国产菟丝子属种子形态的观察

本文观察了中国产菟丝子属种子的形态和种皮表面的超微结构。菟丝子属种子表面特征如下： 种脐呈衣领状突起或与晕轮面平齐或下陷;晕轮细胞呈近放射状排列或网状排列或不规则排列;种皮 表面呈条纹状纹饰或脑纹状纹饰或网状纹饰,纹饰上有时具瘤状突起或块状附属物。根据上述特征,可将菟丝子属种子分成三种类型。种皮纹饰可作为分类鉴定和种子检疫的依据。     

滇产菟丝子种子形态的观察

应用解剖镜和扫描电镜观察了产于云南的 3种 12份菟丝子的种子形态 ,结果如下 :( 1)大花菟丝子种脐线形或弧形凹陷 ,晕轮椭圆形具网状纹饰 ,种皮具条状纹饰 ,条纹宽大呈块状 ,绞链状连接 ,排列致密 ;( 2 )中国菟丝子的种脐呈衣领状突起 ,晕轮圆形具不规则网状纹饰 ,种皮具复网状纹饰 ;( 3)日本菟丝子的种脐线形或弧形凹陷 ,晕轮圆形至椭圆形 ,具规则的网状纹饰 ,种皮具规则条状纹饰或网状纹饰 ,条纹狭长 ,排列稀疏 ;( 4 )种子形态不仅可用于菟丝子种及变种的检疫和鉴定 ,而且支持形态聚类分析所得结论。     

中国无患子科的花粉形态及其系统学意义

利用扫描电镜对国产无患子科(狭义,Sapindaceae)23属30种1变种植物的花粉形态进行了观察。结果显示,该科花粉粒多为扁球形,部分为长球形,少数为球形或近球形,极面观多为三角形;从花粉萌发孔类型看,大多数种类具三沟孔,有的形成合沟,少数仅具三孔而无沟;从花粉外壁纹饰看,多数花粉外壁具网状或条纹状雕纹,少数花粉的外壁具刺状或颗粒状纹饰。花粉形态特征支持文冠果亚科(Xanthoceroideae)以及广义鳞花木属(Lepisanthes)概念,并支持仍将茶条木属(Delavaya)置于车桑子亚科(Dodonaeoideae)。观察发现黄梨木(Boniodendron minus)与栾树属(Koelreuteria),龙眼属(Dimocarpus)、荔枝属(Litchi)与韶子属(Nephelium)从花粉形态上表现出较近的亲缘关系。基于花粉形态特征编制了国产无患子科分属检索表。     

金缕梅科系统发育的古孢粉学证据

本文系统描述了现代金缕梅科中主要属的花粉形态特征,并在此基础上运用孢粉学的资料探讨 了金缕梅科的系统分类及其演化规律。 文中还详细记述了金缕梅科中化石花粉的形态、出现的地质时代及分布;并进一步探讨了金缕梅科的地质演进历史。文章认为．早白垩世时期为金缕梅科的发生期,晚白垩世为金缕梅科的发展期。在这一时期金缕梅科中的主要属——金缕梅属Hamamelis、蜡瓣花属Corylopsis,弗特吉属Fothergilla均已出现。被子植物第一次在植物界中占据优势。进入早第三纪时期金缕梅科得到了进一步的发展和完善,花粉形态由三沟型演进出散孔型。最后,本文通过对金缕梅科孢粉形态学的研究和生物地层学的研究,详细的论述了金缕梅科演化的古孢粉学证据。文章认为金缕梅目可能由棒纹粉(Clavatipollenites)直接演进而来,而后再演进金缕梅科中其他各属种。文中还根据孢粉形态学的分析和孢粉生物地层学的研究,提出金缕梅科中的枫香属Liquidambar是和金缕梅科中的主要类群(三沟型)完全不同的两个类群,从而同意枫香属应当从金缕梅科中独立出来,另建立一个阿丁枫科Altingiaceae。     

