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1.
This paper deals with the taxa of tribe Arundinarieae Steud. subtribe Pleiobalastinae Keng and Keng f. which comprised three genera (Pseudosasa Makino, Pleioblastus Nakai and Brachystachyum Keng) when it was established in 1957. With the analysis of morphological characters and geographical distribution, a number of revisions connected with the taxon are made as follows:
(1) Genus Brachystachyum Keng is transferred to the tribe Shibataeeae Nakai ac-
cording to its false inflorescence.
(2) Genus Pseudosasa Makino is transferred to subtribe Sasinae Keng f. according to our study on the numerical taxonomic method.
(3) Some species of Pleioblastus Nakai established by Keng and Keng f. should be
revised. Pleioblastus actinotrichus (Merr. and Chun) Keng f. should be Ampelocalamus actinotrichus (Merr. and Chun) S. L. Chen, T. H. Wen and G. Y. Sheng in subtribe Tham-
nocalaminae Keng f.; Pleioblastus dolichanthus (Keng) Keng f. is the synonym of Sinobam-
busa tootsik (Sieb.) Makino, belonging to tribe Shibataeeae Nakai. The rest species remain in this genus. Since the genus Pleioblastus is related to genus Arundinaria Michaux., subtribe Pleioblastus Keng and Keng f. does not seem to have a reason to be retained as a subtribe in tribe Arundinarieae Steud., according to the newest Code (1978). A part of it should be a synonym of subtribe Arundinariinae and we may cite it as follows: Subtribe Arundinariinae——Subtribe Pleioblastinae Keng and Keng f. pro parte, syn. nov. The other parts of it should be transferred to other subtribes or tribes.
In addition, one new variety in Branchystachyum, two new species, one new variety in Pseudosasa and six new species, three new varieties in Pleioblastus, are described in this paper. 相似文献
2.
The present paper deals with the following three aspects:
1. It attempts to discuss the problems on primitive forms of the family Araliaceae.
The genus Tupidanthus Hook. f. & Thoms. was considered by H. Harms (1894) and H.
L. Li (1942) as primitive, whilst another genus Plerandra A. Gray was regarded as
primitive by R. H. Eyde & C. C. Tseng in 1971. Having made a detailed comparison of
the taxonomical characters of these two genera, the present authors believe that both
genera are not the most primitive in the Araliaceae. Their affinit yis not close enough
and they possibly evolved in parallel lines from a common ancestor which is so far un-
known yet.
2. By studying the systems of the past, the present authors believe that none of them is entirely satisfactory. Bentham (1867) recognized five ‘series’ (in fact, equival-
ent to ‘tribe’ with the ending-eae of names) based on the petaline arrangement in the
bud, the numbers of stamen and the types of endospem. This is a plausible funda-
mental treatment for the Araliaceae, but choosing the endosperm as a criteria in dividing
tribe is artifical. As we know today, both ruminate and uniform endosperm are usually
presente in the same genus. Seemann’s system (1868) divided the Hederaceae (excl.
Trib. Aralieae) into five tribes, in addition to the locules of ovary. The criteria are
essentially the same as Bentham’s. The system of Hams (1894) divided the family into
three tribes. Two tribes, Aralieae and Mackinlayeae, of Bentham are retained, but
other groups were combined in the Trib. Schefflereae. However, Harms did not retain
one of those three oldest legitimate names which had named by Bentham, that is con-
trary to the law of priority in the International Code of Botanical Nomenelature. Hut-
chinson (1967) adopted seven tribes for the family. The criteria essentially follow those
of Bentham, but the inflorescence is overstressed. The inflorescence is an artifical taxono-
mical character in dividing tribes, because of some dioecious plants, such as Meryta sin-
clairii (Hook. f.) Seem., have two types of inflorescence in male and female plants. Ac-
cording to Hutchinson’s arrangement, the male and female plants would be put in se-
parate tribes.
3. The present authors are of the opinion that in the study of a natural classi-
fication of plant groups emphasis should be laid not only on the characters of the repro-
ductive organs, but on those of vegetative organs as well. The present revised system is
based principally upon the characters of both flowers and leaves of the five tribes as
follows:
Trib. 1. Plerandreae Benth. emend. Hoo & Tseng
Trib. 2. Tetraplasandreae Hoo & Tseng
Trib. 3. Mackinlayeae Benth.
