SEED COAT MORPHOLOGY IN CORDYLANTHUS (SCROPHULARIACEAE) AND ITS TAXONOMIC SIGNIFICANCE

A study of seed coat sculpturing in Cordylanthus (Scrophulariaceae—Rhinantheae) using the scanning electron microscope (SEM) shows that seed surface patterns are characteristic and constant for a given species or a group of species. Seeds of 23 species were examined and classified into four types (irregularly crested, deeply reticulate, shallowly reticulate, and irregularly striate) based on differences in the reticulated seed coat. Anatomical studies of sections with the light microscope show that the reticular patterns result from enlargement of the epidermal cells of the integument, followed by formation of characteristic wall patterns through lignification. Seed characters furnish useful data for formulating the taxonomy of Cordylanthus both on the sectional and subsectional level and for the delimitation of certain species. Seed coat morphology offers evidence for including the genus Dicranostegia in Cordylanthus and for maintaining C. hispidus and C. palmatus as separate species. The distinctness of two seed coat types within section Cordylanthus suggests two major phylogenetic lines within this section.     

THE TAXONOMIC IMPLICATIONS OF POLLEN MORPHOLOGY IN SOME SOUTH AMERICAN SPECIES OF MIMULUS (SCROPHULARIACEAE)

The pollen grains of South American hexaploid representatives of the Mimulus glabratus complex, section Simiolus, and M. bridgesii, a South American species sometimes included in this complex and sometimes in section Paradanthus, were examined by light and scanning electron microscopy. Mimulus bridgesii has (6-) 4–5-zoniaperturate grains nearly identical to those observed in a complex of species in section Paradanthus. South American members of the M. glabratus complex (M. bridgesii excluded) have the irregularly synaperturate, ± spiraperturate pollen typical of section Simiolus (sensu Grant). Treatment of M. bridgesii as a palynologically aberrant member of section Simiolus is not supported by what is known about the evolution of pollen types in Mimulus and the evolution and dispersal of the M. glabratus complex.     

POLLEN MORPHOLOGY IN THE SELAGINEAE,MANULEAE (SCROPHULARIACEAE), AND SELECTED GLOBULARIACEAE,AND ITS TAXONOMIC SIGNIFICANCE

The pollen grains of 22 genera and 182 species of Selagineae, Manuleae, and selected Globulariaceae were examined by light and scanning electron microscopy of whole and fractured pollen. Grains of the Selagineae and most Manuleae have trizonicolporate aperatures with long, unconstricted ectocolpi; clearly delimited margos; psilate colpus membranes; lalongate transverse endocolpi extending beyond the boundaries of the ectocolpi; thickened endoaperture margins; semitectate, reticulate to microreticulate exines; and psilate, simplicolumellate muri. In the Globulariaceae, Globularia has spinulose, microperforate exines and undifferentiated ectocolpus margins, and both Globularia and Poskea have granular to spinulose colpus membranes, lolongate endoapertures included within the ectocolpi, and unthickened endoaperture margins. These pollen data support postulated relationships between Selagineae and Manuleae, but pollen grains of Selagineae and Globulariaceae are distinct, and pollen morphology does not correlate with proposals combining these taxa in Globulariaceae or Selaginaceae. Pollen morphology in Glumicalyx is indistinguishable from that in most Manuleae and supports transfer of this genus to the Manuleae from the Digitaleae. Differences in pollen morphology supplement established morphological distinctions between Globularia and Poskea, but the pollen evidence does not support published infrageneric classifications in Globularia or postulated relationships between Selagineae and Gratioleae or Selagineae and Lagotis.     

中国榆属花粉形态研究及其分类意义

用光学显微镜和扫描电镜观察了榆属(Ulmus L.)5个组中19个种的花粉形态,并对我国具有的4组15种进行了统计学观测,对个别种的花粉外壁作了透射电镜超微结构研究。该属花粉萌发孔为4—7个,因种而异,分别为4—5、4—6和4—7孔。不同孔数的花粉含量存在差异。花粉外壁纹饰可区分为疣状、条块状、脑纹状、粗拟网状和细拟网状等5种主要类型。外壁超微结构表明,该属花粉无典型柱状层的分化。并就一些属内有关的分类学问题进行了讨论。     