勾儿茶属和小勾儿茶属(鼠李科)的果实及种子形态研究及其系统学意义

在扫描电镜和解剖镜下研究鼠李科(Rhamnaceae)勾儿茶属(Berchemia)和小勾儿茶属(Berchemiella)共17种植物的果实和种子形态.结果表明：小勾儿茶属的核果1室,具1枚种子,勾儿茶属大多数种的核果2室,每室具1枚种子,但多叶勾儿茶(B．polyphylla)的核果1室较大,具1枚种子,另一室较小而没有种子,该种可能是连接勾儿茶属和小勾儿茶属的中间类群.这两个属的种子形状通常为不规则长椭圆形,种皮纹饰可划分为光滑或几乎光滑、具不明显或稀疏的条纹以及具明显的条纹或沟这三种类型.种皮纹饰的差异对这两个属属下种类的划分具有一定的意义.讨论了与前人研究结果不同之处和可能的原因.     

中国水鳖科植物种皮微形态特征及其系统学意义

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。     

国产蔷薇科绣线菊亚科的花粉形态

本文报道了国产蔷薇科绣线菊亚科(Spiraeoideae)8属9种植物花粉形态。该亚科花粉近球形,极面观三裂圆形。花粉通常较小,最小花粉见于Spiraeapurpurea,为1487(1275～1658)μm×1517(1275～1734)μm,其中Physocarpusamurensis的花粉比较大,为2797(1989～3825)μm×3091(2677～3366)μm。三孔沟,内孔为长方形,部分种内孔明显外突。沟较长,两端较窄,在Physocarpusamurensis观察到合沟现象。合沟出现时通常三沟在一极汇合,在另一极常不汇合。花粉外壁具穴状、条纹-穴状、条纹-网状、条纹状等数种纹饰。迄今为止,在Rosaceae观察到的所有花粉外壁纹饰中,除较为特化的刺状纹外,其余纹饰在该亚科均存在。在Rosaceae所有的花粉外壁纹饰中,穴状纹饰可能是较为原始的类型,条纹状-网状和条纹状依次是较为进化的,而刺状是最进化的纹饰。在Spiraea中,外壁纹饰有相对进化的条纹-网状和条纹状,然而未观察到穴状这一最原始类型,这表明该属及其属下种的分化程度可能较高。但因Spiraea所含种数较大,这一推论有待进一步深入论证。此外,花粉形态特征支持Takhtajan(1997)关于Spiraeoideae亚科下族与属的排序。     

羊蹄甲属植物种子表面微形态观察

利用光镜和扫描电镜对羊蹄甲属21种(含1亚种、2变种)的种子进行观察,结果显示,羊蹄甲属植物的种子颜色、形状和外种皮纹饰多样,还发现种脐位置、假种皮裂片、拟透镜状突起和种皮表面纹饰有一定的相关性:即没有假种皮裂片,拟透镜状突起在种子表面不明显,具网状纹饰的种子其种脐位于种子亚顶部的位置,而非顶部位置。此外,大部分羊蹄甲亚属种子的表面纹饰为皱波状,而显托亚属的纹饰没有皱波状纹饰,却以网状纹饰居多。分析认为,羊蹄甲属植物中种皮网纹状纹饰可能是比较进化的特征;并认为种脐在亚顶部位置,没有假种皮裂片,拟透镜状突起在表面不明显,具网状纹饰的种子应是羊蹄甲属内较进化的式样。     

中国蕨类植物孢子形态的研究 Ⅱ. 中国蕨科

利用扫描电镜对国产中国蕨科Sinopteridaceae植物9属61种6变种的孢子进行了观察。结果表明,该科植物的孢子可分为3种类型：(1)孢子球形,三裂缝;周壁较厚,疏松地包在孢子之外;外壁光滑,表面纹饰由周壁形成,呈网状、嵴状、刺状或皱状。除金粉蕨属Onychium和珠蕨属Cryptogramma外,该科其他属的植物都具此类型孢子。(2)孢子钝三角形,三裂缝;周壁较薄,由周壁和外壁共同形成表面轮廓,表面具疣状或颗粒状纹饰。具此类型孢子的只有珠蕨属。(3)孢子钝三角形,三裂缝,沿裂缝两侧各有一脊状隆起或瘤状纹饰;周壁薄,由外壁形成表面纹饰的基本轮廓;具赤道环、近极脊和远极脊。具此类型孢子的只有金粉蕨属。另外,从孢粉学的角度对该科的分类和系统演化进行了探讨。     

