Comparative anatomy and systematics of woody Saxifragaceae. Aphanopetalum Endl.

The floral and vegetative anatomy of the small Australian genus Aphanopetalum were studied. Wood is described for the first time and is characterized by predominantly solitary pores, scalariform vessel element perforation plates with low bar numbers, imperforate tracheary elements with distinctly bordered pits, sparse axial parenchyma, and a combination of homocellular and heterocellular rayS. Starch occurs in both axial and ray parenchyma of the wood. Stems possess unilacunar, one-trace nodes and the uncommon feature of an endodermis with well-defined Casparian stripS. Leaves have anomocytic stomata, a bifacial mesophyll and semicraspedodromous venation or a combination of semicraspedodromous and brochidodromous venation. The tetramerous flowers are apetalous or have minute petals. The compound, half-inferior gynoecium consists of essentially totally united carpels. The pattern of floral vascularization resembles different Saxifragaceae sensu lalo in that the compound sepal-plane and petal-plane traces give rise to staman bundles as well as sepal, petal, and carpel wall venation in their respective planes. The ventral ovarian bundles are fused into a single ventral complex that subdivides at the top of the ovary to form ventral bundles and to supply the one ovule in each locule. Vegetative and floral features provide compelling evidence to suggest that Aphanopetalum has its nearest relatives among the Saxifragaceae sensu lato rather than Cunoniaceae. The genus is probably best treated as forming its own subfamily (or family) among the saxifragaean alliance.     

STUDIES ON THE FLORAL ANATOMY OF THE CUNONIACEAE

Twenty-two genera representing sixty-two species of Cunoniaceae and Davidsonia were examined with respect to floral anatomy. Sepals are vascularized by three traces with the lateral traces of adjacent sepals united. Pancheria is unique for the family with species in which the sepals are vascularized by a single, undivided bundle. Petals, when present, and stamens, are uniformly one-trace structures. A general tendency exists within the family for the principal floral bundles to unite in various ways, with fusions evident between calyx, corolla, and androecial vascular supplies. Carpel number ranges from two to five and the gynoecium is generally surrounded by a prominent disc. Gynoecia of Ceratopetalum and Pullea are “half-inferior.” The number of ovules per carpel locule ranges from one to numerous. Ventral carpel sutures range from open to completely sealed at the level of placentation. Carpels of the apocarpous genus Spiraeanthemum (incl. Acsmithia) are vascularized by a dorsal bundle and either three or four bundles constituting the ovular and wing vasculation in the ventral position, a condition unlike other members of the family. Ovules are supplied by the median ventral bundle. More advanced bicarpellate gynoecia within the family are predominately vascularized by a dorsal and two ventral bundles although a variable number of additional lateral wall traces may be present. A major trend exists toward fusion of the ventral bundles of adjacent carpels in the ovary of both bicarpellate and multicarpellate plants. At the base of the styles the fused ventral strands separate and extend along with the dorsal carpellary bundles into styles of adjacent carpels. In Pullea the ventral bundles terminate within the ovules. The united ventral carpellary bundles in Aphanopetalum, Gillbeea, and Aistopetalum lie in the plane of the septa separating adjacent carpels. Ovules are vascularized by traces originating from the vascular cylinder at the base of the gynoecium or by traces branching from the ventral bundles. Ovular traces in each carpel are united, or remain as discrete bundles, prior to entering the placenta. Tannin and druses are common throughout all floral parts. Although floral anatomy generally supports the position of Cunoniaceae near Saxifragaceae and Davidsoniaceae, the evolutionary relationship of the Cunoniaceae to the Dilleniaceae is uncertain.     

FLORAL ANATOMY IN THE SAXIFRAGACEAE SENSU LATO. I. INTRODUCTION,PARNASSIOIDEAE AND BREXIOIDEAE

The floral morphology and anatomy of one representative of the Parnassioideae and two of the Brexioideae are described, and some of the recent literature dealing with the Saxifragaceae sensu lato is reviewed. Comparison of the floral structure in Parnassia to that typical of the Saxifragoideae, the subfamily constituting the Saxifragaceae sensu stricto and which, therefore, may be considered to show the basic saxifragaceous characteristics, reveals little similarity. Parnassia differs in pattern of both sepal and androecial vascularization, vascularization and degree of connation of the carpels, height in the gynoecium to which ventral bundles remain compound, possession of nectariferous staminodia, and the absence of epidermal appendages. Brexia and Ixerba (both of the Brexioideae) are strikingly dissimilar in floral structure and probably should be dissociated. While the position of Ixerba is problematical, it shares more floral characters with the Escallonioideae than with either Brexia or the Saxifragoideae and is better associated with that taxon. In both Parnassia and Brexia the vascular pattern suggests derivation of the androecium from a fascicled condition: the vascular supply of each filament consists of a cylinder of closely associated collateral bundles, and each staminodial set receives a single vascular complex which subsequently divides into as many vascular strands as there are staminodia in the set.     

