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1.
马毓泉 《中国科学院研究生院学报》1951,1(1):5-19
Gentiana was originally proposed by Tournefort in 1700. Linnaeus adopted this generic name in his “Genera Plantarum” published in 1737. He divided the genus into seven groups on the basis of different shapes of corolla and forms of floral appendages. In his “Species Plantarum” he reorganized them into three artificial ones. Forty years later, Moench established a new genus, Gentianella under which he described G. tetrandra as the type of his new genus. In the view of identity of Gentianella tetrandra with Gentiana campestris L., it is evident that Gentianella represents only some plants formerly included in Gentiana at Linnaeus time. In 1796, Froelich’s monograph on Gentiana appeared. In his work four sections were represented and one of them was Crossopetalum. In 1845, Grisebach also published a monograph of Gentianaceae and recorded fifteen sections of which Amarella and Imaicola are two of his seven proposed ones. In 1888, Huxley studied the floral structure of Gentianaceae in relation with pollination mechanism and, accordingly, divided the family into two main groups, one with epipetalous glands, the other with glands at the base of the ovary. In each group, four types of flowers were found. He concluded that Gentiana was a complex genus on account of presence of four different types of flowers in this group, and suggested that many species of the genus should be separated out to form some smaller generic categories. Six years after, Kusnezow in his monograph divided Gentiana into two subgenera Eugentiana and Gentianella. In his system, subgenus Eugentiana consists of ten sections and the Gentianella, seven. He contributed much to the systematic treatment of Eugnetiana but little to that of Gentianella. He maintained the genus Gentiana in a broad sense. With increased knowledge of this group in the last thirty years, a number of botanists were able to make a clearer delimitation of true Gentiana and its allies and treated them in more natural way. Moench’s genus Gentianella was rerised. In 1936, H. Smith separated Megacodon from Gentianella as a genus. In the present paper, the writer suggests a generic name Gentianopsis for the section Crossopetalum in the same Genus.
This new genus is characterized by (1) its large and somewhat flattened ellipsoidal flower bud, (2) two dissimilar pairs of calyx lobes which are distichously imbricate in aestivation, (3) four triangular, ciflated intracalyx membranes at the base of and alternate with the calyx lobes, (4) distinct gynophore and (5) enlarged stigma. While in typical Gentianella represented by section Amarella, the flower buds are small and terete, a laciniate corona is usually present, and the calyx-lobes are leafy, lanceolate, imbricate, and not provided with intracalyx membrane.
Besides the morphological characters mentioned above, the anatomical structure of
the floral parts is also a significant generic criterion. In Gentianopsis, eight vascular
bundles are present in calyx, representing four dorsals and four fused ventrals. In each
corolla-lobe there are five bundles. In the body of ovary six bundles are present. The
ovule bearing surface is extensive covering nearly to entire surface of the ovary wall with
the exception of a narrow longitudinal zone along the dorsal bundle. In Gentianella,
calyx bundles are three in each lobe, without fusion of the ventrals. In each corolla-
lobe, the bundles are three instead of five as in Gentianopsis but the lateral ones branch
once dichotomously after entering the base of corolla. In the body of ovary only four
main bundles are present due to the fusion of smaller ventral ones. The placentation
is confined to the region of the ventral bundles.
Phylogenetically Gentianopsis and Gentianella may be regarded as closely reIated
and may represent branches of a common line with Gentianopsis standing at a lower
level, Gentianella being more advanced. In Gentianella the number of bundles in the
corolla segments and ovary wall are reduced by partial or complete fusion and the
distribution of ovules is confined only to the region of the ventral bundles. However,
in the calyx of Gentianopsis there is fusion of ventral bundles, whereas the correspound-
ing bundles in the Gentianella remain separate. The Gentianopsis-Gentianella line on
the one hand and the Gentiana line on the other may come again from a common
acestral stock. Gentiana possesses only three bundles in each corolla-lobe. A variety
of plicate between corolla lobes except in case of Gentiana lutea and intracalyx membrane
above the throat of calyx-tube are also the common structures in Gentiana. Thus the
pollination mechanism is highly specialized in the genus. As far as we know, in
Gentiana the glandular appendages usually exist at the base of ovary. If those nectarial
processes are correctly interpreted as the representatives of staminodes, gentiana would,
undoubtedly, be derived from an ancestral form with hypogynous diplostemonous
androecium, and bears no direct relationship to Gentianopsis or Gentianella in which the
glands are epipetalous. It may be reasonable to conclude the Gentiana and Gentianopsis-
Gentianella line are two parallel derivatives from a common ancestor which has the
floral characters of two series of hypogynous stamens. Gentianopsis and Gentianella may
represent branches of a common line with Gentianopsis standing at a lower level,
Gentianella being more advanced. Their relations may be diagrammed below:
Gentianopsis
Gentianella
Common ancestor
Gentiana
This new genus consists of fourteen species and two varieties in the world. Onlyeight species and two varieties are represented in China. They are G. barbara, G. barbatavar. sinensis, G. grandis, G. scabromanginata, G. paludosa, G. nana, G. longistyla,G. lutea, G. contorta, and G. contorta var. Wui. The species of present genus occur in the alpine regions of North Hemisphere. InChina t,hey are distributed in Kokonor, Kansu, Shensi, Shansi, Chahar, Hopei, Manchuria,Hupeh, Szechuan, Sikang, Tibet, and Yunnan. G. Yabei (Takeda et Hara) is foundin Japan, G. detonsa (Bott&) in North Europe, G. ciliata (Linn.) in South Europe,G. crinita (Froel.) G. procera (Holm.) and G. degans (A. Nels) in North America.G. barbata is the most widespreading species and reported in Sibiria and China.G. contorta (Royle) is a common plant in Himalayan mountaineous range, China andNorth part of India. The species and varieties cited in this paper are as follows:
t. Gentianopsis barbata (Froel.) comb. nov.