中国特有属─—东俄芹属的花粉形态及其分类学意义

利用光学显微镜和扫描电镜观察了伞形科东俄芹属（ＴｏｎｇｏｌｏａＨ．Ｗｏｌｆｆ）７个种的花粉形态,结果表明：除宜昌东俄芹Ｔ．ｄｕｎｎｉｉ（Ｂｏｉｓｓｉｅｕ）Ｈ．Ｗｏｌｆｆ和城口东俄芹Ｔ．ｓｉｌａｉｆｏｌｉａ（Ｂｏｉｓｓｉｅｕ）Ｈ．ｗｏｌｆｆ的花粉为矩形类型外,其它几种的为菱形类型,然而并非都是原始的或典型的菱形,而是处于分化过程中的菱形类型,如纤细东俄芹Ｔ．ｇｒａｃｉｌｉｓＨ．Ｗｏｌｆｆ,大东俄芹Ｔ．ｅｌａｔａＨ．Ｗｏｌｆｆ的花粉形态,表现出近菱形、近椭圆形和近矩形的特征,在我们近期的工作中曾涉及滇芎属ＰｈｙｓｏｓｐｅｒｍｏｐｓｉｓＨ．Ｗｏｌｆｆ类似的花粉形态及分化情况,从花粉资料启示,东俄芹属可能与滇芎属近缘。     

中国兜被兰属植物的花粉形态及其分类意义

兜被兰属Neottianthe全世界共约12种,中国均有分布,其中9种为我国所特有。本属花粉形态 和组成都很特殊,它是由许多单粒花粉粘结在一起形成复合花粉——花粉小块,其形状一般为狭长的三 棱锥体形。外壁表面具5种纹饰类型:(A)近光滑,或具十分微弱的小凹陷;(B)外壁具穿孔状纹饰; (c)外壁具沟渠状纹饰;(D)外壁具拟网状纹饰;(E)具典型的网状纹饰。奉属有些种类,例如:N．cal- cicola,N．monophylla,N．pseudo-diphylax和N．cucullata等4种在分类上还存在许多问题,有些分类 学家把N.calcicola,N.monophylla,N.pseudo-diphylax 3种均归并于N．cucullata。孢粉学资料表 明上述4个种花粉特征完全不同,因此,上述4种仍应各自独立为种。最后,强调指出N．camptoceras的花粉形状和外壁纹饰等特征在本属为特殊类型。     

山茶属的花粉形态及其分类学意义

本文对山茶属(Camellia L.)18个组27个代表种的花粉进行了光学显微镜、扫描电镜和大部分进行了透射电镜的观察,并对花粉大小、形状、外壁纹饰和超微结构等作了综合的比较。结果表明,其形状和大小差异不很明显。花粉壁的层次、厚度和不同层次的比例,如复盖层与柱状层以及外壁外层与外壁内层的比例等也没有显著的差异。但花粉壁的纹饰特征在扫描电镜下显示出较大的差异,具有较重要的分类学价值。根据其纹饰特征,可以把山茶属花粉大致区分为六个类型:皱疣状纹饰;粗瘤状纹饰;颗粒状至皱-颗粒状纹饰;穴-网状纹饰;皱沟状纹饰及皱波-念珠状纹饰。孢粉学上区分的类型不完全与各个学者从植物形态上划分的组相一致。其中管蕊茶 Camellia lanceolata的纹饰非常特殊(粗瘤状),其外壁表面很象牛心果(Annona reticulata)的外形特征,为其重新分类提供孢粉学依据。     

栝楼属花粉形态研究及其在分类学上的意义

本文收集了国内外栝楼属Trichosanthes 31种1变种,在光学显微镜和扫描电镜下,进行了花粉粒形态的比较观察。该属花粉粒为3孔沟型,外壁表面纹饰可分为四个类型,即：疣状或皱波状(小苞组),粗网状(大苞组),细网状或光滑(叶苞组),近光滑或皱波状(王瓜组)。这四个类型的划分与植物形态分类基本一致,可作为分组及分种的依据之一。花粉特征支持将叶苞组分为叶苞亚组和柔毛亚组,如叶苞亚组有明显的沟,而柔毛亚组没有。     

岩梧桐属的花粉形态及其分类学意义

本文通过光学显微镜和扫描电镜对岩梧桐属Wightia Wall.花粉进行了深入的观察,并与紫葳科和玄参科部分属种作了详尽的比较。结果认为,从花粉的大小等级、萌发孔特征、外壁内外层比例等看,岩梧桐属花粉与玄参科的花粉更类似,而与紫葳科的相距较大。孢粉学支持把岩梧桐属置于玄参科。该属的国产种,根据花粉的大小和外壁纹饰特征的差异划分为两个种较为合理和自然,不该合并为一个种。     

MORPHOLOGY,EVOLUTION, AND TAXONOMIC SIGNIFICANCE OF THE INFLORESCENCE IN CORDYLANTHUS (SCROPHULARIACEAE)