SYSTEMATIC ANATOMY OF THE FLOWER AND FRUIT OF COROKIA

Corokia, a genus of shrubs of New Zealand, eastern Australia, and certain Pacific islands, was first placed in Rhamnaceae, later in Cornaceae, and most recently next to Argophyllum, subfamily Escallonioideae, in Engler's monograph of the Saxifragaceae. Most manuals still list Corokia under Cornaceae from which it is readily excluded by several characters, including pluricellular T-shaped trichomes, ligulate petals, vascular bundles running longitudinally through the center of the inferior gynoecium, histology and germination of the woody endocarp, and a conspicuous subepidermal layer of tannin-containing cells. Corokia collenettei, endemic to the isolated island Rapa, retains the most primitive floral characters of the genus. Anatomical comparison of Corokia flowers with flowers of Argophyllum shows similarities that probably indicate affinity, but the relation of these two genera to others in Engler's subfamily Escallonioideae is unclear. Engler's inclusion of Berenice and Carpodetus with Corokia and Argophyllum in a tribe Argophylleae seems especially artificial.     

ANATOMY OF THE GYNOECIUM IN TWO SPECIES OF BAKERIDESIA (MALVACEAE)

Structure of the gynoecium is described in two species of Bakeridesia, subgenus Bakeridesia (Malvaceae, tribe Malveae). The dorsal wall of each carpel bears a winglike projection with a marginal pair of pubescent, bluntly dentate wings. The projection arises as a single, solid ridge of tissue after the ovules are initiated and after the ventral carpellary margins are fused with the receptacle. Two multiseriate layers of fiber-sclereids line each locule and continue into the winglike projection where they are separated by parenchyma. Gynoecial vascularization is described in detail. The richly vascularized carpels are supplied by five traces: a median dorsal trace, which bifurcates into two dorsal bundles; two lateral traces; and two ventral traces. Adjacent ventral traces, lateral traces, and septal bundles are fused—i.e., they are held in common by neighboring carpels. The presence of lateral carpellary traces may be a primitive character in the tribe Malveae.     

ONTOGENY AND ANATOMY OF THE FLOWER OF LIMNOCHARIS FLAVA (BUTOMACEAE)

The flowers of Limnocharis flava (L.) Buch. are borne in an indeterminate umbel and each consists of three sepals, three yellow petals, and about 18 carpels surrounded by numerous stamens and staminodia. The androecium is centrifugally developed, and the last-formed members are staminodial; it is supplied by branching vascular systems. Carpels arise almost simultaneously, and a prominent residual floral apex remains. The carpels are partially conduplicately closed and are also primitive in possessing laminar placentation and in lacking differentiation of a style. The gynoecium is essentially apocarpous, but there are slight fusions of adjacent carpels near their ventral margins where they are attached to the receptacle. It is suggested that the Limnocharis flower is the most primitive in the family.     

THE GYNOECIAL DEVELOPMENT AND SYSTEMATIC POSITION OF ALLAMANDA (APOCYNACEAE)

Allamanda exhibits an unusual type of gynoecial development in which the two carpels are free at initiation, but fuse completely during development, resulting in a unilocular ovary with parietal placentation at maturity. Whereas the majority of the Apocynaceae are characterized by an advanced type of gynoecium that is secondarily apocarpous, in Allamanda gynoecial evolution has proceeded one step further to secondary syncarpy. This condition is not known to occur in any other genus in the Apocynaceae and provides further evidence of the isolated position of Allamanda within the family.     