la. Gentianopsis barbata (Froel.) var. sinensis, var. nov.
2. Gentian opsis grandis (H. Sm.) comb. nov.
3. Gentianopsis scabromarginata (H. Sm.) comb. nov.
4. Gcntianopsis paludosa (Munro) comb. nov.
5. Gentianopsis nana sp. nov.
6. Gentianopsis longistyla, sp. nov.
7. Gentianopsis lutea, sp. nov. 相似文献
2.
3.
4.
The present paper describes the pollen morphology of 30 species belonging to 7 genera of Plumbaginaceae from China. The pollen grains were all examined under light microscope, and those of some species under scanning and transmission electron microscope.
The pollen grains of the family are subspheroidal, prolate or oblate, (37.5-74.5)× (40.4-81.9)μ in size, 3-colpate, rarely 4-6-colpate, only pancolpate in Ceratostigma willmottianum. The exine 2-layered, 2.0-7.4μ thick, sexine thicker than nexine, verrucate, reticulate or coarsely reticulate.
On the basis of the morphology, two types of pollen grains are distinguished in the
family:
(1) The pollen grains are 3-(rarely 4-6 ) or pancolpate, the exine verrucate. They are found in the tribe Plumbagineae (inculuding the genera Ceratostigma, Plumbago and Plumbagella).
(2) The pollen grains are all 3-colpate, the exine reticulate or coarsely reticulate. They are found in the tribe Staticeae (including the genera Acantholimon, Ikonnikovia, Goniolimon and Limonium ). 相似文献
5.
6.
张志耘 《中国科学院研究生院学报》1988,26(5):394-403
The morphological characters in the genus Orobanche were evaluated from the
taxonomic point of view. The author finds that the plants of this genus are relatively similar
to each other in respect to characters of vegetative organs, fruits and seeds. But the differences
in the floral structures can be served as a basis for delimitating infrageneric taxa. The seed
coat of 18 species and pollen grains of 6 species were also examined under scanning electron
microscope (SEM). They seem to have little significance for distinguishing species.
The result supports G. Beck’s (1930) division of the genus Orobanche into 4 sections, of
which 2 occur in China, based on the characters of the inflorescence, bracteoles and calyx.
The author considers that some characters, such as anther hairy or not, upper lip of corolla
entire or not, lower lip longer or shorter than the upper one, the state of corolla-tube inflec-
tion and the hair type of filaments and plants, are important in distinguishing Chinese species.
A key to the species of Orobanche in China is given.
This genus consists of about 100 species, and is mostly confined to Eurasia, with over 60
species found in Caucasus and Middle Asia of USSR, where may be the mordern distribu-
tional centre.
Orobanche L. in China is represented by 23 species, 3 varieties and l forma. As shown in
Table 1, most species (12 species) are found in Xinjiang, which clearly shows a close floristic
relationship between this region and Middle Asia of USSR. 6 species are endemic to China,
of which 4 are confined to the Hengduan Mountains (Yangtze-Mekong-Salwin divide).
The relationships between this genus and related ones of Orobanchaceae are also discussed.
The author holds the following opinions: the genus Phelypaea Desf. should be considered as a
member of Orobanche L. Sect. Gymnocaulis G. Beck, the monotypic genus, Necranthus A.
Gilli endemic to Turkey, is allied with Orobanche L. Sect. Orobanche, the monotypic genus,
Platypholis Maxim, endemic to Bonin Is. of Japan, is far from Orobanche L. in relation and
should be regarded as a separate genus.
The 11 OTU’s, including all the sections of Orobanche L. and 7 genera of Orobanchaceae,
and 15 morphological characters were used in the numerical taxonomic treatment to test the
above-mentioned suggestions. After standardization of characters, the correlation matrices were
computerized. The correlation matrices were made to test the various clustering methods. At
last the UPGMA clustering method was chosen and its result is shown in a phenogram. The
result of numerical analysis is basically in accordance with the suggestions. 相似文献
7.