Trib. 4. Aralieae Benth.
Trib. 5. Panaceae Benth. emend. Hoo & Tseng 相似文献
3.
1) The Compositae in Tibet so far known comprise 508 species and 88 genera,
which nearly amounts to one fourth of the total number of genera and one third of the
total number of species of Compositae in all China, if the number of 2290 species and 220
genera have respectively been counted in all China. In Tibet there are all tribes of Com-
positae known in China, and surprisingly, the large tribes in Tibetan Compositae are
also large ones in all China and the small tribes in Tibet are also small ones in all China.
Generally speaking, the large genera in Tibet are also large ones in all China and the
small genera in Tibet are likewise small ones in all China. In this sense it is reasonable to
say that the Compositae flora of Tibet is an epitome of the Compositae flora of all China.
In the Compositae flora of Tibet, there are only 5 large genera each containing 30
species or more. They are Aster, Artemisia, Senecio, Saussurea and Cremanthodium. And
5 genera each containing 10—29 species. They are Erigeron, Anaphalis, Leontopodium,
Ajania, Ligularia and Taraxacum. In addition, there are 77 small genera, namely 87%
of the total of Compositae genera in Tibet, each comprising 1—9 species, such as Aja-niopsis, Cavea and Vernonia, etc.
2) The constituents of Compositae flora in Tibet is very closely related to those of
Sichuan-Yunnan provinces with 59 genera and 250 species in common. Such a situation
is evidently brought about by the geographycal proximity in which the Hengtuang Shan
Range links southeastern and eastern Tibet with northern and northwestern Sichuan-
Ynnnan. With India the Tibetan Compositae have 59 genera and 132 species in common,
also showing close floristic relationships between the two regions. Apparently the floris-
tic exchange of Compositae between Tibet and India is realized by way of the mountain
range of the Himalayas. The mountain range of the Himalayas, including the parallel
ranges, plays a important role as a bridge hereby some members of the Compositae of
western or northern Central Asia and of the northern Africa or of western Asia have
migrated eastwards or southeastwards as far as the southern part of Fibet and northern
part of India, or hereby some Compositae plants of eastern and southeastern Asia or
Asia Media have migrated northwestwards as the northern part of Central Asia.
Some of the species and genera in common to both Tibet and Sinjiang indicate that
this weak floristical relationship between these regions is principally realized through two
migration routes: one migration route is by way of the Himalayas including the parallel
ranges to Pamir Plataeu and Tien Shan, or vice versa. The other migration route is by
way of northern Sinjiang to Mongolia, eastern Inner Mongolia, southwards to Gansu,
Qinghai (or western Sichuan), eastern Tibet up to the Himalayas, or vice versa.
However, Tibet is not entirely situated at a migration crossroad of the floral ele-
ments. An ample amount of the data shows that Compositae flora have a particular
capability of development in Tibet. of the total number of species of Tibetan Com-
positae, 102 species and 1 genus (Ajaniopsis Shih) are endemic. Besides, 8 genera are re-
gional endemics with their range extending to its neighbourhood. The higher percentage
of endemics at specific level than at generic in Tibetan Compositae may be a result of
active speciation in response to the new enviromental conditions created by the uplifting
of the Himalayas. The flora in Tibetan Plateau as a whole appears to be of a younger
age.
3) The uprising of the Himalayas and of the Tibetan Plateau accompanied by the
ultraviolet ray radiation, the microthermal climate and the high wind pressure has, no
doubt, played a profound influence upon the speciation of the native elements of Tibetan
Compositae. The recent speciation is the main trend in the development of the Com-positae flora native in Tibet in the wake of upheaval of the plateau. 相似文献
4.