The genus Cordyhmthus has considerable diversity in its inflorescences while the other genera of tribe Rhinantheae (Scrophulariaceae) uniformly have racemes or spikes. Four distinct inflorescence types are recognized and their homologies and evolutionary history are postulated. Thus it is suggested that the basic florescence type, the elongated spike (Type I), has undergone evolutionary reduction to a few-flowered spike and ultimately to a single-flowered florescence (Type II). Further evolution involving processes of compaction and clustering of the single-flowered florescences has resulted in glomerulate clusters (Type III) and spiciform clusters (Type IV). Knowledge of inflorescence homologies and distribution of the four inflorescence types in the genus has been of considerable aid in formulating a new infrageneric classification. Using evidence primarily from inflorescence, floral, and seed morphology, as well as from geographical distribution and ecology, a classification is proposed establishing three subgenera, namely subg. Dicranostegia, subg. Hemistegia, and subg. Cordylanthus, the last with three sections, sect. Cordylanthus, sect. Anisocheila, and sect. Ramosi.     

POLLEN MORPHOLOGY IN THE GENERA MONTTEA AND MELOSPERMA (SCROPHULARIACEAE)

Pollen of the scrophulariaceous genera Melosperma and Monttea was studied with light and scanning electron microscopy. Both have single, radiosymmetric, isopolar, trizoniaperturate pollen grains with usually ruptured colpus membranes, tectate-perforate to semitectate exines with a columellate interstitium and pitted or perforate nexines. Intergeneric differences in pollen morphology are established based on the differential correlation of sculpturing characters. Comparisons of the pollen of Melosperma and Monttea with that of the tribe Minuleae sensu stricto reveals no difference in the case of Melosperma and the existence of intermediate morphologies and “reticulate” similarities in the case of Monttea; the taxonomic significance of this morphological intergradation is considered. The transfer of Oxycladus aphyllus to Monttea is consistent with the pollen evidence, but proposed affinities between Monttea and tribe Antonieae of the Loganiaceae are not supported.     

UNUSUAL CYTOLOGICAL PATTERNS IN MICROSPOROGENESIS AND POLLEN DEVELOPMENT OF EVOLUTIONARY SIGNIFICANCE IN THE MIMULUS GLABRATUS COMPLEX (SCROPHULARIACEAE)

Four populations of Mimulus glabratus var. utahensis Pennell from the Great Basin and seven of M. glabratus var. fremontii (Bentham) Grant from the New Mexico–Texas–northeastern Mexico area were intercrossed and their F₁ hybrids grown. Cytology and fertility of both the parental populations and the F₁ hybrids were studied. The following cytological abnormalities were observed in microsporogenesis: cytomixis, the stretching of one or more chromosomes from cell to cell; multipolar divisions, separation of the chromosome complement into two or more parts; unequal disjunction; spontaneous polyploidization; and the production of encapsulated pollen tetrads. Typically, these abnormalities were rare or not observed in the parents, were rare in the intravarietal hybrids, but were more common in the intervarietal hybrids. They were closely associated with, in fact were the probably causes of, barriers to gene exchange between these two diploid (n = 15) varieties. Thus, the apparent causes of barriers to gene exchange in intervarietal hybrids are the likely mechanisms for the evolution of aneuploidy and polyploidy so characteristic of the rest of the Mimulus glabratus complex.     

POLLEN MORPHOLOGY IN THE GENUS ERYTHRONIUM (LILIACEAE) AND ITS SYSTEMATIC IMPLICATIONS

Pollen morphology was examined in 40 samples from 19 species in the genus Erythronium (Liliaceae) using scanning (SEM) and transmission electron microscopy (TEM). Pollen grains are monosulcate monads, except for a plant of E. oregonum which has dyad grains. North American and European species are characterized by reticulate exine sculpture composed of various degrees of wavy muri and variably-sized lumina. The most distinctive feature of exine sculpture in the genus is exhibited by the Asian species E. japonicum, which has a unique reticulate pattern composed of striate muri and a distinctive exine structure without columellae. The distinctness of E. japonicum pollen suggests that it has specialized in isolation from species in North America and Europe.     