The pollen morphology of 11 species and 1 variety in the genus Lespedeza and its
allied genera (Campylotropis, Kummerowia) from NE China was examined under light and
scanning electron microscopes.
1. Lespedeza Michx. (plate 1:1-6; 2:1-6; 3:1-6; 4:1-2)
Pollen grains prolate, rarely subprolate or spheroidal, elliptic or rarely suborbicular in equa-
torial view, 3-lobed-rounded in polar view, tricolporate, colpus margins smooth or jagged. Polar
axis 20.7-33.1μm long, equatorial axis 15.4-20.9 μm long. Exine reticulate or foveolate, lu-
mina verrucose or smooth under SEM.
2. Campylotropis Bge. (plate 4:3-4)
One species in NE China, C. macrocarpa (Bge.) Rehd. Pollen grains prolate, elliptic in
equatorial view, 3-lobed-rounded in polar view, 3-colporate, colpus linear, 25.1μm long, 1.79μm
broad, colpus margins jagged, with a series of verrucae equal in size along one side visible
under SEM. Polar axis 19.7μm long, equatorial axis 14.6μm long. Exine reticulate, lumina
nearly rounded, verrucose at periphery under SEM.
3. Kummerowia Schindl. (plate 4:5-6)
Pollen grains spheroidal, oblate or prolate, elliptic in equatorial view, obtuse-triangular in
polar view, tricolporate, colups linear, 25.1μm long, 2.01μm broad, colpus margins sinuate.
Polar axis 24.7-27.9μm long, equatorial axis 19.7-26.6μm long. Exine reticulate or subreti-
culate, lumina nearly rounded, with verrocae visible under SEM.
According to the pollen morphology of Lespedeza and its allied genera, the division of
Lespedeza (s. lat.) into Lespedeza (S. str.), Campylotropis and Kummarowia by Schindler (1912)
is reasonable. The subdivision of Lespedeza (s. str.) into Sect. Macrolespedeza and Sect. Lespe-
deza by many botanists, and the treatment of Lespedeze juncea (L. f.) Pers. var. inschanica
Maxim. as an independent species (i.e. Lespedeza inschanics (Maxim). Schindl.) are also suppor-
ted by the pollen morphology shown in the present work. 相似文献
8.
半蒴苣苔属的研究(续) 总被引:1,自引:0,他引:1
李振宇 《中国科学院研究生院学报》1987,25(3):220-230
The genus Hemiboea is a curious genus of the tribe Didymocarpeae (Cyrtandroi-
deae), characterized by its peculiar pistil with one fertile carpel and its follicle-like capsule. This genus has not yet been thoroughly studied since its establishment by C. B. Clarke in 1888. In
the present paper, the taxonomic history is briefly reviewed; the external morphology, leaf his-
tology, pollen morphology and geographical distribution are discussed; a key to the 21 species
recognized by the author is provided; and the economic uses reported in various publications
are summarized.
I. Morphology
(1) Sclereids The foliar sclereids, occurring in this genus and defined by their forms,
fall into two types.
(A) Vermiform selereids This type of sclereids is noted in 15 species and may be clas-
sified into two groups according to their positions in leaf tissues. Those of the first group
are interspersed in the ground tissue around the vascular bundles of leaves and noted in 12
species, i.e.H. longisepala, H. cavaleriei, H. bicornuta, H. fangii, H. omeiensis, H. gracilis,
H. glandulosa, H. mollifolia, H. pingbianensis, H. parviflora, H. strigosa and H. gamosepala,
and those of the second group are dispersed in the mesophyll, occurring in H. subcapitata, H.
henryi and H. latisepala.
(B) Astrosclereids The sclereids of this type are discovered for the first time in Hemiboea,
dispersed in the mesophyll of a single species, i.e.H. lungzhouensis.
No foliar sclereids are found in the remaining 5 species, i.e.H. integra, H. flaccida, H.
longgangensis, H. subacaulis and H. follicularis.
The differences in forms and positions of the foliar sclereids and their absence or pre-
sence are of great help in understanding the relationship between the infrageneric taxa.
(2) Pollen grains The pollen grains of 19 species were examined with LM and SEM.
They are 3-colporate, subglobose or prolate, 20-38.8×22-28μm. The exine is 1.3-2μm
thick and the sculpture is foveolate (e.g.H. cavaleriei) to reticulate (e.g.H. omeiensis). In
Sect. Subcapitatae the pollen grains are subglobose or prolate, while those of Sect. Hemiboea are
prolate.
No pollen grains are observed in anthers of 13 speciemens of H. subacaulis var. subacaulis
and var. jiangxiensis.
(3) Seed-coat Under SEM the seed-coat exhibits considerable diversity in the genus, fur-
nishing useful characters for explaining the relationship between the two sections.