国产爵床科山牵牛属6种、叉柱花属和老鼠簕属各1种植物的花粉形态

报道了国产爵床科Acanthaceae山牵牛属Thunbergia(山牵牛亚科Thunbergioideae)6种、叉柱花属Staurogyne(瘤子草亚科Nelsonioideae)和老鼠簕属Acanthus(老鼠簕亚科Acanthoideae)各1种植物在扫描电镜下的花粉形态。山牵牛属植物的花粉粒为圆球形,均具螺旋状萌发孔,外壁纹饰以光滑或颗粒状为主,偶具棒状突起。具螺旋状萌发孔被认为是该科独特而较原始的花粉特征。叉柱花属的花粉粒为圆球形,具3孔沟,外壁平滑。老鼠簕属的花粉粒为长球形,具3沟,外壁具细网状纹饰或具小穿孔。花粉形态特征支持传统上将上述3属置于3个不同亚科的处理。     

Variation and Evolution of Leaf Trichomes in the Chinese Hamamelidaceae

Leaves of 25 species which cover 13 genera of the Chinese Hamamelidaceae (sensu lato ) were examined by light microscope (LM) and scanning electron microscope (SEM) to reveal the nature and variation of trichomes. The trichomes showed greater diversity under SEM than under LM and naked eyes. Based on Theobald’s scheme, they can be divided into four types: 1. Simple trichomes: Unbranched, curved or straight (Altingia, liquidambar, Semiliquidambar; 2. 2- 4 armed trichomes: Two to four branched (Corylopsis, Loropetalum, sinowilsonia); 3. Stellate trichomes: With more than five branches. They may be tufted (Forthunearia, Loropetalum, sinowilsonia, Hamamelis, Distylium) or storied (Eustigma); 4. Scales: Peltate and flattened. In the genus Rhodoleia, the scales are totally composed of small boat-shaped ones, whereas in the genus Sycopsis they are rotately branched on the verge but unbranched and flattened in the middle. The distribution of trichome types is of grest significance in hamamelidaceous phylogeny. The simple trichomes mainly exist in Liquidambaroideae and Exbucklandioideae, the stellate and 2-4 armed trichomes occur in Hamamelidoideae, and the scales are confined to Sycopsis (Hamamelidoideae) and Rhodoleia (Rhodoleioideae). From this fact, the authors consider that there are two evolutionary lines in the family, i. e. the Disanthoideae- Exbucklandioideae- Liquidambaroideae line and the Rhodoleioideae-Hamamelidoideae line though some subfamilies are isolated. Within Hamamelidoideae, the trichome types also have taxonomic significance. Corylopsis is a primitive group, whereas Eustigma, Distylium and Sycopsis are respectively on the top of evolutionary branches and the other genera are transitional groups. These genera might be separated as tribes, Corylopsideae, Eustigmateae, Distylieae, Sycopsideaeand Hamamelideae. The relationships among these tribes are given in Fig. l.     