Divisestylus gen. nov. (aff. Iteaceae), a fossil saxifrage from the Late Cretaceous of New Jersey, USA

Fossilized flowers and fruits from the Upper Cretaceous (Turonian, ca. 90 million years [my] before present) Raritan Formation of New Jersey are described as the new genus Divisestylus with two species, D. brevistamineus and D. longistamineus. The fossils are fusainized and three-dimensionally preserved. Morphological characteristics suggest affinities with extant Saxifragaceae and Iteaceae, two closely related families in Saxifragales. Similarities include a pentamerous perianth, calyx fused below into a hypanthium with free sepal lobes above, haplostemonous androecium with stamens situated opposite the calyx lobes, inferior ovary, bicarpellate gynoecium, numerous ovules on axile placentas, conspicuous intrastaminal nectary ring, and capsulate fruit opening apically. The unique fusion of the gynoecium, with carpels and stigmas fused but styles free, indicates closer affinities with extant Iteaceae, whereas other characters, such as basifixed anthers in D. brevistamineus, tricolpate and striate pollen grains, and anomocytic stomata, indicate closer affinities to Saxifragaceae. Cladistic analyses utilizing molecular data from a previously published analysis and morphological data as well as morphological data alone demonstrate the fossils share a more recent common ancestor with Iteaceae than Saxifragaceae, thereby making Divisestylus the oldest fossils known with clear affinities to Iteaceae.     

The floral development and floral anatomy ofChrysosplenium alternifolium, an unusal member of the Saxifragaceae

The floral development and anatomy ofChrysosplenium alternifolium were studied with the scanning electron microscope and light microscope to understand the initiation sequence of the floral organs and the morphology of the flower, and to find suitable floral characters to interpret the systematic position of the genus within the Saxifragaceae. The tetramerous flower shows a highly variable initiation sequence. The median sepals and first stamens arise in a paired sequence resembling a dimerous arrangement, but the first sepal and stamen arise on the side opposite to the bract. Transversal sepals and stamens emerge sequentially, as one side often precedes the other; sepals and stamens occasionally arise on common primordia. Initiation of the gynoecium is more constant with two median carpel primordia arising on a sunken floral apex. Several flowers were found to be pentamerous with a 2/5 initiation sequence. Flowers were invariably found to be apetalous without traces of petals in primordial stages; this condition is interpreted as an apomorphy. It is postulated that the development of a broad gynoecial nectary is responsible for the occurrence of an obdiplostemonous androecium. The gynoecium shows a number of anatomical particularities not observed in other Saxifragaceae. The presence and distribution of colleters is discussed.     

滇鼠刺花的形态发生（鼠刺科）

在扫描电镜下 ,观察了滇鼠刺 (IteayunnanensisFranch .)花的形态发生。花 3朵一束 ,排成总状花序。花器官为轮状结构 ,向心发生 ;花萼以 2 /5螺旋式相继发生 ,5个花瓣原基几乎同步地在花萼内侧与其互生的位置发生。雄蕊单轮对萼。当雄蕊发生后 ,花顶中心的分生组织开始凹陷 ,成为浅锅状 ;在其周围出现一个环状的分生组织 ,随之 ,2心皮原基产生 ,进而发育为马蹄形。初期的心皮相互分离 ,随着进一步发育 ,心皮内卷 ,彼此靠近、紧贴 ,逐渐于腹面合生 ,形成 2室的中轴胎座 ;花柱的腹维管束通过薄壁组织连通 ;花期柱头融合 ,因此该种为合生心皮。对鼠刺属 (Itea)及相关类群花发育性状和花结构进行了比较 ,支持把鼠刺属提升为鼠刺科 (Iteaceae)的观点。     