木兰科分类系统的初步研究 总被引：10，自引：0，他引：10
刘玉壶 《中国科学院研究生院学报》1984,22(2):89-109
A new system of classification of Magnoliaceae proposed. This paper deals mainly with taxonomy and phytogeography of the family Magnoliaceae on the basis of external morphology, wood anatomy and palynology. Different authors have had different ideas about the delimitation of genera of this family, their controversy being carried on through more than one hundred years (Table I). Since I have been engaged
in the work of the Flora Reipublicae Popularis Sinicae, I have accumulated a considerable amount of information and material and have investigated the living plants at their natural localities, which enable me to find out the evolutionary tendencies and primitive morphological characters of various genera of the family. According to the evolutionary tendencies of the characters and the geographical distribution of this family I propose a
new system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law (1979), two tribes, Magnolieae and Michelieae Law, four subtribes, Manglietiinae Law, Magnoliinae, Elmerrilliinae Law and Micheliinae, and fifteen genera (Fig. 1 ), a system which is different from those by J. D. Dandy (1964-1974) and the other authors.
The recent distribution and possible survival centre of Magnoliaceae. The members of Magnoliaceae are distributed chiefly in temperate and tropical zones of the Northern Hemisphere, ——Southeast Asia and southeast North America, but a few genera and species also occur in the Malay Archipelago and Brazil of the Southern Hemisphere. Forty species of 4 genera occur in America, among which one genus (Dugendiodendron) is endemic to the continent, while about 200 species of 14 genera occur in Southeast Asia, of which 12 genera are endemic. In China there are about 110 species of 11 genera which mostly occur in Guangxi, Guangdong and Yunnan; 58 species and more than 9 genera occur in the mountainous districts of Yunnan. Moreover, one genus
(Manglietiastrum Law, 1979) and 19 species are endemic to this region. The family in discussion is much limited to or interruptedly distributed in the mountainous regions of Guangxi, Guangdong and Yunnan. The regions are found to have a great abundance of species, and the members of the relatively primitive taxa are also much more there than in the other regions of the world.
The major genera, Manglietia, Magnolia and Michelia, possess 160 out of a total of 240 species in the whole family. Talauma has 40 species, while the other eleven genera each contain only 2 to 7 species, even with one monotypic genus. These three major genera are sufficient for indicating the evolutionary tendency and geographical distribution of Magnoliaceae. It is worthwhile discussing their morphological characters and
distributional patterns as follows:
The members of Manglietia are all evergreen trees, with flowers terminal, anthers dehiscing introrsely, filaments very short and flat, ovules 4 or more per carpel. This is considered as the most primitive genus in subtribe Manglietiinae. Eighteen out of a total of 35 species of the genus are distributed in the western, southwest to southeast Yunnan. Very primitive species, such as Manglietia hookeri, M. insignis and M. mega-
phylla, M. grandis, also occur in this region. They are distributed from Yunnan eastwards to Zhejiang and Fujian through central China, south China, with only one species (Manglietia microtricha) of the genus westwards to Xizang. There are several species distributing southwards from northeast India to the Malay Archipelago (Fig. 7).
The members of Magnolia are evergreen and deciduous trees or shrubs, with flowers terminal, anthers dehiscing introrsely or laterally, ovules 2 per carpel, stipule adnate to the petiole. The genus Magnolia is the most primitive in the subtribe Magnoliinae and is the largest genus of the family Magnoliaceae. Its deciduous species are distributed from Yunnan north-eastwards to Korea and Japan (Kurile N. 46’) through Central
China, North China and westwards to Burma, the eastern Himalayas and northeast
India. The evergreen species are distributed from northeast Yunnan (China) to the
Malay Archipelago. In China there are 23 species, of which 15 seem to be very primi-
tive, e.g. Magnolia henryi, M. delavayi, M. officinalis and M. rostrata, which occur in
Guangxi, Guangdong and Yunnan.
The members of Michelia are evergreen trees or shrubs, with flowers axillary, an-
thers dehiscing laterally or sublaterally, gynoecium stipitate, carpels numerous or few.
Michelia is considered to be the most primitive in the subtribe Micheliinae, and is to
the second largest genus of the family. About 23 out of a total of 50 species of this
genus are very primitive, e.g. Michelia sphaerantha, M. lacei, M. champaca, and M.
flavidiflora, which occur in Guangdong, Guangxi and Yunnan (the distributional center
of the family under discussion) and extend eastwards to Taiwan of China, southern
Japan through central China, southwards to the Malay Archipelago through Indo-China.
westwards to Xizang of China, and south-westwards to India and Sri Lanka (Fig. 7).
