Floral development in Adonideae (Ranunculaceae)

Floral development and floral phyllotaxis in species of Adonis, Callianthemum, and Trollius (Ranunculaceae) were studied with scanning electron microscopy. The floral organs are initiated in spiral sequence and the flowers have spiral phyllotaxis. The sepal primordia are broad, crescent-shaped, and truncate, but those of petals, stamens, and carpels are rather hemispherical. A relatively long plastochron appears to be present between the last sepal and the first petal as compared with the short and equal plastochrones of all subsequent floral organs. Maturation of the stamens within the androecium appears to be centripetal. The carpels have a short ascidiate zone. Placentation is uniformly lateral, even in Adonis and Callianthemum, which have only one fertile ovule per carpel (versus median in other genera of Ranunculoideae with a single fertile ovule). In Adonis and Callianthemum at the tip of the carpel the ventral slit is gaping and the stigma is broadly exposed, whereas in Trollius the stigma is narrower and more pronouncedly decurrent along the ventral slit. The petals in Callianthemum and Trollius are more conspicuously delayed in development than those in Adonis as compared with sepals and stamens. A short carpel stipe is formed early in Callianthemum but later in Adonis and Trollius. In Trollius farreri (commonly having only five carpels in contrast to other species of Trollius) the carpels form a single (spiral) series. Thus floral development is similar in all three genera and, at a lower level, Adonis and Callianthemum are especially close but have different autapomorphies, which reflects the current classification of the genera.     

Floral morphogenesis in Euptelea (Eupteleaceae, Ranunculales)

BACKGROUND AND AIMS: Based on molecular phylogenetic studies, the unigeneric family Eupteleaceae has a prominent phylogenetic position at or near the base of Ranunculales, which, in turn, appear at the base of eudicots. The aim of the present paper is to reveal developmental features of the flowers and to put the genus in a morphological context with other basal eudicots. METHODS: Flowers in all developmental stages of Euptelea pleiosperma were collected in the wild at intervals of 7-10 d in the critical stages and studied with a scanning electron microscope. KEY RESULTS: Remnants of a perianth are lacking throughout flower development. Floral symmetry changes from monosymmetric to asymmetric to disymmetric during development. Asymmetry is expressed in that the sequence of stamen initiation is from the centre to both lateral sides on the adaxial side of the flower but starting from one lateral side and proceeding to the other on the abaxial side. Despite the pronounced floral disymmetry, a dimerous pattern of floral organs was not found. The carpel primordia arise between the already large stamens and alternate with them. Stamens and carpels each form a somewhat irregular whorl. The carpels are ascidiate from the beginning. The stigma differentiates as two crests along the ventral slit of the ovary. The few lateral ovules alternate with each other. CONCLUSIONS: Although the flowers have some unusual autapomorphies (wind pollination, lack of a perianth, pronounced disymmetry of the floral base, long connective protrusion, long temporal gap between androecium and gynoecium initiation, small space for carpel initiation), they show some plesiomorphies at the level of basal eudicots (free carpels, basifixed anthers, whorled phyllotaxis), and thus fit well in Ranunculales.     

Taxonomical investigations onHelleborus viridis s. l. (Ranunculaceae) in Northern Italy

The taxon commonly namedHelleborus viridis in Lombardy (NW. Italy) differs from both, subsp.viridis and subsp.occidentalis, and is shown to fall within the variation range ofH. odorus subsp.laxus which has been reported so far for NE. Italy only. TrueH. viridis within Italy grows only in the Maritime Alps.     

Development of flowers and inflorescences of Circaeaster (Circaeasteraceae, Ranunculales)

The flower organs of Circaeaster are spiral in origin. The primordia of the tepals, stamens and carpels are almost the same in shape and size in early development. Carpel conduplication takes place only in the middle part of the carpel. The basal part of the carpel differentiates into a short stalk and the upper part into the style and the stigma. Flower development is similar to that of Kingdonia. Floral development of Circaeaster is compared with that of other Ranunculales.     