2. Geographical distribution The genus Hemiboea ranges from the eastern border of the
Xizang Plateau and Yunnan Plateau eastwards to Ryu Kyu Islands, and from the southern
slope of the Qinling Range southwards to northern Vietnam. The karst region of S. E. Yun-
nan and W. Guangxi is the centre of maximum variation of the genus and is probably its origin
centre, where the most primitive taxon exists, and where more species (13 species, i.e. 61.9 per
cent of the sum total) and more endemic species (8 species) are found than elsewhere.
3. Classification The genus consists of 21 species and 6 varieties which are classified into
2 sections. The Clarke's classification is accepted, but emended here as follows:
Sect. 1. Subcapitatae Clarke Sepals free or posterior ones connate. Muri of the seed-coat
laevigate or rugose; bottom of meshes flat, smooth or with few verrucae. Pollen grains subglo-
bose or prolate.
Sect. 2. Hemiboea Sepals connate. Muri of the seed-coat tuberculate or aliform-tuberculate;
bottom of meshes flat or concave, with dense verrucae. Pollen grains prolate.
Based on the analysis of external and internal morphological characters, the main evolu-
tionary trends in the genus are discussed and enumerated, and a hypothesis indicating the re-
lationships between the two sections is given. 相似文献
9.
李中明 《中国科学院研究生院学报》1983,21(2):153-160
The genus Palaeosmunda was established by R. E. Gould in 1970 based upon some
Late Permian Osmundaceous trunks with well-developed leaf gaps and rhomboidal
sclerotic ring within petiolar base seen in cross section. As he thinks that the latter
character is more important than the former, this genus could not be assigned to any
subfamily of Osmundaceae.
However, the leaf gap is one of the most important characters in the structure of the fern stem, so the author suggests that this genus should be assigned to subfamily
Osmundoideae and its diagnosis must be emended as follows:
The genus Palaeosmunda is represented by some rhizomes (or trunks), roots and
leaf bases of ferns which structurally are preserved, resembling Osmundacaulis but
which can’t be assigned to any group of this genus.
Stem containing an ectophloic dictyoxylic siphonostele; if tracheids present in
the pith, they being multiseriate scalariform pitted; pith or cortex sometimes contain-
ing groups of secretory cells or sclerenchyma; number of leaf traces seen in a tran-
sverse section of cortex more than 30; leaf traces adaxially curvature, rarely oblong-
shaped; petiolar bases with or without stipular expansion, containing a C-shaped
vascular strand; root diarch.
Type species——Palaeosmunda williamsii.
According to this diagnosis some primitive osmundaceous species with the leaf
gaps, which have already found in Upper Permian and Lower Triassic, could be assigned
to this genus. Two of them are P. williamsii Gould and P. playfordii Gould, and
Osmundacaulis beardmorensis, which was from Lower Triassic of Antarctica in 1978,
should be assigned to the genus Palaeosmunda.
In this paper two osmundaceous new species: P. primitiva and P. plenasioides were
found in the coal balls of Upper Permian age from Wangjiazhai of Shuicheng of
Guizhou Province, China.
P. primitiva is represented by two trunks; stem about 4 cm in diameter; stele
actophloic dictyoxylic siphonostele; pith cavity about 3—4 mm in diameter, contianing
parenchyma and tracheids; xylem cylinder thin, less than 10 tracheids in radial thick-
ness, dissected by leaf gaps. Inner cortex about 1.5 cm thick, mainly parenchymatous,
but sometimes containing a few sclerenchymatous; number of leaf traces seen in a
transverse section about 50—60; leaf traces departing at 35—45º,open C-shaped at
point of departure, gradually becoming shallow C-shaped or V-shaped in different
parts; protoxylem in base of leaf traces single, endarch; when leaf traces pass through
inner cortex, protoxylem biturcating. Petiole bases without stipular expansion, probablyloosely embracing the stem; xylem strand of potiole trace shallow C-shaped, surrounded by selerenchyma; sclerotic ring round, connected with single sclerenchyma mass in the concavity of the petiole trace. Root arising singly from leaf trace, diarch, with inner and outer cortex.
P. plenasioides is represented by a rhizome; stem more than 4 cm in diameter;
stele actophloic dictyoxylic siphonostele; xylem cylider with about 20 tracheids in
radial thickness, dissected by leaf gaps; xylem bundle U-, O-, or crosier- (i.e. query-)
shaped; pith and inner cortex parenchymatous, with many groups of secretory cells;
leaf trace C-shaped, its base containing two endarch protoxylem groups; root diareh,with inner and outer cortex, arising singly from leaf trace or its base. 相似文献
10.
王文采 《中国科学院研究生院学报》1980,18(3):266-282
1. Having analyzed the external morphology of the genus Microula, the author
has proposed a series of criteria as bases for the construction of a classification scheme
of this genus. The most important ones are as follows:
1) The normally developed stem is primitive, and the strongly abbreviated stem
more advanced.