FLORAL ANATOMY IN THE SAXIFRAGACEAE SENSU LATO. II. SAXIFRAGOIDEAE AND ITEOIDEAE

The floral anatomy and morphology of 26 species from the Saxifragoideae and three from the Iteoideae are described and compared. The flowers of the Saxifragoideae are predominantly actinomorphic, partially epigynous and/or perigynous, and pentamerous, with two carpels which bear numerous ovules. There is usually some degree of independence between carpels, and the normally separate styles possess both a canal and transmitting tissue. Generally, staminodia are absent and nectariferous tissue, which is not vascularized, is present. The subfamily is characterized by large multicellular trichomes with globular, often glandular, heads. Placentation may be parietal, axile, or transitional between the two; parietal appears to be a derived condition in the subfamily. The vascular cylinder in the pedicel generally consists of several to many discrete bundles from which diverge ten compound traces at the base of the receptacle, leaving an inner cylinder of vascular strands that coalesce at a higher level into either as many ventral bundles as carpels or twice that number. In the former case, each ventral bundle consists of one-half of the vascular supply to each adjacent carpel and separates into individual ventral strands in the distal half of the ovary. The ventral bundles provide vascular traces to the ovules and, along with the dorsals, extend up the style to the stigma. Each trace diverging in a sepal plane typically supplies one or more carpel-wall bundles, a median sepal bundle, and a stamen bundle. Each petal-plane trace usually provides one or more carpel-wall bundles, a lateral trace to each adjacent sepal, a petal bundle and, in flowers with ten stamens, a stamen bundle. Dorsal carpel bundles are usually recognizable and may originate from traces in either perianth plane. While the position of Ribes remains problematical, its floral structure does not easily exclude it from the Saxifragoideae. Floral structure in the Iteoideae is remarkably similar to that in the Saxifragoideae, the main differences being a lesser degree of independence between carpels, generally narrower placentae with somewhat fewer ovules, and the presence of only unicellular, acutely pointed epidermal hairs as opposed to the relatively complex, multicellular trichomes prevalent in the Saxifragoideae.     

Floral morphology and structure of Phyllonoma (Phyllonomaceae): systematic and evolutionary implications

Phyllonoma, a small tree genus of four species distributed from Mexico to Peru, has been placed in various families (mainly in Saxifragaceae), but now, based on molecular evidence, is placed in a distinct family Phyllonomaceae in Aquifoliales. To better understand the morphological relationships of the genus and family, I studied its floral morphology, anatomy, and vasculature using P. tenuidens. Most of the external and internal floral characteristics were described more than 120 years ago. Although some of them were confirmed, some were substantially revised, mainly those concerning the gynoecial structure. Flowers are small and basically pentamerous, consisting of five sepals, five petals, five stamens, and a gynoecium composed of two carpels usually in transversal position. Comparisons with other Aquifoliales show that Phyllonomaceae share the inferior ovary, epiphyllous inflorescence and epigynous disc nectary with East-Asian Helwingiaceae (Helwingia only), but clearly differ from Helwingiaceae in having glandular trichomes on the sepal margins and a bicarpellate, unilocular gynoecium bearing many ovules on the parietal placentae. Evidence from floral morphology and structure supports the distinctness of Phyllonomaceae and its sister-group relationship with Helwingiaceae. Its floral characteristics suggest that Phyllonomaceae have evolved by adapting to distinct biological habitats in relation to pollination and seed dispersal.     

THE PALM GYNOECIUM

The morphology, anatomy, and histology of the gynoecia at or close to anthesis are described for 20 genera of palms selected to represent different taxonomic alliances and to include major gynoecial types within the family. Palms may have 1–10 carpels, but most have three. Fifteen genera, including 14 coryphoid palms and the monotypic Nypa fruticans, are apocarpous and the remainder, approximately 190, are syncarpous. Fusion of carpels in some gynoecia begins in the base, in others in the styles. Pseudomonomerous pistils occur in several different alliances: the ovarian parts of two carpels are reduced but three usually equal and functional styles and stigmas are present. The carpel is often follicular in shape with the ventral suture open or, more frequently, partially or completely closed. The carpel may be stipitate or sessile and usually has a conduplicate laminar part. Most carpels are spirally and laterally inserted on the receptacle, but the carpel in some unicarpellate genera (e.g., Thrinax) appears terminal. Stipes, ovarian parts, styles, and stigmas vary in structure and development. Septal nectaries which differ in size, in the presence or absence of specialized canals, and in position, characterize all genera of some groups but only some genera of others. Diverse vascular configurations in the bases of gynoecia vary according to the extent of the floral axis, the development of carpellary stipes, and the connation of the carpels and their adnation to the tip of the floral axis. Four types of carpellary vascular systems are present in the genera described: (1) most palm carpels have three major traces consisting of a dorsal bundle and two ventral bundles, and they may also have up to four pairs of lateral bundles or occasionally more; (2) in certain cocosoid palms no ventral bundles can be distinguished, but a dorsal bundle, many parallel lateral bundles, and a row of immature ventral strands vascularize each carpel; (3) carpels of Phytelephas have a dorsal bundle, two pairs of major lateral bundles and about four pairs of shorter lateral bundles, with no identifiable ventral bundles; (4) carpels of Nypa have many dichotomously branched bundles but none that are recognizable as dorsal, ventral, or lateral strands. Additional peripheral bundles or systems may be present in each of the above types. Ovules are supplied by 1–15 bundles. These are derived either from the carpellary stele; from ventral bundles only; from ventral, lateral, and dorsal bundles; or from a combination of these origins. Certain areas of the gynoecia or certain parts of dorsal carpellary walls in some genera are much less mature at anthesis than surrounding tissues. Implications for floral biology and relationships within the palms and of palms to other groups are discussed.     