Leaf Architecture and Systematics of the Hamamelidaceae Sensu Lato

Hamamelids have a long fossil history and an important fossil record. Their interesting biogeographic relationships indicate a great age. There exist good surveys of the pollen and floral organs of this family whereas it is so far poorly known from leaf architecture. The leaf architecture of all 29 genera with more than 60 among the total of 140 species of the family was surveyed in this work using clearified leaves. It is found that leaf architecture analysis may shed light on the relationships within the family and the conclusion of evolution based on leaf architecture basically accords with that based on others. The major categories of leaf architecture of Hamamelids observed in this work are as follows: leaf form, leaf margin, tooth type, venation, marginal ultimate venation, areolation and trichome. It must be emphasized that of all these characters the tooth type is the most stable and useful for systematics. In this work a new tooth type is recognized under the name altingioid. Teeth of this type are obviously asymmetrical, with a persistent transparent gland on the top, and with their lateral veinlets free, not reaching the medial vein. All three genera of the subfamily Liquidambaroideae have this tooth type, whereas most leaves of the rest genera of this family have fothergilloid teeth, which are basically symmetrical, without glands. The venation in the fothergilloid tooth is almost the same as that in the altingioid tooth, the only difference being that the lateral veins on the abaxial side of the altingioid teeth are usually absent or very weak and short if present. The present authors consider that the subfamily Liquidambaroideae has to be separated from the family Hamamelidaceae sensu lato and treated as an independent family, Altingiaceae, on the basis of the special tooth type. different pollen morphology and flower structure. The stability of tooth type may serve classification not only of order and family level, but also of tribe, genus and species level with the help of characters of teeth, such as shape, size, density, distribution, single or double, with or without glands. By comparison of Hamamelidaceae and Altingiaceae with some primitive families of subclass Hamamelidae, namely, Trochodendraceae, Tetracentraceae, Cercidiphyllaceae, Eupteleaceae and Platanaceae, the putative evolutionary trend of tooth types is outlined as follows: ↑ altingioid Chloranthoid → Cercidiphylloid →platanoid → fothergilloid In general evolutionarytrend of teeth within these families is reduction and simplification in structure.     

四药门花属及其近缘植物ITS区序列分析和系统学意义

测定和分析了四药门花等１３种金缕梅科（Ｈａｍａｍｅｌｉｄａｃｅａｅ）植物的核糖体ＤＮＡ转录间隔区（ＩＴＳ区）及５８Ｓ编码区的序列。应用最大简约法构建的分子系统树表明：被分析的金缕梅亚科（Ｈａｍａｍｅｌｉｄｏｉｄｅａｅ）植物形成一个单系类群,亚科内及其中的金缕梅族（Ｈａｍａｍｅｌｉｄｅａｅ）内部呈复系演化（ｐｏｌｙｐｈｙｌｅｔｉｃ）的特征;支持秀柱花族（Ｅｕｓｔｉｇｍａｔｅａｅ）（含秀柱花属Ｅｕｓｔｉｇｍａ、牛鼻栓属Ｆｏｒｔｕｎｅａｒｉａ和山白树属Ｓｉｎｏｗｉｌｓｏｎｉａ）成立以及将蚊母树族（Ｄｉｓｔｙｌｉｅａｅ）与弗特吉族（Ｆｏｔｈｅｒｇｉｌｅａｅ）合并的观点,此结果与Ｅｎｄｒｅｓ（１９８９）系统接近;金缕梅族中金缕梅属（Ｈａｍａｍｅｌｉｓ）与弗特吉族中的弗特吉属（Ｆｏｒｔｈｅｒｇｉｌａ）、银缕梅属（Ｓｈａｎｉｏｄｅｎｄｒｏｎ）和水丝梨属（Ｓｙｃｏｐｓｉｓ）系统发育关系密切;四药门花属（Ｔｅｔｒａｔｈｙｒｉｕｍ）与木属（Ｌｏｒｏｐｅｔａｌｕｍ）属于同一个单系类群,它们与Ｈａｍａｍｅｌｉｓ的亲缘关系较远     

Phylogenetic relationships in the Hamamelidaceae: Evidence from the nucleotide sequences of the plastid genematK