Floral development in Anemoneae (Ranunculaceae)

The floral development of two Clematis species and four Anemone species (including Pulsatilla) (Anemoneae, Ranunculaceae) is described. Shared features are: (1) sepals shortly after initiation broad, crescent‐shaped, as opposed to the other organs, which are narrow and hemispherical; (2) outermost organs of the androecium often smaller than the others and sometimes sterile; (3) carpels ascidiate, with distinctive stalk, stigma papillate, decurrent; the carpels have one median fertile ovule and a few lateral sterile ovules in all species studied; the fertile ovule appears before the carpel closes. Generic differences are: (1) In Clematis, four sepals are initiated in two pairs; sometimes one of the sepals in the second pair appears to be divided into two organs (double position) resulting in a pentamerous perianth; the first eight stamens are positioned in two alternating whorls, the outer whorl alternating with the four sepals. In Anemone, the perianth organs, if five, are initiated in spiral sequence; in the Pulsatilla group of Anemone, six sepals are initiated in two whorls; the first three organs of the androecium (staminodes) alternate with the inner sepals. (2) Further androecial organs are mostly in complex whorls (i.e. including double positions) in Clematis, but in an irregular spiral or in irregular complex whorls in Anemone. (3) Anther maturation is largely centripetal in Clematis, but centrifugal or bidirectional in Anemone. In Clematis macropetala, the outermost organs of the androecium lack anthers and the filaments expand and become petal‐like. In contrast, in the Pulsatilla group of Anemone, these organs retain sterile anthers and become small, capitate organs. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 162 , 77–100.     

Genome size in Bulgarian Centaurea s.l. (Asteraceae)

Thirty-nine species and subspecies of the genera Centaurea, Colymbada, Psephellus and Cyanus (all included in Centaurea s.l.) including many rare and endemic taxa of preponderantly Bulgarian distribution have been investigated with Feulgen DNA image densitometry for holoploid and monoploid genome size (C- and Cx-values). Cyanus varies gradually 2.17-fold between 0.74 pg and 1.56 pg (1Cx). In the remaining taxa two major genome size groups are found, which differ about 1.8-fold in Cx-value. Low values occur in Centaurea subgenera Acrolophus, Solstitiaria, Phalolepis (0.77 pg to 0.90 pg, 1Cx) and Jacea (0.95 pg to 1.09 pg, 1Cx), high values in the genera Colymbada (1.65 pg to 1.93 pg, 1Cx) and Psephellus (1.79 pg, 1Cx, in P. marschallianus). Cx-values support a distinction of Colymbada from Centaurea. Genome size variation is discussed with regard to phylogeny, life form (annual versus perennial), polyploidy, chromosome basic numbers, altitude of occurrence and climate, endemism, and rarity.     

Female flowers and systematic position of Picrodendraceae (Euphorbiaceae s.l., Malpighiales)

This is the first comparative study of floral structure of the recently established new family Picrodendraceae (part of Euphorbiaceae s.l.) in Malpighiales. Nine species of eight (out of ca. 28) genera were studied. Female flowers are mainly completely trimerous, and in such flowers the perianth consists of one or two whorls of sepals. A floral disc (which probably functions as a nectary) is mostly present. The free parts of the carpels are simple (unbranched) in all ten species studied. Each carpel contains two crassinucellar, anatropous or hemitropous, epitropous (antitropous) ovules, which are covered by a large obturator. The inner integument is thicker than the outer (equally thick in two species studied), and commonly both integuments form the micropyle. In mature ovules the vascular bundle commonly branches in the chalaza, with the branches extending to the base of the inner integument but not entering it. A nucellar cap and, less often, a nucellar beak is formed. Floral structure supports the close relationship of Picrodendraceae with Phyllanthaceae and Euphorbiaceae s.str. within Malpighiales, as suggested (but not yet strongly supported) by some recent published molecular analyses. These three families share a unique combination of characters, including (1) unisexual, apetalous trimerous flowers, (2) crassinucellar ovules with a nucellar beak, (3) a large obturator, and (4) explosive fruits with carunculate seeds.     

基于扫描电镜技术的天葵属(毛茛科)花器官发生研究

毛茛科天葵属为东亚特有类群,但其花器官的发生过程仍不清晰。该研究利用扫描电子显微镜观察了天葵［S. adoxoides (DC.) Makino］花器官的发生过程,以揭示毛茛科花形态的多样性和演化规律,为进一步探讨天葵属与近缘类群的亲缘关系提供发育形态学证据。结果表明：(1)天葵萼片、花瓣和雄蕊均为螺旋状发生,轮状排列;不育雄蕊的数目和位置不定,心皮轮状发生。(2)天葵萼片原基为宽阔的新月形,其他花器官为窄的半球形。(3)天葵花发育后期,花瓣有延迟发育现象,花瓣原基基部发育为浅囊状,心皮原基马蹄形对折,胚珠倒生、双珠被、具胎座附属物。(4)天葵属与耧斗菜属、尾囊草属的花发育性状存在相似性,支持分子系统学证据的三者近缘的观点;天葵属的花性状的特殊表现为：花直径较小,雄蕊、不育雄蕊和心皮数目较少,花器官没有形成明显的直列线,内珠被较长等。     

