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1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
The pistils of the Glorioseae (Gloriosa, Littonia, Sandersonia) are generally tricarpellate and alike. Virtually all have closed sutures at flowering; they have many ovules, some of which are barely bitegmic, with inner integuments often nearly fused with nucellar remnants; and there is usually but one compound septal bundle in the inner edge of a septum. In two species of Littonia , the compound septal bundle divided to form two simple septal bundles; but in many other plants it remained undivided, and in some it died out, still undivided, below the locular apex. Most of the placental and septal bundles are vascularized in large part by three alternate (compound septal) bundles at the base of the locules and sometimes by branches from the lateral bundles. Three large (compound) placental bundles are formed just below the lowermost ovular insertion, and each then divides in two to furnish ovular branches along their ascent. Occasional auxiliary placental bundles lie between the septal bundle and the placental bundles in the septum (Gloriosa, Sandersonia).  相似文献   

8.
Observations on the vascular floral anatomy, carpel morphology and floral biology ofHeloniopsis orientalis are presented. The lower flowering pedicel has six large bundles which lack an enclosing sclerenchymatous sheath. At mid-pedicel, branch bundles originate via radial divisions from each of these bundles. Subsequently, there is a vascular ring of 12 bundles below the receptacle. The six smaller bundles which are derived from alternate pedicel bundles eventually establish all of the ventral gynoecium supply. The six larger bundles supply the tepals, stamens and dorsal gynoecial vasculature. The simple dorsals do not branch or fuse in their vertical ascent. The ventral and placental supplies are far more complex. Fusion occurs between paired sets of the six smaller pedicel bundles along the septal radii and results in a submarginal laminal ventral network. An independent ventral plexus is formed in each septum and from each plexus two septal axials, of which the innermost has a reversed xylem-phloem disposition, and four placental bundles are derived. Two placental bundles are associated with each septal axial. Basally the septa are fused centrally, but are freed at mid-gymoecial height. The broadly tri-lobed, tri-carpellate gynoecium is depressed terminally where the erect, hollow style with its capitate stigma is attached. Dorsal grooves are present: the fruit is loculicidally dehiscent. There are no septal glands due to complete lateral fusion of the septal wings. Basally each of the six equal tepals has a saccate nectary. The similarity in vascular anatomy and carpel morphology of the AsianHeloniopsis and eastern North American endemic,Helonias bullata, justifies their position in the same tribe. Research and publication supported in part by the M. Graham Netting Research Fund through a grant from the Cordelia Scaife May Charitable Trust, the U. S.—Japan Cooperative Science Program Grant GF-41367, the Japan Society for the Promotion of Science, and Grant-in-Aid No. 934053 from the Ministry of Education, Japan.  相似文献   

9.
10.
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.  相似文献   

11.
The Tofieldieae consist of Narlhecium, Nietneria, Pleea , and Tofieldia. Although the three carpels of the pistil are generally coherent, their bases are separate for a short distance in some species of Tofieldia and in Pleea , where a septal nectary seems to be differentiated. These two genera are also alike in the extension of the chalaza as a filiform hook. The sutures are open at flowering only in some species of Tofieldia. Nietneria is distinguished by its inferior ovary and the alternate structure of the pistil. No raphide idioblasts were found in the carpels of any species.  相似文献   

12.
Most Helonieae have only slight septal indentations between the three carpels: in Xerophyllum deep septal clefts extend centripetally and completely enclosed, narrow septal pockets occur in Metanarthecium . Other unique generic features are found: tepallary-staminal nectarial glands in Heloniopsis , zygomorphy in Chionographis , and dioecism in Chamaelirium . The carpels are biovulate in Chionographis; there are two to several ovules per carpel in Xerophyllum; 8–12 ovules occur in the carpel of Chamaelirium; and numerous bitegmic ovules are borne in many longitudinal rows on enlarged placentae in Helonias, Heloniopsis, Metanarthecium , and Ypsilandra . Except for Metanarthecium , this last-named group of genera displays a near ring composed of 'accessory' placental bundles and a compound septal bundle (with normally oriented xylem and phloem) in cross-section at the inner edge of each septum. Ventral bundles occur in the other four genera.  相似文献   

13.
The floral vascular systems are compared among all six taxa of Saururaceae, including the two species of Gymnotheca which have not been studied previously. All are zygomorphic (dorsiventrally symmetrical), not radial as sometimes reported, in conformity with dorsiventral symmetry during organogenesis. Apocarpy in the two species of Saururus (with four carpels and six free stamens) is accompanied by a vascular system of four sympodia, each of which supplies a dorsal carpellary bundle, two ventral carpellary bundles, and one or two stamen traces. The level at which the ventral bundles diverge is the major difference in vasculature between the two species. The other four taxa are all syncarpous, and share some degree of stamen adnation and/or connation. The vascular systems also show varying degrees of fusion. The two species of Gymnotheca (with four carpels and six stamens) are very similar to each other; in both, the ventral traces of adjacent carpels fuse to form a placental bundle, which supplies the ovules and then splits into a pair of ventral strands. The flowers of Houttuynia cordata (with only three carpels and three adnate stamens) are sessile. Each flower is vascularized by three sympodia; the median adaxial sympodium is longer than the other two sympodia before it diverges to supply the adaxial organs. Three placental bundles also are formed in Houttuynia, but the three bundles differ in their origin. The median abaxial placental bundle diverges at the same level as the three sympodial bundles of the flower, while the other two lateral placental bundles diverge at a higher level from the median adaxial sympodium. Anemopsis californica, with an inferior ovary of three carpels, sunken in the inflorescence axis, and six stamens adnate to the carpels, has a vascular system very similar to that of Houttuynia cordata. The modular theory of floral evolution is criticized, on the bases of the known behavior of apical meristems and properties of vascular systems. The hypothesis is supported that saururaceous plants may represent a line of angiosperms which diverged very early.  相似文献   