The Carpel of Moringa

The gynoecium of Moringa is tricarpellary, syncarpous and unilocularwith parietal placentation. The three carpel primordia ariseindependently but soon become connected resulting in an annularstructure which develops into the tubular gynoecium. The gynoeciumis supplied with three dorsal and three marginal bundles. Thelatter represent the fusion product of the marginal bundlesof adjacent carpels and each splits into three in the ovarywall. The ovules receive their vascular supply from a commonbundle, which branches from the dorsal trace of the carpel atthe base of the ovary. The derivation of the gynoecium fromconduplicate carpels is postulated. Moringa oleifera, carpel morphology, conduplicate carpel, carpel ontogeny     

Gynoecium structure and extra-gynoecial pollen-tube growth in an apocarpous species, <Emphasis Type="Italic">Sagittaria trifolia</Emphasis> (Alismataceae)

Apocarpy is regarded as an original feature obtained during the evolution of angiosperms. Compared with syncarpous plants, apocarpous plants have some adaptive disadvantages in apocarpous plants, for example, the number of offspring is lower under conditions of uneven pollen-tube distribution. However, in some apocarpous species, extra-gynoecial pollen-tube growth (EGPG) may remedy this disadvantage. We conducted micro-observations and field studies of Sagittaria trifolia, to investigate the gynoecium structure and the pathway of pollen-tube growth in the entire gynoecium. In a single-carpel pollination experiment, we found that the extra-gynoecial pollen tubes from a carpel of S. trifolia were able to fertilize approximately 13 carpels. Simulated EGPG in the entire gynoecium of S. trifolia revealed that its effect on the seed set could be divided into two stages: stage of low/high-level stigmas pollination, in which the cutoff point was about 0.1. The seed set would be markedly improved during the low-level stigmas pollination stage by EGPG when the maximum distance of extra-gynoecial pollen tubes could span three carpels, as in the present experiment. Our simulation also showed that the high pollen load could enhance the effect of EGPG on the seed set, and if the number of germinating pollen is triple the carpel number in the gynoecium, a 100% seed set rate would be obtained when approximately 50% of the stigmas are pollinated.     

Morphological studies on the genusClematis linn

In four-sepaled flowers ofClematis the sepal is supplied by three main traces. The basic pattern of the vascular supply to sepals is found inC. alpina var.ochotensis which invariably has six-bundled pedicels. It is as follows: the median traces to the first pair of opposite sepals, as well as all the lateral traces, arise directly from pedicel bundles, while those to the second pair are formed secondarily, after fusion and subsequent division of two adjacent pedicel bundles. As to the manner of origin of the median traces, the pattern is similar to that of the vascular supply to foliage leaves. This gives further evidence for the generally accepted view that the sepals ofClematis, like foliage leaves, are decussately arranged. In most other species such asC. apiifolia, C. stans, etc. the number of pedicel bundles tends to be reduced from six to four so as to coincide with that of the sepals, so patterns are much simplified and specialized: all the traces arise directly from pedicel bundles. InC. japonica an iconsistent pattern is observed, since the number of pedicel bundles from which sepal traces arise is much higher and varied.     

Female flower and fruit anatomy of Tetroncium magellanicum: implications for gynoecium evolution in the early divergent monocot order Alismatales

