The connective base and filament of Acicarpha tribuloides (Calyceraceae)

The structural and autofluorescent properties of the staminal connective base of Acicarpha tribuloides (Juss.) clearly distinguish it from the filament. The abaxial and lateral connective base epidermal walls have secondary thickenings and are autofluorescent. The filament walls lack these characteristics. Also, the wrinkled or bulbous cuticular surface of the filament epidermis is distinct from that of the connective base which is smooth and relatively flat. In regard to these characteristics, A. tribuloides strongly resembles Cirsium horridulum (Michx.), a species in the Asteraceae. A. tribuloides differs from C. horridulum in that the cytoplasm in both the connective base and the free filament cells becomes severely disorganized and some of the walls collapse during anthesis in the former species. Thus, while the staminal tissues of these two species have some similar structural and biochemical features, they have significantly different functional roles. The presence of a connective base in the Calyceraceae significantly broadens the known range of this feature, and can be used as evidence to support the hypothesis that this feature is plesiomorphic within the Asteraceae.     

A survey of autofluorescent patterns in the staminal connective base epidermis in 60 species of Asteraceae

All 60 Asteraceae species sampled, i.e., two species of Bamadesioideae, 21 species in six tribes in Cichorioideae, and 37 species in nine tribes of Asteroideae, show specific patterns of autofluorescence in abaxial connective base epidermal cells. Two species of Cichorioideae and 15 species of Asteroideae have autofluorescence in adaxial epidermal cells of the connective base. Several taxonomically useful features of the connective base are identified; they include shapes of autofluorescent cells, patterns of distribution of cells with autofluorescent walls, and patterns of distribution of autofluorescence in walls. Cellular features of many species coincide with recognized generic, tribal, and subtribal classifications. The results extend Cassini's characterization of the article anthérifere and indicate that the variable features of the connective bases of stamens of Asteraceae could contribute to phylogenetic understanding.     

Occurrence and evolutionary significance of RESISTANT CELL WALLS IN CHAROPHYTES AND BRYOPHYTES

A survey of charophycean green algal and bryophyte taxa revealed the frequent occurrence of vegetative cell walls that were characterized by a specific form of autofluorescence and resistance to high temperature acid treatment (acetolysis). The time of production and the location of resistant, autofluorescent cell walls varied among charophyte and bryophyte taxa in patterns that suggest that bryophytes inherited the capacity to produce such walls from charophyte ancestors. A number of charophytes produced resistant walls in response to desiccation stress, suggesting an evolutionarily early adaptive response. Coleochaete was unique among charophytes, but similar to all bryophytes tested in that sexual reproduction induced autofluorescence in cell walls of well-hydrated tissues at the placental junction. Maternal tissues in apical portions of the pseudoseta bearing Sphagnum sporophytes were characterized by autofluorescent, acetolysis-resistant cell walls similar to those observed in maternal cells adjacent to Coleochaete zygotes. These observations suggest that cell–cell stimulus–response interactions regulate deposition of autofluorescent compounds in placental cell walls, and that this characteristic may have been shared by the earliest embryophytes and their charophyte ancestors. Various bryophytes deposit autofluorescent, acid-resistant compounds at other adaptively significant sites including sporangial epidermis, spiral thickenings of elaters, rhizoids, and leaves in the special case of Sphagnum moss. Sphagnum and liverwort sporangial epidermis, which had been subjected to acetolysis or strong acid procedures commonly used to release microfossils from rock matrices, resembled published photographs of Ordovician–Devonian microfossils consisting of cellular scraps that have been attributed to earliest land plants. Our work suggests that at least some of these fossils, previously thought to represent “dispersed cuticles,” could be reinterpreted as earliest known remains of plant sporophytic tissues, and that they may be homologous with resistant sporangial epidermis of modern bryophytes. In general, the patterns of occurrence of resistant, autofluorescent cell walls in charophytes and bryophytes suggest repeated exaptation. Regulation of deposition appears to have been modified through time, so that resistant wall compounds have had a sequence of functions: desiccation resistance and/or microbial resistance in lower charophytes, a role in embryogenesis in Coleochaete and embryophytes, and finally, decay resistance in innovative structures that characterize bryophytes, such as rhizoids, sporangial epidermis, and elaters.     

A new method for measurement of annual growth rings in cork by means of autofluorescence

A new method for measuring annual growth rings in cork has been developed. It is based on the fact that excitation of Quercus suber L. cork cross-sectional planes with UV light and also with blue light results in enhanced autofluorescence at the growth ring borders. This distinct autofluorescence band is located in the cork produced at the end of the vegetation period, with its smaller cells and thicker cell walls. The enhanced autofluorescence of polyphenolics mainly results from a very thick suberin layer in the walls of the small late cork cells. The gradient in autofluorescence from late cork to first early cork is steep. The best visibility of cork annual rings was found under the epifluorescence microscope in 60 μm thick microtome cork cross sections. For fast screening of high sample numbers scanning the blue-excited (473 nm) fluorescence of water wetted polished cross-sectional surfaces of cork pieces with a laser-equipped fluorescence image analyzer was most suitable. Evaluation of visibility of cork rings showed a clear improvement in comparison with reflected light image analysis; thus data obtained with this new autofluorescence scanning method are excellent for modeling the yearly growth increment of cork.     