The members of Magnoliaceae are concentrated in Guangxi, Guangdong and Yunnan
and radiate from there. The farther away from the centre, the less members we are
able to find, but the more advanced they are in morphology. In this old geographical
centre there are more primitive species, more endemics and more monotypic genera.
Thus it is reasonable to assume that the region of Guangxi, Guangdong and Yunnan,
China, is not only the centre of recent distribution, but also the chief survival centreof Magnoliaceae in the world. 相似文献
5.
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
6.
三种数值方法在几种六道木分类中的应用 总被引：1，自引：0，他引：1
In the last 10—20 years there has bee n increasing awareness of the problem con-
cerning the aims and practices of taxonomy. In particular, there has been growing
interest in the development of numerical methods in biological taxonomy as an aid to
making systematics a quantitative science, a step which comes in time to almost every
scientific discipline.
Numerical taxonomy is the evaluation by numerical methods of the affinity or
similarity between taxonomic units and the employment of these affinities in erecting
a hierarchic order of taxa. The present rapid development of these ideas is presuma-
bly a result of the development of computer techniques.
Numerical taxonomic approach has been applied to the studies of entomology and
microbiology in China to some extent since 1975. But so far it hasn’t been commonly
used in botany. The present report is a preliminary study on 9 spp. of the genus
Abelia. A set of binary data with 54 characters is used for computing association
coefficient; and a set of quantitative data with 47 characters for distance coefficient
and correlation coefficient. For the mathematical models were chosen the non-metric
simple matching association coefficient, the geometrical distance of Riemannian space
and correlation coefficient. Computational procedures are stepwise presented in detail
and computer programmes are written in the background of Algol-60 language. Cluster analysis is compared with simple linkage, average linkage and multi-correlation.
The results of DC and CC for 9 spp. of Abelia agree closely with the traditional
taxonomy, because the data we collected mainly come from morphological characters.
It would seem that the results of quantita tive data are more appropriate for seed
plants. It is, therefore, postulated that our programes are complementary and very
useful to a wide range of classification entities, such as microbes, animals and plants
in present situation in China.
In conclusion, a comparison between the conventional taxonomy and numerical
taxonomy has been made, and a brief discussion of three problems, i.e. the monothetic
versus polythetic, divisive versus agglomerative, weighting versus unweighting.
相似文献
7.
中国种子植物特有属的数量分析 总被引：3，自引：0，他引：3
王荷生 《中国科学院研究生院学报》1985,23(4):241-258
Chinese flora with many endemic elements is highly important in the world’s
flora. According to recent statistics there are about 196 genera of spermatophytes, be-
ing 6.5% of total Chinese genera. These endemic genera comprising 377 species belong
to 68 families, among which the Gesneriaceae (28 genera), Umbelliferae (13), Compo-
sitae (13), Orchidaceae (12) and Labiatae (10) are predominant. The tropical type
containing 24 families and 80 genera is dominant. After it follows the temperate type
with 23 families and 50 genera. There are also 4 families endemic to China, i.e. Gin-
kgoaceae, Bretschneideraceae, Eucommiaceae and Davidiaceae. It shows that genera
endemic to China are obviously related to the tropical and temperate flora in essence.
The endemic monotypic genera (139) and endemic obligotypic genera (48) combin-
ed make up more than 95% of the total number of genera endemic to China. Phylo-
genetically more than half of them are ancient or primitive. The life forms of all ende-
mic genera are also diverse. Herbs, especially perennial herbs, prevail with the propor-
tion of about 62%, and trees and shrubs are the next, with 33%, and the rest are lianas.
Based upon the calculated number of genera endemic to China in each province and
the similarity coefficents between any two provinces, some conclusions may be drawn
as follows:
Yunnan and Sichuan Provinces combined are the distribution centre of genera en-
demic to China and may be their original or differentiation area, because numerous
endemic genera, including various groups, exist in these two provinces. The second is
Guizhou where there are 62 endemic genera. Others form a declining order, south
China, central China and east China. But towards the north China endemic genera de-
crease gradually, and the Qinling Range is an important distributional limit.