The Hamamelidaceae is a family that bridges the basal elements of the Rosidae and the lower Hamamelidae, thus a better understanding of the phylogeny of the family is important for clarifying evolutionary patterns in the diversification of eudicots. However, subfamilial as well as tribal relationships in the Hamamelidaceae have been controversial. Nucleotide sequences of the chloroplast genematK were used to study the intergeneric relationships of the family. In the phylogenetic trees, constructed using parsimony analysis, the clade containingAltingia andLiquidambar (Altingioideae) is sister to a clade that includes all other Hamamelidaceae.Exbucklandia andRhodoleia form a clade, suggesting a close relationship between the two genera.Disanthus is sister to the monophyletic Hamamelidoideae. The paraphyletic arrangement ofDisanthus, Mytilaria andExbucklandia with respect to the Hamamelidoideae does not support the combination of these genera in one subfamily. In the Hamamelidoideae, thematK phylogeny supports the monophyly of several previously recognized groups with modifications, including the tribes Eustigmateae (incl.Molinadendron), Fothergilleae (excl.Molinadendron andMatudaea), and the subtribe Dicoryphinae. However, the Hamamelideae as traditionally circumscribed is polyphyletic. Apetaly has evolved three times independently in the Hamamelidoideae.     

Ovules and seeds in Acalyphoideae (Euphorbiaceae): structure and systematic implications

Acalyphoideae, the largest subfamily of Euphorbiaceae, are investigated with respect to ovule and seed structure on the basis of 172 species of 80 genera in all 20 tribes of Acalyphoideae sensu Webster. All species of Acalyphoideae examined have bitegmic ovules with a non-vascularized inner integument. However, noticeable differences exist among and sometimes within the genera in the thickness of the inner and outer integument, the presence or absence of vascular bundles in the outer integument, whether ovules are pachychalazal or not, the presence or absence of an aril, seed coat structure (in terms of the best-developed mechanical cell-layer), and the shape of cells constituting the exotegmen. For the latter two characters, two different types of seed coat (i.e., "exotegmic" and "exotestal") and three different types of exotegmic cell (i.e., palisadal, tracheoidal and ribbon-like) were distinguished. Comparisons showed that three tribes Clutieae, Chaetocarpeae and Pereae are distinct from the other Acalyphoideae as well as from the other Euphorbiaceae in having an exotestal seed coat with a tracheoidal exotegmen. The tribe Dicoelieae is also distinct from the other Acalyphoideae in having an exotegmic seed that is composed of ribbon-like cells of exotegmen (i.e., cells both longitudinally and radially elongated, sclerotic and pitted). The tribe Galearieae, which should be treated as a distinct family Pandaceae, is also distinct from the other Acalyphoideae in having an exotegmic seed with a tracheoidal exotegmen (i.e., cells longitudinally elongated, sclerotic and pitted). The remaining genera of Acalyphoideae always have an exotegmic seed with a palisadal exotegmen (i.e., cells radially elongated, sclerotic and pitted). The shared palisadal exotegmen supports the close affinity of Acalyphoideae (excluding five tribes) with Crotonoideae and Euphorbioideae. Within the remaining genera of Acalyphoideae, a significant diversity is found in ovule and seed morphology with respect to the thickness of the inner and outer integument, the size of chalaza, vascularization of an outer integument and an aril.     

Neogene Corylopsis seeds from eastern Tennessee

A new fossil species of Corylopsis (Hamamelidaceae), C. grisea Quirk & Hermsen sp. nov, based on seeds from the early Pliocene Gray Fossil Site (GFS), eastern Tennessee, USA, is described. The assignment of the seeds to Hamamelidaceae, subfamily Hamamelidoideae, is based on the overall size of the seeds, smooth testa, lack of a seed wing, and the presence of a terminal hilar scar. The assignment to the genus Corylopsis is based on seed size as well as the presence of a hilar facet, in addition to the hilar scar. Although Corylopsis persists only in East Asia today, its fossil record indicates that the genus was widespread across the Northern Hemisphere in the past. Prior to its discovery at GFS, Corylopsis was only known from the Paleogene in North America. The presence of C. grisea at GFS extends the fossil record of Corylopsis in North America to the Neogene and reinforces the interpretation of GFS as a forested refugium that provided a relatively moist, equable environment where subtropical to warm temperate plants could persist during a time of cooling and drying in the continental interior of North America. Its presence provides additional evidence for the biogeographic connection between the GFS paleoflora and the modern flora of eastern Asia.     