中国独活属花粉形态及分类学和进化意义

中国独活属约26种3变种。本文通过光学显微镜和扫描电镜观察,较系统地分析了21种2变种的花粉。研究结果表明:该属花粉基本为矩形类型,少数种具赤道收缩型。综合中国独活属形态解剖方面的相关特征,将中国独活属分为两大类群,并讨论了独活属的系统位置及其演化趋势。     

锦鸡儿属花粉形态及其分类意义

在光学显微镜和扫锚电镜下对锦鸡儿属31种2变种植物花粉形态进行了观察。根据外壁表面纹饰,可分：类型I,表面具小穿孔;类型II, 具网状纹饰。 在类型II中据网眼大小和网脊宽度特征又分为两个亚类型。 根据花粉体积大小,可分4个类型。本属植物花粉形态较为一致,表明是一个自然类群。组、 系的花粉形态特征与一般形态变异不一定相对应,即形态上有明显区别的种类,在花粉形态上未必有很大区别,仅一些种类及矮锦鸡儿系 Ser. Pygmaeae的花粉形态相近。 本属花粉形态在种下等级的变异, 特别是青藏高原分布的种类的变异较为明显,例如 C.bicolor,C. jubata,C. erinacea 与各自的近缘种类。花粉形态为分类处理提供了参考。本属植物花粉形态是从表面具小穿孔向具网状纹饰演化,对应于羽状叶类群向掌状叶类群演化。     

中国松蒿属（玄参科）的分类研究

对东亚特有属－松蒿属进行了分类学订正。松蒿属特产东亚温带地区,有５种,我国全产。其中木里松蒿为１新种;黑籽松蒿为１新记录种;本文还报２个新异名。     

东北槭属的花粉形态及其在分类上的意义

本文采用光学显微镜和扫描电镜,对我国东北地区械属10种变1种的花粉形态进行了观察。本属花粉近球形式长球形,赤道面观为近圆形或窄椭圆形,极面观为3裂圆形,极轴长2.-40μm;具3沟,沟明显;外壁通常具条纹状纹饰,稀具网状纹饰。从观察材料看,本属花粉可归之为2个类型:(1)色木槭型:(Mono maple type):外壁具条纹状纹饰,条纹宽0.250.50μm;(2)梣叶槭型(Ash-leaved maple type):外壁具条网状纹饰,网眼形状不规则,多为长形,长约3μm;网脊宽0.7μm,这正好与分类学家根据形态划分的个亚属相吻合。花粉形态所提供的资料,也支持色木槭(Acermono Maxim.)和平基槭(A.truncatum Bge.)作为两个独立种的处理意见。     

中国沙拐枣属植物花粉形态及其在地层研究中的意义

通过光学显微镜和扫描电镜观察了中国沙拐枣属(Calligonum L.)11种植物的花粉形态。按扫描电镜下的外壁纹饰分类,该属花粉可分为4种类型,即:网纹-穴状具圆形或近圆形网眼、网纹-穴状具多角型网眼、网纹-穿孔和网纹-穿孔或小沟渠。它们的演化趋势是从前面类型依次向后面类型演化。根据花粉内孔的形状,沙拐枣属植物花粉可区别于蓼科其它属植物三孔沟类型花粉。     

中国北部绣线菊属的花粉形态及分类学意义

本文用光学显微镜和扫描电镜观察了中国北部绣线菊属ＳｐｉｒａｅａＬ．２１种及６个变种的花粉形态,描述了外壁纹饰的形态特征,指出了外壁纹饰特征在分类上的意义。绣线菊属的花粉为球形至长球形,外壁纹饰为条网状至条纹状。外壁纹饰类型不具有属内分组意义,但对一些种类具有一定的分类价值。花粉形态支持将曲枣绣线菊Ｓ．ｆｌｅｘｕｏｓａＦｉｓｃｈ。并入石蚕叶绣线菊Ｓ．ｃｈａｍｏｅｄｒｙｆｏｌｉａＬ．的观点［Ｍａｘｉｍｏｗｉｃｚ,Ｃ．Ｊ．（１８７９）、Ｒｅｈｄｅｒ,Ａｉ．（１９４０）］,不同意将蒙古绣线菊毛枝变种Ｓ．ｍｏｎｇｏｌｉｃａＭａｘｉｍ．ｖａｒ．ｔｏｍｅｎｔｕｌｏｓａＹｕ提升为贺兰山绣线菊Ｓ．ｔｏｍｅｎｔｕｌｏｓａ（Ｙｕ）Ｙ．Ｚ．Ｚｈａｏ［赵一之（１９８７）］。     

中国东北牻牛儿苗科(Geraniaceae)种子形态特征及其分类学意义

本文对中国东北牛儿苗科(Geraniaceae)二属(太阳花属Erodium, 老鹳草属(Geranium)计14种(species)1变种(Variety)和1变型(form)植物的种皮亚显微结构(SEM)及种子形态进行了研究.结果表明, 太阳花属与老鹳草属植物无论从种子形状, 长宽比, 还是种皮初级雕纹及次级雕纹形态都表现出明显差异。在老鹤草属下种及种下等级的鉴定和划分上, 种皮微形态及种子形态特征提供了大量有价值的信息。