The largest simitarity coefficient, over 50%, appears between Shaanxi and Gansu
probably because of the Qinling Range linking these two provinces. But between any
other two provinces it is less than 30% and it is generaly larger between two south pro-
vinces than between two north provinces.
These characteristics mentioned above are correlated with topography and climate,
and they may be resulted from the diversification in geography and climatic influence
for a long time. 相似文献
8.
The classical and numerical taxonomy, palynology and the geographical dis-
tribution of the Genus Schizopepon are dealt with in the present paper. Having comme-
nted on various opinions regarding the systematic position of the genus, the present au-
thors consider that C. Jeffrey’s treatment of Schizopepon as a new and monogeneric tri-
be, Schizopeponeae, should be supported.
The gross morphological characters in the genus are assessed from the taxonomic
point of view. Some characters, such as stamens with an elongated connective or not,
different insertions of ovules and various forms of ovaries and fruits, may be used for
distinguishing subgenera.
The pollen grains of all the species were observed under light microscope (LM) and
scanning electron microscope (SEM). The results show that a strong differentiation
has taken place in the pollen of the genus, and in consequence it may be regarded as an
important basis for dividing subgenera and species. Especially it should be pointed out
that degrees of development of colpi and positions of ora are positively correlated with
the external characters used for distinguishing subgenera.
According to the morphological and palynological characters, the genus Schizopepon
may be divided into three subgenera and eight species: 1. Subgenus Schizopepon: 5 spe-
cies, S. bryoniaefolius Maxim., S. monoicus A. M. Lu et Z. Y. Zhang, S. dioicus Cogn.,
S. longipes Gagnep. and S. macranthus Hand.-Mazz.; 2. Subgenus Rhynchocarpos A. M.
Lu et Z. Y. Zhang: 1 species, S. bomiensis A. M. Lu et Z. Y. Zhang; 3. Subgenus Neoschi-
zopepon A. M. Lu et Z. Y. Zhang: 2 species, S. bicirrhosus (C. B. Clarke) C. Jeffrey
and S. xizangensis A. M. Lu et Z. Y. Zhang.
The 8 OTU’s including all the species of this genus and 31 characters, of which 16 are morphological characters and 15 palynological characters, were used in the numerical taxonomic treatment. After standardization of characters, the correlation and distance matrices were computed. The correlation matrices are made to test the various clustering methods. At last, the UPGMA clustering method was selected and its result
is shown in the form of phenogram. The result of numerical analysis is similar to that of the classical classification.
Schizopepon Maxim. is a genus of East Asia-Himalayan distribution. China has all 8 species and 2 varieties, of which 6 species are endemic. Based on the statistics of spedies number, the distribution centre of the genus is considered to be in the Hengduan Mountains (Yangtze-Mekong-Salwin water divides) and the adjacent areas of the southwest China. 相似文献
9.
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
10.
We have described a new genus Taihangia, collected from, the south part of Taihang
Mountain in northern China. At the same time, comparative studies on Taihangia with its
related genera have been made in various fields including external morphology, anatomy
of carpels, chromosome and pollen morphology by light, scanning and transmission electron microscope. In addition, isoperoxidases of two varietier were analysed by means of polya-crylamide gel slab electrophoresis. The preliminary results are as follows:
Morphology: The genus Taihangia is perennial and has simple leaves, occasionally
with 1—2 very small reduced lobes on the upper part of petiole; flowers white, andromo-
noecious and androdioecious, terminal, single or rarely 2 on a leafless scape; calyx and cpicalyx with 5 segments; petals 5; stamens numerous; pistils numerous, with pubescent styles, spirally inserted on the receptacle in bisexual flowers, but with less number of abortive and glabrous pistils in male flowers.
In comparison with the related genera such as Dryas, Geum, Coluria and Waldsteinia,
the new genus has unisexual flowers and always herbaceous habit indicating its advanced
feature but the genus has a primitive style with thin and short hairs as compared with the genus Dryas which has long, pinnately haired styles, a character greatly facilitamg anemo-choric dissemination. The styles of Taihangia are slender and differ from those of the ge-nus Geum which are articulate, with a persistent hooked rostrum, thus adapting to epizo-ochoric dissemination to a higher degree.