铁线莲属单性铁线莲组修订

对毛茛科铁线莲属Clematis L.的单性铁线莲组sect. Aspidanthera Spach s.l.进行了全面修订,确定此组共含72种和15变种,这些被归类于6个亚组中,其中包括首次描述的1系、5种和2变种,以及做出的2新等级。对单性铁线莲组的分类学简史和地理分布做了介绍。写出了组、亚组、系的形态特征和地理分布,分亚组检索表及各亚组的分种检索表;以及各种植物的形态描述、地理分布、生长环境等,并附有多幅插图。在研究了此组全部种类的标本之后,观察到此组几个重要形态特征的演化趋势：(1)萼片在数目上由     

灌木铁线莲（毛茛科）花器官的发生与发育

用扫描电子显微镜（SEM）对铁线莲属（Clematis L.）植物灌木铁线莲(C. fruticosa Turcz.)花的形态发生和发育过程进行了观察。灌木铁线莲花原基形成后,4枚萼片以交互对生的方式首先发生,呈轮状排列。最早的4枚雄蕊原基在4枚萼片交接的位置上近螺旋状发生,此后,随着雄蕊原基的向心发生和数目不断增多,其发生的螺旋状序列逐渐明显。雄蕊原基发生后,在花原基顶端,心皮原基沿着雄蕊原基的发生序列呈螺旋状发生。本文结果支持在原始被子植物花中螺旋状排列和轮状排列同时存在的观点。此外,本文也进一步证实了花萼与苞片的同源性。     

Androecial development and systematics inFlacourtiaceae s. l.

Androecial development of 13 species belonging to six tribes ofFlacourtiaceae has been investigated. While inScolopieae andFlacourtieae the stamens develop centrifugally, inErythrospermeae, Oncobeae andPangieae they are initiated in a centripetal sequence or a sequence that is neither distinctly centripetal nor centrifugal. The distribution of these developmental patterns coincides with the distribution of other characters (e.g. cyanogenic compounds, salicoid leaf teeth) and therefore supports a split of the family intoFlacourtiaceae s. str. (containing theScolopieae, Homalieae, Prockieae, Flacourtieae, Casearieae andBembicieae) andKiggelariaceae (withErythrospermeae, Oncobeae andPangieae) and is in accordance with results of recentrbcL studies.     

Chloroplast DNA variation inAnemone s. lato (Ranunculaceae)

Chloroplast DNA of seven species belonging toAnemone (sectt.Omalocarpus, Anemonidium, andAnemonanthea),Hepatica, andPulsatilla have been analyzed by restriction enzymes. According to the dendrogram constructed, the sections ofAnemone and the generaHepatica andPulsatilla seem to be evolutionary approximately equidistant to each others. This supports the concept that these groups should be treated on a similar taxonomic level, either as genera or subgenera.     

A revision of Clematis sect. Aspidanthera s.l. (Ranunculaceae)

1　BrieftaxonomichistoryInthefirstrevisionofthegenusClematisL .madebydeCandolle (1818) ,some 17unisexualspecieswererecognizedandallputinthelargeheterogeneoussectionFlammulaDC .,andtogetherwithotherbisexualspecieswereclassifiedintofivegroups:C .peruvianaDC .andC .caracasanaH .B .K .(=C .guadeloupaePers.)with 14speciesofsect.Clematis,sect.Brachiatae ,sect.Meclatis,andsect.Viornasubsect.Connataewereplacedintothefirstgroup ,whichwasdiag nosedas“Floribuspaniculatis,foliispinnatimbipinnatim…     

太原黄耆(豆科)花器官及胚珠发育研究

太原黄耆是新近发表的物种,分布于中国陕西和山西。该实验利用扫描电子显微镜对太原黄耆的花器官发生和发育过程进行观察研究。结果显示:(1)太原黄耆的各轮花器官都是从远轴端向近轴端单向连续发生,在不同轮之间存在花器官重叠发生的现象。(2)在花的发育过程中,出现2种共同原基,即初级共同原基和次级共同原基,由初级共同原基发育成对萼雄蕊原基和次级共同原基,再由次级共同原基发育成花瓣原基和对瓣雄蕊原基。(3)雄蕊管近轴端基部开口是在进化过程中产生的特殊结构,是一种对传粉者的适应机制,从而有利于传粉活动的进行。(4)胚珠为倒生胚珠,具有2层珠被,认为倒生胚珠是内外2层珠被共同作用的结果。     