The position of Najas within the subclass Alismatidae (Monocotyledones) in the light of new evidence from seed coat structures in the Hydrocharitoideae (Hydrocharitales)

SHAFFER-FEHRE, M., 1991. The position of Najas within the Alismatidae (Monocotyledones) in the light of new evidence from seed coat structures in the Hydrocharitoideae (Hydrocharitaceae). This paper gives details of seed coat structure in several genera of the Hydrocharitoideae (Hydrocharitaceae) and of Najas (Najadaceae). The taxonomic position of Najas L., as a genus or as the basis of a higher taxonomic category, has changed with the publication of every new system of classification in which it was considered. In the light of evidence derived from seed coat anatomy, particularly that of the testa, and from the presence of endotegmen tuberculae, Najas is placed in the enlarged tribe Stratioteae in the subfamily Hydrocharitoideae (Hydrocharitaceae).     

Karyomorphology and evolution in some Hamamelidaceae and Platanaceae (Hamamelididae; Hamamelidales)

Karyomorphology in 14 species of 12 genera representing a variation of Hamamelidaceae and in one species of Platanaceae (Platanus only) is investigated in an effort to contribute to an understanding of chromosome evolution and inter- and intrafamilial relationships. All genera investigated show similar chromosome features at resting stage and prophase, excepting that at resting stageRhodoleia shows the simple, rather than the simple-complex, chromocenter type as in other genera. At metaphase all the genera investigated of Hamamelidaceae, like other ‘lower’ Hamamelididae, have chromosomes with median centromeres (m-chromosomes), those with submedian centromeres (sm-chromosomes) and those with subterminal (or terminal) centromeres (st-t-chromosomes) at different frequencies, although frequencies ofst-t-chromosomes are always less than 33%. InPlatanus,m-chromosomes are lacking and insteadst-t-chromosomes are predominant (86%), a feature seemingly very specialized. We confirmedx=7 in Platanaceae,x=12 in Hamamelidoideae and Rhodoleioideae, andx=8 in Exbucklandioideae and Altingioideae (Hamamelidaceae). An analysis of chromosome morphology supports the hypothesis thatx=12 in the former two subfamilies is of tetraploid origin fromx=6, rather than of triploid origin fromx=8. We further give brief comments on the suprageneric classification of Hamamelidaceae that was recently proposed by Endress.     

Systematic and phylogenetic significance of the seed coat in the shrubby African Iridaceae, Nivenia, Klattia and Witsenia

MANNINGJ. C. & GOLDBLATT, P., 1991. Systematic and phylogenetic significance of the seed coat in the shrubby African Iridaceae, Nivenia, Klattia and Witsenia. The seeds of Nivenia, Klattia and Witsenia, a natural alliance within Nivenioideae, are among their most distinctive features, and seed number and shape constitute at least two synapomorphies for this monophyletic lineage. In this paper we survey the structure of the seed surface of five species of Nivenia and one each of Klattia and Witsenia by scanning electron microsopy (SEM), and study the development of the seed coat in a representative species of each of the three genera. Outgroups for comparison were selected from genera inside and outside the subfamily. The six genera of Nivenioideae are united in having a 3 (– 2) seriate outer integument but the shrubby genera are unique in the family in their tangentially flattened ovules which mature into depressed, flat, scutiform seeds. They display a range of variation in seed coat characters but are specialized in the subfamily and family in having a transparent outer integument. Other genera have pigmented deposits in the outer epidermis of the outer integument. Nivenia and Witsenia are further specialized in having a partially exfoliating outer integument. Klattia is unique among the shrubby genera in having deposits in the second layer of the tegmen, in retaining an intact outer epidermis of the tegmen, and in the fusiform shape of the epidermal cells and striate surface of the seed. Our results are incorporated in a cladogram that expresses our current understanding of the phylogenetic relationships of Nivenioideae.