The anatomy of carpels shows the baral position of ovules in the genus Taihangia like those in other related genera such as Dryas, Geum, Acomastylis, Coluria and Waldsteinia. This suggests that the new genus and its related ones are in a common evolutionary line as compared with the other tribes which have a pendulous ovule and represent a separate evolutionary line in Rosaceae. Dorsal and ventral bundles in carpels through sections are free at the base. Neither fusion, nor reduction of dorsals and vertrals. are observed. This shows that the genus Taihangia is rather primitive.
Somatic chromosome: All the living plants, collected from both Honan and Hopei
Provinces were examined. The results show that in these plants the chromosome number
is 2n= 14, and thus the basic number of chromosome is x=7. Such a diploid genus is first
found in both anemochoric and epizoochoric genera. Therefore, in this respect Taihangia is primitive as compared with herbaceous polyploid genus Geum and related ones.
Pollen: The stereostructure shown by scanning electron microscope reveals that the pollen grains of the genus Taihangia are ellipsoid and 3-colporate. There are two types of exine sculpture. One is rather shortly striate and it seems rugulate over the pollen surface; the other is long-striate. The genus Dryas differs in having only short and thick striae over the surface. The genus is similar to the genera Geum, Coluria and Waldsteinia in colpustype, but differs from them in that they all have long, parallel striae which are distributed along the meridional line.
In addition, under transmission electron microscope, the exine in the Taihangia and related genera Acomastylis, Geum, Coluria, Waldsteinia and Dryas has been shown to be typically differentiated into two distinct layers, nexine and sexine. The nexine, weakly statined, appears to consist of endoxine with no foot-layer, in which the columellae are fused, and which is thicker beneath the apertures. The sexine is 2-layered, consisting of columellae and tectum. Three patterns of tectum can be distinguished in the tribe Dryadeae: the first, in the genera Taihangia, Acomastylis, Geum, Coluria and Waldsteinia, is tectate-imperforate, with the sculpturing elements both acute and obtuse at the top and broad at the base; the second, in the genus Dryas, is semitectate, with the sculpturing elements shown in ultrathin sections rod-like and broader at the top than at the base or as broad at the top as at the base, and the third, tectate-perforate, with the sculpturing elements different in size. From the above results, the herbaceous groups and woody ones have palynologically evolved in two distinct directions, and the genus Taihangia is related to other herbaceous genera such as Acomastylis, Geum, Coluria and Waldsteinia, as shown in the electron microphotographs of ultrathin sections. The genus Taihangia, however, is different from related herbaceous genera in that the pollen of Taihangia is dimorphic, i.e. in addition to the above pattern of pollen another one of the exine in Taihangia is rugulate, with the sculpturing elements shown in the ultrathin sections being obtuse or emarginate and nearly as broad at the top as at the base.
The interesting results obtained from the comparative analysis of morphology, ana-
tomy of carpels, chromosome countings, microscopic and submicrosocopic structures of pollen may enable us to evaluate the systematic position of Taihangia and to throw a new light on evolution of the tribe Dryadeae. It is well known that the modes of dissemination of rosaceous fruits play an important role in the expansion and evolution of the family. The follicle is the most primitive and the plants with follicles, like the Spiraeoideae, are mostly woody and mesic, while the achene, drupe and pyrenarium are derived. In Rosoideae having a achene is a common feature. Particularly in the tribe Dryadeae, which is distinguished from the other related tribes by having orthotropous ovules, the methods of dissemination of fruits have developed in three distinct specialized directions: anemochory with long, plumose styles (e.g. Dryas), formicochory or dispersed by ants or other insects, with the deciduous styles (e.g. Waldsteinia and Collria),and epizoochory with the upper deciduous stigmatic part and the lower persistent hooked rostrum, an adhesive organ favouring epizoochory dissemination (e. g. Geum and related taxa). Taihangia is a genus endemic to mesophytic
forest area of northern China. Due to its narrow range and specific habit as well as pubescent styles, neither perfectly adapted to anemochory nor to epizoochory, the genus Taihangia might be a direct progeny of the ancestry of anemochory. Maintaining the diploidy and having an ntermediate sculptural type of pollen, the new genus might probably represent a linkage between anemochory and zoochory (including epizoochory and dispersed by ants).