2) The small inconspicuous bracts are more primitive than the large suborbicular
densely arranged ones, which almost entirely cover the flowers and the fruits.
3) Nutlets with small dorsal pit are more primitive than those with larger pit
on one hand or those without it on the other.
4) The dorsal pit with simple margin precedes that with double margins.
5) Nutlets with subbasal areola precede those with lateral or apical areola.
6) Nutlets without glochids precede those with glochids.
2. Basing upon these criteria the genus Microula may be divided into six sections.
The section Schistocaryum may be the primitive one, and the others may be evolved
from it respectively. The possible affinities between them are demonstrated in figure
no. two.
3. The genus Microula, containing 30 species, is mainly distributed in the
Chinghai-Tibetan plateau and the majority of its species concentrates in the eastern
border of the plateau, and of the 30 species 26—that is 90 percent—are endemic
to China, and the remaining 4 are distributed elsewhere in China, too, and extending
southward and westward to Bhutan, Sikkim, Nepal and Kashmir respectively. In the
region between Heishui, Province Szechuan, and Chinghai Lake there are 9 species,
which, curiously, represent all the six sections of Microula, hence this region seems to
be the center of maximum variation of this genus. M. ovalifolia whose nutlets have
small dorsal pit and subbasal areola may be considered the most primitive species.
Thus the author is of the opinion that the western part of province Szechuan, to
which M. ovalifolia is endemic, may probably be the center of origin of the genusMicroula. 相似文献
11.
赵继鼎 《中国科学院研究生院学报》1964,9(2):139-166
Parmelia is a genus of economical importance. According what was recorded,
Meyen & Flotow were the first foreigners to study Chinese lichens in 1843. Up to the
present time 74 species, 24 varieties and 11 forms have been described from China.
The majority of specimens reported in this paper were collected by many Chinese
botanists and collectors from 21 provinces from 1928--1962, while a few of them were
collected by Licent from 1916 to 1917 and by Poliansky in 1957.
The system of classification adopted here is that held by A. Zahlbruckner in 1926.
But in section Hypotrachyna, the two subsections-Myelochroa and Myeloleuca proposed
by Asahina are adopted and Parmelia xanthocarpa which has not been properly placed
before, is here referred to the subsection Myelochroa.
In the subgenus Hypogymnia the writer discovers that the length of spores of two
species are longer than 10μ, especially Parmelia macrospora reaches 17.5μ long. So
far as the writer knows, the upper limitation of the spore length recognized by many
lichenologists has been 10μ in this subgenus. The spore measurement of this subgenus
needs, therefore, to be revised in future.
In this paper 78 species, 14 varieties and 6 forms are presented. Among them, 5
species, 5 varieties and 1 forms are considered as new and two new combinations have
been made. Out of all these, 31 species, 6 varieties and 2 forms are first recorded from
China. All the materials cited are deposited in the Mycological Herbarium of Instituteof Microbiology, Academia Sinica, Peking. 相似文献
12.
李承森 《中国科学院研究生院学报》1982,20(3):331-342
A new psilophytic plant, Hsüa robusta, is found in the Xujiachong Formation
(Emsian) of the Lower Devonian from the Qüjing (= Kütsing) district of Yunnan,
China. This plant is tentatively referred to the Cooksoniaceae of Rhyniales.
Hsüa gen. nov.
Type species: Hsüa robusta (Li et Cai) C. S. Li.
Diagnosis: Plants erect and then creeping. Main axes dividing pseudomonopodial-
ly and bearing dichotomous lateral branches which somewhat differentiate into vegeta,
tire and fertile ones, with dichotomous root-like and rhizophore-like appendages. Spo-
rangia terminal, round to reniform or wide reniform, dehiscing along distal margin into
two equal halves. Spores homosporous, trilete. Stomata anomocytic. Protostele cen-
trarch.
Hsüia robusta (Li et Cai) C. S. Li, comb. nov.
Cooksonia zhanyiensis Li et Cai, Acta Geologica Sinica, 52 (1) 1978, p. 10, pl. II,
fig. 6.——Taeniocrada robusta Li et Cai,ib. p. 10, pl. II, fig. 7—14.
