Comparative morphology of the carpel in the Liliaceae: Colchiceae (Androcymbium)

The pistil of Androcymbium closely resembles that of Colchicum : it is tricarpellate usually, syncarpous and multiovulate, and the carpels of most species have open sutures and bitegmic ovules. The only species with closed carpellary sutures, A. dregei has monotegmic ovules. There are always three dorsal bundles and three compound septal bundles, which latter may bifurcate into simple septal bundles. Six placental bundles (two per carpel) are differentiated, either separately from the compound septal bundles or as lateral branches of them. A statistical evaluation of 47 species (6 genera) of the hemisyncarpous Wurmbaeoideae shows a significant tendency for bitegmic ovules and two simple septal bundles per septum to be associated with open sutures and for monotegmic ovules and no septal bundles to be associated with closed sutures.     

Comparative morphology of the carpel in the Liliaceae: Wurmbaeae

The two genera of Buxbaum's tribe Wurmbaeae, Anguillaria and Wurmbea , have multiovulate carpels. There are deep septal indentations between the carpels of Anguillaria , but the wings of adjoining carpels are fused to solid septa in most species of Wurmbea. In Anguillaria the carpels have open sutures or prominent commissural markings; in Wurmbea the carpels generally lack these characteristics, and some species have a vascularized, columella-like axis in the centre of the pistil. In both genera there are a dorsal bundle, lateral bundles, and two placental bundles in each carpel. At the inner edge of the septum there are one or two septal bundles in Anguillaria and one or none in Wurmbea. The ovules are monotegmic, the integument and funiculus being partly fused in Anguillaria and mostly fused in Wurmbea. An obturator is present in Anguillaria but absent from most species of Wurmbea.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE VII. POMOIDEAE: CHAENOMELES,CYDONIA, DOCYNIA

The multi-ovulate pomoids, Chaenomeles, Cydonia, and Docynia, all have closed sutures and extensive fusion between carpel and floral cup and between ovular and wing bundles. Although the ovules in Docynia are generally apotropic and few in number (4–7), the ovules in the other two genera are pleurotropic and numerous (15–48). A statistical treatment of the whole tribe of Pomoideae shows that in carpels with open sutures ovular and wing bundles definitely tend to be separate while in those with closed sutures these bundles tend to be fused. To a lesser degree carpels with open sutures also tend to have bitegmic ovules, separate carpels, and a lesser extent of fusion between carpel and floral cup, while carpels with closed sutures tend to have monotegmic ovules, united carpels, and a greater extent of fusion between carpel and floral cup.     

Comparative morphology of the carpel in the Liliaceae: Baeometra, Burchardia and Walleria

The pistils in Baeometra, Burchardia and Walleria ate tricarpellate, and their ovules are mostly bitegmic. Baeometra has free styles and deep septal invaginations between the carpels. Its pistil is innervated by three dorsal bundles, three compound septal bundles (each of which may divide into two simple septal bundles above), six placental bundles, and six adjoining auxiliary placental bundles. The pistil of Burchardia resembles that of Baeometra , except that there are six simple septal bundles throughout and no auxiliary placental bundles. In Walleria the wings of adjoining carpels are completely fused (except for rare septal glands); there is a single compound style; additional vascular tissue is present in the central axis of the pistil up to the lowermost ovules; the carpels are fused with the floral cup above the base of the locules; and raphide idioblasts are present. Walleria has six "ventral" bundles, each of which appears to be the fusion product of a placental bundle with a simple septal bundle. Tribal affinities of these genera are discussed.     

Comparative morphology of the carpel in the Liliaceae: Uvularieae

Three genera of the Uvularieae (Kreysigia, Schelhammera, Uvularia) have tricarpellate, syncarpous pistils. Ventral bundles (presumably the united simple septal and placental bundles of a carpellary wing) may be present in Kreysigia and Schelhammera. In Kreysigia the two presumptive ventral bundles from adjoining carpels are fused basipetally in each septum. The septal bundles of the other two genera are either simple (Schelhammera) or in part compound (united) below and simple (separate) above (Uvularia) , hence fused acropetally. In Uvularia , the dorsal bundle of the carpel and the median bundle of the tepal are uniquely tripartite and probably homologous. No raphides were found in the carpels of these genera.     

Comparative morphology of the carpel in the Liliaceae: Neodregeae

The structure of the carpel has been studied in flowers of the Neodregeae ( Dipidax and Neodregea ). Except in D. triquetra , which is syncarpous, the carpels are united below and free above. A dorsal bundle, two or more lateral bundles, and two placental bundles supply each multiovulate carpel. The six placental bundles of the tricarpellate pistil are united by twos in the lower part of the pistil, forming three opposite compound placental bundles in most species of Dipidax and three alternate bundles in D. triquetra and Neodregea : In the latter, an additional septal bundle continues upward as a branch from the compound placental bundle. Sutural openings are usually short and restricted to the top of the locule. All the Neodregeae have monotegmic ovules.     