Female flower and fruit anatomy, including vasculature, are studied for the first time in Tetroncium (Juncaginaceae: Alismatales). Other members of Juncaginaceae (and the relatively close Maundiaceae) possess a peculiar type of gynoecium with pronounced carpel fusion via the floral centre. Their carpels are supplied by individual vascular traces and can be interpreted either as synascidiate (if viewed as horizontally inserted) or free and plicate (if viewed as obliquely inserted on an elongated receptacle). In Tetroncium, the gynoecium is tetracarpellate and clearly has a well‐developed synascidiate zone with septa formed by united flanks of adjacent carpels. The gynoecium of Tetroncium is supplied by a common ring of vascular tissue that splits into dorsal and heterocarpellary ventral (synventral) bundles, a condition that can be expected in a typical syncarpous gynoecium. The fruit is indehiscent and contains one or two seeds. The syncarpy of Tetroncium is of functional significance for fruit formation, as it allows the thin septa to be distorted, thus providing more space for the developing seed(s). The occurrence of typical syncarpy in Tetroncium provides further evidence for the highly homoplastic evolution of gynoecium characters in the early‐divergent monocot order Alismatales. Either the similarity between gynoecia of Maundiaceae and Triglochin (Juncaginaceae) is due to parallel evolution or the syncarpy of Tetroncium should be viewed as secondarily derived. In the latter scenario, fusion via the floral centre is probably a synapomorphy of core Alismatales (Helobiae) and more typical syncarpy evolved independently in several lineages, such as Scheuchzeria, Tetroncium and Butomus/Hydrocharitaceae. In total, Tetroncium differs from other Juncaginaceae in 13 structural characters, including ensiform leaves that are similar to those of Tofieldiaceae. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 712–724.     

Floral ontogeny of Ruteae (Rutaceae) and its systematic implications

Floral development was investigated in Ruta graveolens and Psilopeganum sinense, representing two genera in the tribe Ruteae. Special attention was paid to the sequence of initiation of organ whorls in the androecium and gynoecium. The antepetalous stamens arise at the same level as the antesepalous stamens in both species. The carpels are antepetalous in both taxa, indicating the androecium in both genera is obdiplostemonous. Compared with floral ontogeny of the ancestral genus Phellodendron (Toddalioideae), the obdiplostemonous androecium is a derived condition. The floral apex in P. sinense is quadrangular before initiation of the two carpels. Additionally, there are four dorsal and four ventral traces in the ovary. Integrated morphological and anatomical evidence indicates that the bicarpellate gynoecium in Psilopeganum most likely evolved from a tetracarpellate ancestor. Considering the similarities in morphological, geographical and chromosomal features, the ancestor may be Ruta‐like. Further molecular phylogenetic and genetic studies are needed to verify this assumption.     

商陆科植物的子房结构观察

商陆科植物几种雌蕊类型的发育和结构进行了观察,结果表明,商陆科植物的心皮发生后,首先形成一个开放的心皮,开口在心皮的腹侧,开口的封闭都是由心皮边缘的：表皮细胞及表皮下的几层细胞的分裂和生长完成。单心皮雌蕊在子房封闭后不留任何痕迹,而多心皮雌蕊的心皮封闭后留下明显的封闭线。封闭线由栅栏组织状组织构成。栅栏组织状组织一直延伸到珠柄,在珠柄基部形成毛刷状结构。离生心皮的隔在子房的生长过程中生长很少,心皮的大部分是分离的;合生心皮的隔在心皮的生长过程中与心皮同步生长,心皮始终是合生的。成熟子房的结构基本相同,子房壁为薄壁细胞,除表皮以外其他细胞均无太：大区别。在子房外侧壁中均匀地分布有3～5个维管束,隔中有一个维管束。胚珠生于子房的基部腹侧。     

Cunoniaceae in the Cretaceous of Europe: Evidence from Fossil Flowers

Fossil flowers of the Cunoniaceae from Late Cretaceous sedimentsof southern Sweden are described in detail. The flowers aresmall, bisexual, actinomorphic, tetramerous with broadly attachedvalvate sepals; they have narrowly attached petals; eight stamensin two whorls; a massive, lobed nectary; a semi-inferior, syncarpousgynoecium with axile placentation; numerous ovules; separatestyles; and peltate, probably secretory, trichomes. They sharemany features with extant representatives of both the Cunoniaceaeand Anisophylleaceae. However, the gynoecium structure in particularindicates a closer relationship to the Cunoniaceae. The floralcharacters are not specific for any extant genus of the familyand therefore a new genus and species, Platydiscus peltatusgen. et sp. nov., is formally described. This is the first recordof cunoniaceous floral structures from the Northern Hemisphereand the oldest record of Cunoniaceae flowers worldwide. Copyright2001 Annals of Botany Company Anisophylleaceae, Cunoniaceae, fossil flowers, Late Cretaceous, Oxalidales, Platydiscus peltatus gen. et sp. nov., Santonian-Campanian, southern Sweden