Diagnosis: Characters same as in generic diagnosis. Main axes 6—10 mm wide and
at least 24 cm long, with vascular strands 1.2—2.4 mm acr oss. Fertile branches 3—4
times equally or unequally dichotomous, 10—1.5 mm in width and up to 11 cm in length,
possessing a vascular bundle of 0.5 mm in its greatest diameter. Branches circinately
coiled in apical regions. Axial tubercles, root-like and rhizophore— like appendages aris-
ing from the main axes usually anterior to the lateral branches. Axial tubercle round
with a diameter of 2.2—2.4 mm, having a vascular bundle about l mm across. Root-
like branches 3 times bifurcate, 1—0.3 mm wide and up to 1.5 cm long, with a vascular
bundle about 0.1 mm across. Rhizophore-like appendages forked, 3—1.7 mm in width,
possessing a vascular bundle of 0.7 mm in its greatest diameter. Root-like protuberances
sometimes arising from rhilzophore-like branches. Epidermal cells of axes generally
elongate, measuring 60—290μby 25—60 μ. Stomata mainly fusiform, 90—110 μ long
and 50—60μ wide, consisting of a pair of guard cells enclosing a pore 6—15μ in length
and 1—3μ in width. Cuticle of guard cells quite thick. Stomatal density about 5 per
mm2. Sporangia 0.8—4.2 mm high, 1.0—8.2 mm across, usually having a dehiscent distal
border which measures 50—100μ broad. Demarcation between sporangium and its stalk
quite clear. Epidermal cells of basal part of sporangial walls elongate, about 100 μ long
and 30μ wide, but those of distal part isodiametrally polygonal, about 50μ in diame-
ter. Stomata, radially arranged scattering over sporangial walls, generally round about
50μ in diameter and 50 per sporangium. Spores round, 18—36μ (average 27μ) indiameter, and smooth. Tracheids of protoxylem about 10μ across; those of metaxylem
about 30μ across, with scalariform thickening.
This plant is similar to Renalia hueberi Gensel in general morphology, but differs
from the latter in possessing root-like and rhizophore-like branches.
The generic name is derived from Prof. Hsü Jen. This paper is a thesis for M. Sc. 相似文献
13.
【目的】 调查医学论文中成组t检验的P值错误,分析错误原因,并提出相应措施。【方法】 选取236种医学期刊,每种期刊选取1项成组t检验,核验其P值,应用χ2检验、Mantel-Haenszel法、二项式logistic回归分析P值错误。【结果】 236项成组t检验中,50项存在P值错误。单因素分析结果显示,核心期刊与非核心期刊相比,P值错误发生率差异具有统计学意义(χ2=4.871,P=0.027);给出具体P值组与未给出具体P值组相比,P值错误发生率差异具有统计学意义(χ2=15.440,P<0.0001)。将是否给出具体P值作为混杂因素,比较核心期刊与非核心期刊P值错误发生率,差异无统计学意义(χ2=2.703,P=0.100)。多因素分析结果显示,是否方差齐(OR值为0.470,95%CI为0.230~0.961)、是否给出具体P值(OR值为5.459,95%CI为2.311~12.895)具有统计学意义。【结论】 医学论文成组t检验P值错误较多。为及时发现P值错误,期刊编辑应当重视对统计学方法应用条件的审查,要求作者给出统计描述以及统计推断的具体结果,能够利用简单易学的统计学软件核实P值。 相似文献
14.
论胡桃科植物的地理分布 总被引:1,自引:0,他引:1
路安民 《中国科学院研究生院学报》1982,20(3):257-274
The present paper aims to discuss the geog raphical distribution of the Juglandaceae
on the basis of unity of the phylogeny and the process of dispersal in the plants.
The paper is divided into the following three parts:
1. The systematic positions and the distribution patterns of nine living genera in
the family Juglandaceae (namely, Engelhardia, Oreomunnea, Alfaroa, Pterocarya, Cyclo-
carya, Juglans, Carya, Annamocarya and Platycarya) are briefly discussed. The evolu-
tional relationships between the different genera of the Juglandaceae are elucidated. The
fossil distribution and the geological date of the plant groups are reviewed. Through
the analysis for the geographical distribution of the Juglandaceous genera, the distribu-
tion patterns may be divided as follows:
A. The tropical distribution pattern
a. The genera of tropical Asia distribution: Engelhardia, Annamocarya.
b. The genera of tropical Central America distribution: Oreomunnea, Alfaroa.
B. The temperate distribution pattern
c. The genus of disjunct distribution between Western Asia and Eastern Asia:
Pterocarya.
d. The genus of disjunct distribution between Eurasia and America: Juglans.
e. The genus of disjunct distribution between Eastern Asia and North America:
Carya.
f. The genera whose distribution is confined to Eastern Asia: Cyclocarya, Platy-
carya.
2. The distribution of species
According to Takhtajan’s view point of phytochoria, the number of species in every
region are counted. It has shown clearily that the Eastern Asian Region and the Coti-
nental South-east Asian Region are most abundant in number of genera and species. Of
the 71 living species, 53 are regional endemic elements, namely 74.6% of the total species.
The author is of the opinion that most endemic species in Eurasia are of old endemic
nature and in America of new endimic nature. There are now 7 genera and 28 species
in China, whose south-western and central parts are most abundant in species, with Pro-
vince Yunnan being richest in genera and species.