Comparative morphology of the carpel in the Liliaceae: Colchiceae (Colchicum)

The pistil of Colchicum is syncarpous, the carpels having open sutures or well-marked commissures and many bitegmic ovules of variable orientation. Although the vascularization of the carpel is also variable, there are usually three dorsal bundles and three alternate, septal bundles at the base of the pistil, with occasionally some placental bundles at that level. More often the placental bundles, differentiating basipetally, appear to establish connections with the septal bundles higher up, at the lowermost ovular insertion level. The septal bundles divide in two more frequently in pistils in which the carpellary suture is open than in those in which it is closed.     

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.     

Comparative morphology of the carpel in the Liliaceae: Iphigenieae

The pistil in the flowers of the Iphigenieae (Camptorrhiza, Iphigenia, Omithoglossum) is usually tricarpellate. The carpels are coherent generally, with closed sutures and seemingly bitegmic ovules. Camptorrhiza differs from the others in having a single compound style. The pistils of most species of these genera have a common vascular structure: three dorsal bundles which run into the style(s), a number of lateral bundles, six placental bundles, and up to three compound septal bundles. The latter nine bundles usually differentiate from a central vascular plexus above the base of the locules. There may be fewer than three septal bundles in some specieS. When present, the septal bundles usually die out in the ovuliferous region, but in some cases they persist to the apex of the locules.     

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.     

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Patterns of angiospermy development before carpel sealing across living angiosperms: diversity,and morphological and systematic aspects

Almost all angiosperms are angiospermous, i.e. the ovules are enclosed in carpels at anthesis and during seed development, but angiospermy develops in different ways across angiosperms. The most common means of carpel closure is by a longitudinal ventral slit in carpels that are partly or completely free. In such carpels, the closure process commonly begins at midlength of the prospective longitudinal slit and then proceeds downward and upward. Closure by a transverse slit is rarer, but it is prominent in groups of the ANITA grade and in a few early branching monocots (some Alismatales) and some early branching eudicots (a few Ranunculaceae and Nelumbonaceae), in these eudicots combined with a more or less developed longitudinal slit. In all these cases the carpels have a single ovule in ventral median position. In ANITA lines with pluriovulate carpels, there is only a short longitudinal slit in the uniformly ascidiate carpels. In carpels with a unifacial style the closure area is narrow; this pattern is rare and scattered mainly in some wind‐pollinated monocots and eudicots. In most angiosperms the carpels become closed before the ovules are visible from the outside of the still incompletely closed carpels (early carpel closure). This is notably the case in the ANITA grade and magnoliids. Delayed carpel closure, with the ovules visible before the carpels are closed, is much rarer and is concentrated in a few monocots (mainly some Alismatales and some Poales) and a few eudicots (mainly a few Ranunculales and many Caryophyllales, and scattered in some other eudicots). A kind of delayed carpel closure (with the placenta visible before closure but mostly not the ovules) also occurs in syncarpous gynoecia with a free central placenta. Most gynoecia with a free central placenta occur in the superasterids. In such gynoecia the individual carpel tips are not differentiated but the opening in young gynoecia has the shape of a circular diaphragm. In this case, when ovary septa and free carpel tips are missing, the number of carpels is sometimes unclear (Primulaceae, Lentibulariaceae, some Santalaceae). Extremely ascidiate carpels are concentrated in the ANITA grade, a few magnoliids and some early branching monocots. Aspects of potential advantages of plicate vs. ascidiate carpels with regard to flexibility of pollen tube transmitting tract differentiation are discussed. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 556–591.     

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.     

Comparative morphology of the carpel in the Liliaceae: Veratreae

The genera of the Veratreae, a tribe of the Melanthioideae, have many features in common: there are usually many ovules, except for Amianthium (with 2 4), arranged in 2 -4 longitudinal placental rows per carpel; all are bitegmic, basipetal, and campylotropous. Of 37 species examined, only 2 have open sutures at the lowermost level of ovular insertion, but 13 species have holes in the centre of the pistil. These holes may represent possible stages in the evolutionary closure of previously open sutures. Most flowers were epigynous, only 11 being hypogynous-perigynous. The tribe as a whole is marked by the presence of 3 composite (heterologous) vascular bundles, composed of joined staminal and tepallary bundles alone and 3 composite bundles, as above, fused to a dorsal bundle. The bundles were united below the locular base in all genera except Schoenocaulon and Toxicoscordion. Two major kinds of central cylinder arrangement occurred at the level of the lowermost ovular insertion: either 6 inverted ventral bundles or 6 simple septal bundles, with normally arranged (or sometimes inverted) xylem and phloem centrifugally located and 6 simple placental bundles, with inverted xylem and phloem, at the centripetal end of the septum. Generally each septal bundle united with its nearest adjoining placental bundle about the mid-locular level.     