14.
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.  相似文献   

15.
In comparing the floral vascular anatomy ofConvallaria majalis andC. keiskei a similar pattern of vasculature was shown. Both have pedicels with six (3 large +3 small) bundles which via radial division and fusion form the tepal, stamen and ovary traces. The outer tepal and outer stamen traces, the dorsals and placentals (i.e. ventral supply) arise from the larger three pedicel bundles, while the inner tepal and inner stamen traces and the septal axials arise from the smaller three. The dorsals, septal axials, and all of the stamen and tepal bundles are fusion products, while the placentals are free, though arising from compound bundles. The overy vasculature lacks both lateral peripherals and terminal cross-connections between the inner bundles and the outer dorsals. The placentation is only axile basally, since the three septa are freed at the mid-ovary level, and the resulting common, upper carpellary cavity is continuous with the hollow style. Normally four ovules are observed in each carpel, with the lower tier associated with the lower solid central axis, and the upper tier associated with the freed septa. The orientation of the ovules is varied (heterotropic). An internal system of stigmatoidal tissue is continuous from the base of each locule to the stigma, and involves micropylar associated obturators. Raphides characterize mature ovaries of both species, though both lack septal glands and septal grooves.  相似文献   

16.
The flower of Hydrocleis nymphoides consists of three sepals which arise in spiral succession, three simultaneously arising petals, numerous stamens and staminodia which arise in centrifugal order, and six carpels. A residual apex remains at maturity. The first-formed members of the androecium are stamens and the later-formed members are staminodia which develop below the stamens and which become outwardly displaced during expansion of the receptacle. The androecium is supplied by branching vascular trunk bundles. The carpels are completely open but the ventral margins are slightly conduplicately appressed basally. A single dorsal bundle provides the stigmatic area with vascular tissue, and a network of small placental bundles supplies the numerous laminar ovules. There are no clearly defined ventral bundles. It is suggested that Hydrocleis nymphoides is neither the most primitive nor the most advanced member of the family. A pattern of phylogenetic reduction in the androecium and receptacle is suggested for the entire family.  相似文献   

17.
18.
Patterns of proteins excreted during pollen germination, of germinating pollen and of the stylar and placental fluids excreted by cells along the pistil pathway of Gasteria verrucosa were analyzed by electrophoresis. The medium from germinating pollen contains several pollen exudate proteins as well as glycoproteins from the sticky pollen wall coating. No protein could be detected in the stigmatic exudate. The stylar fluid shows a protein pattern different from that of the placental fluid. The placental fluid contains some glycoproteins. After pollination, three pollen proteins begin to appear in the stylar fluid. Two of these pollen proteins remain present in the placental fluid. Some placental fluid proteins and glycoproteins are modified after pollination. The difference in protein patterns demonstrates the heterogeneity of proteins in the pollen tube pathway and suggests that proteins excreted by the pollen tube interact with other proteins in the pistil pathway, especially those in the placental fluid.  相似文献   

19.
The vascular system of the floret of Leersia is unified yet is segmented according to the appendages it serves. The rachilla at the floret base contains a collateral bundle related to the median trace of the lemma. The palea median trace joins the posterior of this bundle in the rachilla as the lemma laterals merge with the anterior. Although the stamen traces enter at the flanks of this rachilla bundle, they do not become fully incorporated into the system until near the floret base where the rachilla bundle, lemma laterals, and palea laterals converge. Traces from the lodicules attach to the anterior of the stamen traces. The base of the vascular system of the pistil, the pistil plexus, attaches tenuously by a bundle to the lower system between the entrance of the stamen traces. A bundle from each style attaches near the anterior of the pistil plexus below the level where the posterior of the pistil plexus rises, as the placental bundle, to merge with the ovule. Characteristics of the vascular system of Leersia, such as the relative discreteness of the staminal and stylar traces and the lack of both the anterior pistil bundle and the xylem discontinuity, are useful for delimiting the Oryzoideae from the Festucoideae.  相似文献   

20.
Observations presented here on floral vasculature in Alpinia hainanensis indicate that the labellum incorporates elements of five androecial members rather than two or three, as suggested by previous authors for Zngiberaceae flowers. The pedicel contains an outer ring and a central region of vascular bundles. Three carpellary dorsal bundles (CDs) and three alternatively arranged parietal bundles (PBs) separate from the central region successively. The remaining bundles of the central region run upwards and become the placental bundles to supply ovules. The placental bundles terminate between the top of the locular region and the base of the prolongation. The three PBs divides into about five strands respectively. Of which the outer strand enters into the petal being its midrib and the remaining strands move into the stamen adaxially being the vasculature of the functional stamen and the labellum abaxially being the lateral strands of the labellum. The three CDs divide into about five traces, of which the outer strand becomes the midrib of each sepal and the inner strand runs into the style. The remaining traces re‐unite, re‐divide again in the course up and the two adaxial sets of carpellary dorsals finally enter into the labellum being the marginal traces of it while the abaxial single strand enters into the labellum being its midrib. The two antero‐lateral glands receive small traces without lignified tube elements from the vascular plexus, which fonn in prolongation from both PBs and CDs and a few small strands in the ovary wall. There are no subulate appendages differentiated in the flower of Alpinia hainanensis. Hereby, the median of the sepals, both the marginal portions and the median of labellum, and the style have the same origin in vasculature from the CDs and so do the stamen, the lateral portions of labellum and the median of the petals from PBs. The labellum is supposed to represent three members of the outer androecial whorl by its two marginal portions and the median and two members of the inner whorl by its two lateral parts except the median.  相似文献   

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