Experimental evidence from isoperoxidases shows the stable zymograms of root and
roostoks. The anodal isozyme of T. rupestris var. rupestris may be divided into 6 bands:
A, B, C, D, E, F, and T. rupestris var. ciliata into 4 bands: A, B, C, G. The two varietiesof the species share 3 bands: A, B, C. However, D, E and F bands are characteristic of var. rupestris and G band is limited to var. ciliata. As far as the available materials are concerned, the analysis of isoperoxidases supports the subdivision of the species into two varieties. 相似文献
11.
通过扫描电镜对国产水鳖科植物(包括6属13种)的种皮微形态特征进行观察，并作了系统描述。根据种皮细胞形态、外种皮表面纹饰和内种皮内层小瘤状突起的特点将水鳖科植物的种皮微形态特征划分为3种类型，即海菜花型(海菜花属)、水鳖型(水鳖属)和苦草型(苦草属、水筛属、虾子草属和黑藻属)，并作出了分属检索表。本文结果表明，种皮微形态特征可作为该科族、属以及属内种级水平分类的依据，对探讨属间关系和该科的系统发育关系亦具有重要的价值。种皮微形态特征支持Hutchinson(1959)和Eckhardt(1964)将海菜花属和水鳖属分别作为一个独立的族处理的观点。苦草属、水筛属和虾子草属种皮微形态特征的高度相似性表明它们间有密切的联系，不支持将它们置于不同亚科和族的分类处理。黑藻属虽与上述3属近缘，但其外种皮特征则较为独特，因此与水筛属放在不同族中更为合理。本文种皮微形态特征的研究结果支持iki1937)和Shaffer-Fehre(1991b)等关于水鳖科与茨藻科近缘的观点。 相似文献
12.
本文测定了苦苣苔亚科4族、5属、5种植物的核糖体DNA中的内转录间隔区(ITS)序列及5．8s
rRNA基因的3′端序列。这几种苦苣苔亚科植物的ITS-1的长度范围为234～258 bp,ITS-2的长度范
围为218～246bp。Whytockia bijieensis的ITS-1(258bP)和ITS-2(218 bp)在长度、序列及GC含量上
均与其它几个种有较大差异,其代表的尖舌苣苔族可能很早就自苦苣苔亚科的祖先沿单独的一个分支
演化。以w．bijieensis作为功能性外类群,运用PAUP软件分析仅得到一个最简约树。在简约树上,
Cyrtandra umbelliferm、Briggsia longipes和Anna mollifolia形成一个单系群,bootstrap分析对该分支的
支持强度达97％,Chirita crasslfolia位于该分支的基部。由于系统树上Cyrtandra umbellifera代表的
浆果苣苔族和Anna mollifolid代表的芒毛苣苔族均起源于长蒴苣苔族,结合这3个族在形态上存在过渡系列,建议将浆果苣苔族和芒毛苣苔族均并入长蒴苣苔族。 相似文献
13.
对铃兰族(广义)7个属分别作了花粉(17种)扫描电镜观察和叶表皮(12种)的光学显微镜和
扫描电镜观察。花粉可分为8个类型。在狭义的铃兰族的4个属内，花粉全为远极单槽，舟状。它们
的外壁除夏须草属外，都具细孔。夏须草属的花粉外壁则为细皱。 Hutchinson(1934)的蜘蛛抱蛋族
花粉形态变异很大，其中开口箭属和万年青属的花粉为远极单槽，舟形，外壁具穿孔或网纹，而蜘蛛抱
蛋属的花粉则为球状，无萌发孔。其间的显著差异支持Nakai为前两个属建立万年青族(Rohdeae)。
表1归纳了7个属的花粉形态；图1是我们对铃兰族(广义)花粉形态演化的见解。叶表皮观察表明，气
孔器为无规则型，上表皮角质层主要为条纹加厚，或均匀加厚，而铃兰属的角质层秕糠状加厚。7个属的叶表皮特征归纳于表2。 相似文献
14.