CONDUPLICATE AND SPECIALIZED CARPELS IN THE ALISMATALES

Carpel closure and stigmatic localization in the Alismatales have accompanied decreases in carpel size and numbers of ovules per carpel and increases in carpel numbers per flower. The most specialized carpels are uniovulate and indehiscent and occur acyclically in great numbers in each flower, with strong trends toward monoecism and even dioecism. The least specialized carpels in the order are open, multiovulate, and conduplicate, with poor differentiation of style and stigma. The Alismatales show a broad range from primitive to specialized gynoecial features.     

Morphology of the gynoecium and systematic position of the Ochnaceae

The gynoecium is syncarpous in all Ochnaceae. In the Ochnoideae carpels are peltate with a conventional cross-zone bearing one ovule, or, in Lophira , a very broad cross-zone with an horizontal ovular row. In Ochna and Brackenridgea , the style is gynobasic, each carpel develops transmitting tissue on its morphologically dorsal surface, and this tissue lines a canal or originates a solid inner strand in each carpel at style level. The style is tubular, with an inner cuticle, and compound, each component with its own transmitting tissue. In Ouratea the style is solid with a single compound transmitting strand. In Lophira and Elvasia the transmitting tissue seems to be developed by the morphologically ventral carpellary surfaces. Ovules are unitegmic with a bivalent integument.
In the Sauvagesioideae carpels are peltate, but with ovules above the cross-zones, on margins of the symplicate zone. In Euthemis , there is one ovule on each side of, and close to, each cross-zone. The single stylar canal is bounded by the morphologically dorsal carpellary surfaces. In Sauvagesia ovules occur on both sides of the cross-zones but most of them are above on carpel margins, as are all ovules of Cespedesia. The stylar canal of Sauvagesia is bounded by the ventral carpel surfaces, three strips of the outer surface passing inside at the sutures and developing into transmitting tissue. The stylar canal of Cespedesia is bounded by the dorsal carpel surfaces. The gynoecium of Wallacea has two epeltate carpels with a laminar placentation, the carpel margins being displaced on to the topographically ventral carpel surfaces with a row of ovules along each margin. Ovules are bitegmic.
The Ochnoideae, which shows relationships with the Rutaceae, Meliaceae, Simaroubaceae and Hippocastanaceae, is more advanced than the Sauvagesioideae, which clearly belongs in the Violales. The Ochnaceae is to be placed in the Violales.     

Floral development of Cardiopteris,with emphasis on gynoecial structure and ovular morphology

Cardiopteris is unique in the expanded Cardiopteridaceae for several distinctive features, including its gynoecial structure and ovular morphology. We studied the floral development of Cardiopteris to clarify floral morphology and document floral development. Cardiopteris has three carpel primordia, which are separate at their tips but congenitally fused at their bases. The synascidiate zone (the fused proximal part) develops into the unilocular ovary; the three discrete carpel apices diverge in development: the apex of the adaxial carpel differentiates into a style and stigma, while the apices of the two lateral-abaxial carpels elongate and develop into a fleshy appendage only after fertilization. The ovules are attached to the lateral-abaxial carpels. At anthesis, the ovules are ategmic and orthotropous without funicles (morphologically undifferentiated). Functional differentiation occurs in the three carpels of Cardiopteris: the adaxial one is the site of pollination, while the lateral-abaxial two produce ovules. The ategmic orthotropous ovule is unusual in Cardiopteridaceae and is an apomorphy of Cardiopteris.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE VI. POMOIDEAE: ERIOBOTRYA,HETEROMELES, PHOTINIA,POURTHIAEA, RAPHIOLEPIS,STRANVAESIA

The pomoid genera, Eriobotrya, Photinia, Pourthiaea, Raphiolepis, Stranvaesia, and Heteromeles, have compound inflorescences and biovulate carpels which become papery at maturity. The carpels of all of these except Heteromeles are fused with one another. There are open sutures in the carpels of Heteromeles, Photinia, Pourthiaea, and Raphiolepis, and in these four genera the extent of fusion of the ovular bundle with the wing bundle is related directly to the state of tegumentary fusion and to the extent of fusion of the carpel with the floral cup. In those species of Eriobotrya and Stranvaesia with closed sutures the integuments tend to be fused, as do the ovular and wing bundles, and the carpels are adnate with the floral cup for a considerable distance; in species with open sutures the integuments tend to be free, the ovular and wing bundles tend to be separate, and the extent of fusion of carpel with floral cup tends to be shorter. In genera with connate carpels the wing bundles of adjoining carpels may also be fused. The greatest extent of fusion occurs in Eriobotrya and Raphiolepis, in which there may also be attenuation and disappearance of the wing bundles above the region of ovular insertion and even reduction and disappearance of the carpellary margin.     

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.