3. Discussions of the distribution patterns of the Juglandaceae
A. The centre of floristic region
B. The centre of floristic regions is determined by the following two principles: a.
A large number of species concentrate in a district, namely the centre of the majority;
b. Species of a district can reflect the main stages of the systematic evolution of the
Juglandaceae, namely the centre of diversity. It has shown clearly that the southern
part of Eastern Asian region and the northern part of Continental South-east Asian
Region (i.c. Southern China and Northern Indo-China) are the main distribution centre
of the Juglandaceae, while the southern part of Sonora Region and Caribbean Region
(i.c. South-western U.S.A., Mexico and Central America) are the secondary distribution
centre.
As far as fossil records goes, it has shown that in Tertiary period the Juglanda-
ceae were widely distributed in northern Eurasia and North America, growing not only
in Europe and the Caucasus but also as far as in Greenland and Alaska. It may be
considered that the Juglandaceae might be originated from Laurasia. According to
the analysis of distribution pattern for living primitive genus, for example, Engelhar-
dia, South-western China and Northern Indo-China may be the birthplace of the most
primitive Juglandaceous plants. It also can be seen that the primitive genera and the
primitive sections of every genus in the Juglandaceae have mostly distributed in the
tropics or subtropics. At the same time, according to the analysis of morphological cha-
racters, such as naked buds in the primitive taxa of this family, it is considered that
this character has relationship with the living conditions of their ancestors. All the
evidence seems to show that the Juglandaceae are of forest origin in the tropical moun-
tains having seasonal drying period.
B. The time of the origin
The geological times of fossil records are analyzed. It is concluded that the origin
of the Juglandaceae dates back at least as early as the Cretaceous period.
C. The routes of despersal
After the emergence of the Juglandaceous plant on earth, it had first developed and
dispersed in Southern China and Indo-China. Under conditions of the stable tempera-
ture and humidity in North Hemisphere during the period of its origin and development,
the Juglandaceous plants had rapidly developed and distributed in Eurasia and dis-
persed to North America by two routes: Europe-Greenland-North America route and
Asia-Bering Land-bridge-North America route. From Central America it later reached
South America.
D. The formaation of the modern distribution pattern and reasons for this forma-
tion.
According to the fossil records, the formation of two disjunct areas was not due to
the origin of synchronous development, nor to the parallel evolution in the two con-
tinents of Eurasia and America, nor can it be interpreted as due to result of transmis-
sive function. The modern distribution pattern has developed as a result of the tectonic
movement and of the climatic change after the Tertiary period. Because of the con-
tinental drift, the Eurasian Continent was separated from the North American Conti-
nent, it had formed a disjunction between Eurasia and North America. Especially, under
the glaciation during the Late Tertiary and Quaternary Periods, the continents in Eu-
rasia and North America were covered by ice sheet with the exception of “plant refuges”, most plants in the area were destroyed, but the southern part of Eastern Asia
remained practically intact and most of the plants including the Juglandaceae were
preserved from destruction by ice and thence became a main centre of survival in the
North Hemisphere, likewise, there is another centre of survival in the same latitude in
North America and Central America.
E. Finally, the probable evolutionary relationships of the genera of the Juglanda-ceae is presented by the dendrogram in the text. 相似文献
15.
秦仁昌 《中国科学院研究生院学报》1964,9(1):99-99
The fern genus Diplaziopsis C. Chr. of Index Filicum has long been considered as
a monotypic one, with the sole species, D. javanica (B1.) C. Chr. from tropical Asia. In
1906, H. Christ described a second species, Allantodia cavaleriana Christ (=D. cavale-
riana C. Chr.) from Kweichow, West China, but this was since not fully recognized by
fern students in general, being often considered as a variety of the first species. This
is certainly a mistake, as is shown by ample herbarium specimens today. In the recent
work on the genus, the writer has found among the herbarium material two additional
new species from China, thus bringing the genus up to four species in Asia, mainly from
China, where, as it is, the genus has its center of development from the long past.
Phylogenetically, Diplaziopsis C. Chr. represents one of the offshoots from the great
stock of diplazioid ferns, of which the genus Diplazium Sw. constitutes the main body
of the group and from which our genus differs chiefly in its leaves of a thin texture with
reticulated venation, but not so much in its type of indusium as it has generally been
emphasized by most botanists in the past, for, as it is, the type of indusium in Di-
plaziopsis also prevails in many species of Diplazium, for which C. B. Clarke (Trans.
Linn. Soc. ser. 2, Bot. I:495, 1880) created, but really superfluously, a subgenus Pseudal-
lantodia, about which the writer will dwell in another paper in the near future. Suffice
it to say here that the indusium in Diplaziopsis as revealed by the species treated here
is, indeed, typical of diplazioid ferns, only often, as it happens, with its adaxial edge
pressed so tight under the expanding sorus that it is unable to open freely along its upper
free edge and, as a result, its thin vaulted back bursts open from the pressure of the ex-
panding sorus underneath.
As a result of the present study, following four species of the genus have been re-
cognized.
Diplaziopsis javanica (B1.) C. Chr. Ind. Fil. (1905) 227.