Cytotaxonomical study ofSaxifraga seriesCeratophyllae s.l. (Saxifragaceae)

Chromosome numbers, mainly gametic, are given for 28 populations belonging to 13 species in ser.Ceratophyllae as circumscribed byWebb & Gornall. From a cytological point of view, we report or confirm the occurrence of aneuploidy in at least 8 of the 19 species recognized. This phenomenon, together with the technical difficulties inherent to the genus, is responsible for a number of incorrect or imprecise previous reports which are here questioned. Aneuploidy and the karyological instability behind it apparently reflect very active extant processes which might play an important role in the evolution of the group. Cytological and morphological data allow the recognition of four groups; one of them is likely to constitute a monophylectic group (ser.Ceratophyllae sensu stricto) but, the monophyly of the seriesCeratophyllae sensu lato is questioned.     

加查银莲花(毛茛科)的名实订正

通过标本检查, 发现毛茛科加查银莲花(Anemone jiachaensis W. T. Wang)与西藏银莲花(A. tibetica W. T. Wang)属于同一种植物, 故将前者处理为后者的异名。加查银莲花发表时被置于鹅掌草组[A. sect. Stolonifera (Ulbr.) Juz.], 但其花粉为三沟而非多沟, 与岩生银莲花亚组[A. subsect. Rupicolae (Tamura ex Chaudhary & Trifonova) Starod.]的岩生银莲花(A. rupicola Camb.)(西藏银莲花亦属于该亚组)的花粉类型一致, 而与鹅掌草组植物的多沟花粉明显不同, 从而进一步表明加查银莲花与西藏银莲花确为同一种植物而且应为岩生银莲花亚组的成员。     

The morphology and anatomy ofHydrastis (Ranunculales): Systematic reevaluation of the genus

Evidence from morphology and anatomy (including embryology), as well as from palynology, chemistry and cytology, indicates thatHydrastis is quite divergent from Ranunculaceae (in which the genus has been most often included) as well as from both Glaucidiaceae and Berberidaceae. Distinctive features ofHydrastis, which demarcate it from Ranunculaceae but which are sometimes shared by Berberidaceae, are: the unique mode of origin of the vascular supply to stamens and carpels; the micropyle being formed by both integuments; the xylem not V-shaped in cross section; scalariform vessel perforations present; haploid chromosome number 13; pollen tectum consisting of a compound layer of striae; leaf mesophyll not differentiated; the unique course of stem medullary bundles; D-galactose present. Its distinctive higher haploid chromosome number, as well as its many less-specialized character states (in floral structure, leaf anatomy, and xylem and vessel morphology), suggest thatHydrastis is a relictual primitive group which diverged early from a common ancestral stock of Ranunculaceae, Berberidaceae and probably of Circaeasteraceae; at least some of the features shared byHydrastis and one or another of the families concerned seem to be a heritage from their common ancestor. We propose a reestablishment of a monotypic family, Hydrastidaceae.     

Floral organogenesis of Helleborus thibetanus and Nigella damascena (Ranunculaceae) and its systematic significance

Floral organogenesis in Helleborus thibetanus and Nigella damascena was examined and compared using scanning electron microscopy and light microscopy, and the putative relationships of Helleborus and Nigella were analysed. H. thibetanus and N. damascena share some features of floral phyllotaxis and development of the sepals, petals, stamens and carpels, which are also found in other members of Ranunculaceae. However, they differ strongly in the number and degree of fusion of the carpels: in H. thibetanus, the two carpels are slightly united at the base, whereas, in N. damascena, the gynoecium is syncarpous and the five carpels are united throughout the ovary. Differences are also noted in petal development. The blade of the young petal of H. thibetanus develops two bulges which become connate and then fuse with the blade at the sides, developing more quickly than the blade and forming a tubular petal. In N. damascena, a single ridge is formed on the petal blade which develops into the smaller adaxial labium of the bilabiate petal, whereas the blade itself develops into the larger abaxial labium bearing two pseudonectaries. The outermost stamens are delayed in development in Helleborus, but not in Nigella. Although the results from our investigation are preliminary, differences in floral development characters suggest that Helleborus and Nigella may not be closely related and possibly support placement into separate tribes. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166 , 431–443.