology》1992,98(2):129-140
The present paper elucidates the pattern of leaf and non-leaf fall and quantifies of the total annual input of litter in a dry tropical forest of India. In addition, concentration of selected nutrients in various litter species and their annual return to the forest floor are examined. Total annual input of litter measured in litter traps ranged between 488.0–671.0 g m-2 of which 65–72% was leaf litter fall and 28–35% wood litter fall. 73–81% leaves fall during the winter season. Herbaceous litter fall ranged between 80.0–110.0 g m-2 yr-1. The annual nutrient return through litter fall amounted (kg ha-1): 51.6–69.6 N, 3.1–4.3 P, 31.0–40.0 Ca, 14.0–19.0 K and 3.7–5.0 Na, of which 71–77% and 23–29% were contributed by leaf and wood litter fall, respectively for different nutrients. Input of nutrients through herbaceous litter was: 13.0–16.6 for N, 1.0–1.4 for P, 4.0–5.0 for Ca, 7.9–10.5 for K and 0.8–1.0 kg ha-1 yr-1 for Na. 相似文献
74.
75.
The usefulness of features of leaf hairs in distinguishing subgenera and sections is well documented in bothRhododendron andSolanum. In this analysis of the taxa ofSolanum sect.Basarthrum (23 species), and of a sample of closely related taxa from sect.Petota (22 species), it is shown that such features serve to delineate subsectional groups such as series and some species as well. SectionBasarthrum has an unexpected diversity of hair types. Although this group has been characterized by 2-celled bayonet hairs, more than one half of the taxa in the section bear multicellular finger hairs, and 3 species also possess branched hairs. Thus, major rearrangements of the species previously assigned to sect.Basarthrum are indicated or supported by pubescence features. The taxa studied from seriesEtuberosa andJuglandifolia (both of sect.Petota) show hair types that a) are relatively primitive for the section, and b) show linkage between sects.Petota andBasarthrum. 相似文献
76.
Charles E. Oxnard 《American journal of physical anthropology》1981,54(1):1-21
The aberrant features of the genus Daubentonia, such as the superficially rodent-like dentition, the globose and foreshortened brain case, and the filiform third manual digit have long been known. But the current assessment of the genus as lemuriform, and within that group as closest to the indriids, depends upon greater weight being placed upon other characteristics such as the cranial arterial pattern, the molariform teeth, and the developmental characteristics of the dentition. Prior multivariate morphometric studies have shown that though the shoulder structure of Daubentonia is uniquely different from that of all other primates, the structure of its pelvis may not be especially different from that of many relatively non-specialized primates. A large series of studies have been summated here in which many different anatomical regions (shoulder, arm, forearm, forelimb as a whole, pelvis, femur, hindlimb as a whole, forelimb and hindlimb combined, and total bodily proportions including limbs, trunk, and head) have been characterized osteometrically in a wide range of primate genera. The resulting data sets have been studied by discriminant function analyses. The differences that have been found are large enough that it can be confidently asserted that in its postcranial skeleton, Daubentonia is more different from the primates as a whole than is any other primate genus. These differences are big enough that their statistical and biological significance is not at all in doubt, notwithstanding the very small numbers of available specimens of this rare genus. They are so great that functional implications exist though they cannot, in our present state of knowledge of the habits of the genus, be ascribed with any certainty. They are so great indeed, paralleling the enormous differences of Daubentonia from other primates in its dentition, skull and cheiridia, that we may prefer to keep open minds about its taxonomic placement. 相似文献
77.
Cranial morphology and adaptations in Eocene Adapidae. II. The Cambridge skull of Adapis parisiensis
One of the most complete skulls of the early primate Adapis parisiensis is in the collection of the Department of Zoology, Cambridge University. This exceptionally well-preserved male skull, from Quercy in southern France, is important in showing relatively small orbits that are highly convergent, a distinct ethmoid component in the medial orbital wall, very small infraorbital foramina, a well-preserved auditory region with the stapedial canal about twice the diameter of the canal for the promontory artery, and a well-preserved braincase 8.8 cm3 in endocranial volume. The frontal lobe of the brain in the Cambridge skull described here is less expanded than that reported previously in a British Museum skull. The average body weight of Adapis parisiensis is estimated to have been about 2.0 kg, and that of Adapis magnus is estimated to have been about 8.4 to 9.0 kg. The encephalization quotient (EQ) of Adapis parisiensis is estimated to have been 0.45, which is well below the range found in modern prosimians. There is some indication that the size of the foramen magnum has increased with increasing brain size during primate evolution. Adapis parisiensis appears to have been a medium-sized, visually oriented, diurnal, sexually dimorphic arboreal folivore. 相似文献
78.
C. A. STACE F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1980,81(3):185-203
The anatomy of the leaf epidermis of 49 of the approximately 65 African species of Combretum subgenus Cacoucia is described. This is discussed in relation to the taxonomy of the subgenus, particularly its sectional classification. Of the 17 sections which have been describrd, Campylogyne is now referred to the genus Quisqualis, Argyrotricha is referred to Combretum subgenus Combretum , and Angolensia, Grandiflora, Mweroensia, Parvula and Trichopetala are included with other sections. Combretum grandidieri is referred to the genus Calopyxis . In general the leaf epidermis of speries of subgenus Cacoucia is of far lower taxonomic value than in subgenus Combretum . 相似文献
79.
JOHNT. SORENSEN 《Zoological Journal of the Linnean Society》1980,70(1):55-101
An integumental anatomy for the lycaenid butterfly Glaucopsyche lygdamus is presented. Comparisons with other lepidopteran taxa are made to rectify the homology of parts and contrast anatomical divergences within the Lycaenidae. A general terminology based on Snodgrass is given, to replace many of the specialized and often synonymous terms restricted to the Lepidoptera. Many common anatomical svnonyms are also given. Several reinterpretations of the anatomy and homology of various integumental regions are discussed. A previously unreported cuticular anomaly on abdominal tergum 2 of male Polyommatinae (Downey's area) is described. The following new or newly combined terms are used:postgenal-occipital area, postgenal-occipital protuberance, dorsal temporal sulci, postantennal projections, pronotal projection, infraepisternal-basisternal plate, paracoxal-marginopleural sulci, dorsal epimeral sulci, ventral epimeral sulci, secondary coxal sulci, ventral subcostal-radial process, lateral secondary sclerite and Downey's area. 相似文献
80.
The cladistic relationships of Archaeopteryx , the earliest known bird, are re-examined and previous hypotheses of relationships evaluated. The morphology of Archaeopteryx is redescribed. New interpretations of the fossils are presented, particularly in regard to the morphology of the pectoral girdle, manus, pelvic girdle, tarsus and pes. These new interpretations challenge some of the phylogenetic hypotheses recently presented and a new version of thecodontian relationships is suggested. 相似文献