Wide spread in tropical Asia, northwardly to Bakbo and the southern part of Yun-
nan, China.
D. cavaleriana (Christ) C. Chr. Ind. Fil. Suppl. I (1913) 25.
Ranges from West China through northern part of Fukien of East China to Japan.
D. intermedia Ching, sp. nov.
Endemic in West China: Mt. Omei, Szechuan, and Kweichow.
D. hainanensis Ching, sp. nov.
In conclusion, it may be pointed out that with the modern plant taxonomy pursued
in a more efficient manner than in the past, and especially by the introduction of the
cytotaxonomic methods, the so-called “monotypic genera”, as conceived by the orthodox
systematists, will continue to prove, to a great extent, to be lack of enough scientific
ground. The fact that the “monotypic genus” of Diplaziopsis C. Chr. is now found to
be a genus of four well-defined species is once again an instance to illustrate the pointat issue. 相似文献
16.
【目的】 分析《湖泊科学》近10年的自引行为变化规律,剖析产生原因,思考期刊非正常自引现象,引导期刊自引的客观认识,更好地办好学术期刊。【方法】 根据《中国科技期刊引证报告(核心版)》的数据以及《湖泊科学》2006—2015年载文的参考文献,得到《湖泊科学》近10年的自引率(RSC),总被引频次(FTC),总自引频次(FSC),对影响因子(IF)有贡献的总被引频次(FTCIF)、自引频次(FSCIF),自引率(RSCIF),载文数量,平均引文数量以及IF等评价指标,分析各指标的变化趋势以及相互之间的关系。【结果】 在无人为操控的前提下,《湖泊科学》近10年RSC变化较小,FTC、FSC、FSCIF以及载文数量均有升高趋势,RSCIF略高于RSC,但是自引对IF无显著影响。【结论】 RSC与学科大小和研究范围有关。增加科研投入、提升期刊内容质量、应用数字化手段以及加大推广力度等因素导致了FTC、FSC和FSCIF等指标升高。期刊出现RSC过高或突然大幅度升高、FSCIF与IF有很强的相关性、RSCIF大大高于RSC等现象时,很可能是人为操控所致。中国科技期刊编辑只有自律自强,才能够使得中国科技期刊的学术质量真正获得国内科技工作者的认同并且在国际舞台上占有一席之地。 相似文献
17.
18.
引洮供水工程是以九甸峡水利枢纽为龙头,为改善甘肃省中部地区极度缺水现状而实施的跨流域调水工程。2010年和2020年水平年洮河下游总需水量分别为47.26×108m3和47.74×108m3,引洮需水量分别为2.14×108m3和6.04×108m3。在分析九甸峡梯级水库群特点的基础上,以尽可能满足引洮水量、洮河下游生产生活需水,以及下游生态用水为目标,建立了该系统的模拟调度模型,并确定了系统结构和调度原则。结合引洮工程实际情况,设定了三种方案,分别考虑2010年一期工程、2020年一期工程和2020年二期工程。通过长系列模拟计算,得出了各方案的水资源利用情况,模拟计算表明,不同水平年多年平均引洮水量和洮河下游经济社会、生态环境用水均可保证,但冲沙用水不能满足,三个方案缺水量分别为0.95×108m3、0.98×108m3和2.31×108m3;典型年计算结果表明,只有在来水较丰时,才能同时满足洮河下游需水量和引洮水量的需求,典型枯水年和平水年分别缺水11.51×108m3和3.13×108m3。 相似文献
19.
The fossils here described were collected from the Lai Yuan, Hebei Province in
north China. Well-preserved plant parts are cones of Pinus, identified as Pinus pro-
totabulaeformis sp. nov. The species is different from other taxa of Pinus by larger
cones and scales. The size of the cone is a reliable diagnostic character in the group:
The large cone and scale indicate rather an arid climate in Summer in the region
where the fossils are discovered.
The age of bearing-beds is considered Upper Eocene-Lower Oligocene.
Diagnosis: Cones ovate in general outline, 8.5 cm long, 4.5 cm in diameter. Seed
scales oblong, 2—2.5 cm long, 0.8—1.1 cm wide. Apophysis obviously fattened andthickned, convex, compressed rhomboid, rostrate at the apical part of seed-bract. 相似文献
20.
路安民 《中国科学院研究生院学报》1984,22(6):497-508
The present paper aims at introducting Dahlgren’s system of classification of the angiosperms. Phenetic and phylogenetic classifications are discussed. The basic principles and methods used by Dahlgren are explained. Dahlgren’s opinions on some important problems, such as the origin of angiosperms, the flowers of primitive angiosperms, the relation between the dicotyledons and monocotyledons, the origin of the monocotyledons, the treatment of the “Amentiferae” and of the orders of the “Sympetalae”, are all expressed. A brief comparison between Dahlgren’s system and three other current systems, viz. those of Takhtajan, Cronquist and Thorne is also given. 相似文献