本文作者对国产鼠李科枣族6属19种的花粉形态进行了光学显微镜和扫描电镜的观察，根据孔沟交界处四块加厚的程度和所形成的H形明显与否以及纹饰的不同作出了分属检索表。同时根据花粉形态特征讨论了有关属的分类学上的问题。 相似文献
15.
福建柏是我国特有裸子植物之一。它的原胚经过三次有丝分裂，产生8个游离核，然后形成细胞壁。原胚属标准型。开放层细胞与初生胚细胞的比率多数为4:4；少数为5:3或6:2。福建柏具裂生多胚，由于初生胚柄的生长速度不同，引起胚细胞的独立发育，从而产生多胚。 从早期胚胎发育的资料看，福建柏属与柏木属、扁柏属比较类似，它们应属于柏木亚科。福建柏属的系统位置，可能介于扁柏属和圆柏属之间。 相似文献
16.
中国散生竹类的数量分类和确定分类等级的探讨 总被引：1，自引：0，他引：1
In this paper, 21 species representing 13 genera were studied by means of humeri-
cal taxonomic methodes. One geographical and 52 morphological characters were used.
The correlation coefficients were computed by standardized data, and the various clus-
tering methods were performed on the correlation matr x. The UPGMA clustering
method was selected as the optimal one and its results were shown in the form of
dendrograms.
We present a simple method to construct the joint and broken lines by which the
boundary of the genera, subtribes and tribes in the dendrogram is determined.
By means of numerical taxonomic methods, we can easily work out a systematic
dendrogram and the following taxonomic treatments are easily proposed:
(1) Sasamorpha sinica (Keng) Koidz. should be reffered to the genus Sasa Makino
& Shibata.
(2) Pseudosasa amabilis (McClure) Keng f. should belong to the genus Pseudosasa
Makino and should not be referred to the genus Arundinaria Michaux.
(3) The genus Brachystachyum Keng should be considered as a separate one.
(4) The genus Pleioblastus Nakai should not be combined with the genus Arun-dinaria Michaux, but kept as an independent one. 相似文献
17.
系统报道了中国桑寄生科Loranthaceae33种5变种植物的花粉形态，并与澳大利亚
2属6种植物的花粉形态做了比较。通过光学显微镜和扫描电镜观察，国产桑寄生科花粉外壁
纹饰可明显分为两个类型:一种类型为刺状或条状纹饰，另一种为颗粒状纹饰，这与该科的鞘
花族和桑寄生族两个族相吻合。在鞘花族类型中，3合沟、钝刺状或条状纹饰的花粉是基本类
型，合半沟或孔沟形，刺状纹饰的花粉是较进化的类型;在桑寄生族类型中，等极、3合沟、
颗粒状纹饰的花粉是基本类型，异极、副合半沟-合半沟、3沟形和沟形-短沟形或沟孔形、粗
糙或模糊颗粒状纹饰的花粉是较进化类型。根据萌发孔和纹饰可将桑寄生族类型花粉分为3个
类群:类群I包括五蕊寄生属Dendrophtho、梨果寄生属Scurrula、钝果寄生属Taxillus和大苞
寄生属Tolypanthus;类群II仅包括离瓣寄生属Helixanthera;类群III也仅1属，桑寄生属Lor
anthus。在这3个类群中，类群I属于基本的类型，属间花粉差别较小，其中梨果寄生属和钝
果寄生属花粉差别最小，显示出较近的亲缘关系;类群II和类群III皆是较进化类型。 相似文献
18.
中国金缕梅科叶表皮毛的变异与演化 总被引：2，自引：0，他引：2
本文以金缕梅科13属25种植物为代表，在光镜和电镜下观察了其表皮毛的微形态和类型。参
照Theobald的方案，将该科的表皮毛分为四种类型。这些类型在不同亚科和属间的分布呈现出系统演化意义。作者从表皮毛类型的角度讨论了该科的系统演化问题。 相似文献