Fuchsin fluorescence and autofluorescence in Cryptosporidium, Isospora and Cyclospora oocysts

Cryptosporidium parvum and Isospora belli oocysts stained with carbol–fuchsin, as in a modified Ziehl–Neelsen technique, fluoresce bright red under green light (546 nm). Cryptosporidium oocysts tend to fluoresce more brightly the less intensely stained they appear under transmitted light; this is not the case with Isospora. Fuchsin-stained Cyclospora cayetanensis oocysts fluoresce rather dimly, but those not taking the dye retain their typical autofluorescence. Cryptosporidium and Isospora oocysts are also autofluorescent, appearing violet under u.v. light (365 nm), and green under violet (405 nm) and blue–violet light (436 nm). Their autofluorescence does not survive the staining procedure.     

Autofluorescent characteristics of Candidatus Brocadia fulgida and the consequences for FISH and microscopic detection

An enrichment culture of Candidatus Brocadia fulgida was identified by three independent methods: analysis of autofluorescence using different microscope filter blocks and a fluorescence spectrometer, fluorescence in situ hybridization (FISH) with anammox-specific probes and partial sequencing of the 16S rDNA, hydrazine synthase hzsA and hydrazine oxidoreductase hzo. The filter block BV-2A (400–440, 470 LP, Nikon) was suitable for preliminary detection of Ca. B. fulgida. An excitation-emission matrix revealed three pairs of excitation-emission maxima: 288–330 nm, 288–478 nm and 417–478 nm. Several autofluorescent cell clusters could not be stained with DAPI or by FISH, suggesting empty but intact cells (ghost cells) or inhibited permeability. Successful staining of autofluorescent cells with the FISH probes Ban162 and Bfu613, even at higher formamide concentrations, suggested insufficient specificity of Ban162. Under certain conditions, Ca. B. fulgida lost its autofluorescence, which reduced the reliability of autofluorescence for identification and detection. Non-fluorescent Ca. Brocadia cells could not be stained with Ban162, but with Bfu613 at higher formamide concentrations, suggesting a dependency between both parameters. The phylogenetic analysis showed only good taxonomical clustering of the 16S rDNA and hzsA. In conclusion, careful consideration of autofluorescent characteristics is recommended when analysing and presenting FISH observations of Ca. B. fulgida to avoid misinterpretations and misidentifications.     

Lodicule Function and Filament Extension in the Grasses: Potassium Ion Movement and Tissue Specialization

Flowering in the grasses has been the subject of a great deal of previous research, yet much remains to be learned concerning the role of environmental and endogenous factors in controlling the actual events of anthesis. The objective of this study has been to investigate further two key processes, namely lodicule function and stamen extension.The lodicules are the two diminutive bodies lying between the lemma and the ovary base in the grass floret which, by expanding rapidly at the time of anthesis, lever away the rigid lemma allowing anthers and stigmas to emerge. Expansion results from the swelling of a cushion of tissue at the base of each lodicule. We show that this is driven by the influx of water associated with the accumulation of K⁺in specialized distensible cells of the basal cushion. The stamen filaments normally elongate synchronously with the enlarging lodicules, again with the passage of K⁺into the extending cells. The walls of distensible cells of the lodicule bear lattice-like cellulosic thickenings with transverse bars in an outer layer and longitudinal bars in an inner, a basket-like disposition allowing rapid expansion while preserving the integrity of the protoplast. The microfibrils in the walls of the cylindrical filament cells are disposed helically, constraining expansion to the longitudinal axis. The principal extraneous factors initiating lodicule function in mature florets of rye are mechanical disturbance and light. In the field radiant heat is unlikely to be a dominant factor. In a customarily cleistogamous cultivar of wheat, sporadic florets open chasmogamously in intense light, both lodicules and stamen filaments enlarging. In cleistogamous flowers in the same inflorescence the lodicules fail to enlarge while the filaments extend, suggesting that the influx of osmoticum into the two sets of organs is independently controlled.     

A PERMINERALIZED FLOWER FROM THE MIDDLE EOCENE OF BRITISH COLUMBIA

A permineralized flower bud, two stamen clusters and one isolated stamen of similar morphology have been found in the black cherts of the Middle Eocene Allenby Formation of Princeton, British Columbia. Specimens were studied using a modified cellulose acetate peel technique and hydrofluoric acid. The single flower specimen, 4.5 mm long and 4.0 mm in diameter, represents half of a relatively mature bud of a bisexual flower with a superior ovary. The two-loculate pistil is 2.5 mm long with a solid style and a lobed stigmatic surface. No ovules have been observed in attachment. Twenty-two to 24 stamens are borne in three whorls or a tight helix. Pollen sacs of the anther are elongate with a thin connective while filaments are laminar. Anther walls contain rectangular cells with dark contents that also can be identified in isolated stamens or stamen clusters. Abundant stephanocolpate (pentacolpate), psilate pollen grains 20 μm in diameter have been isolated and examined using scanning and transmission electron microscopy. Grains are tectate, columellate with a broad foot layer that thins near the apertures, and an endexine of small platelets. The remains of four petals are surrounded by one large sepal, suggesting two in the whole flower. Morphological features of this flower are comparable to taxa of the Flacourtiaceae and Papaveraceae, but show closest similarities to the Eschscholziaeae of the Papaveraceae. Difficulties with reconciling the placement of this flower in the Eschscholziaeae and the known environment of deposition of the Princeton chert are discussed. The fossil material represents a new angiospermous taxon: Princetonia allenbyensis Stockey gen. et sp. nov., family Incertae sedis.     

Improvement of photosynthesis in zooxanthellate corals by autofluorescent chromatophores

Autofluorescent chromatophores were detected in 17 out of 71 zooxanthellate coral species studied. Chromatophores are localized either in the oral gastrodermic (endoderm) or oral epidermis (ectoderm). The pigment granules within the chromatophores (0.5–1.0 m in diameter) show a brilliant light-blue/turquoise autofluorescence (emission between 430 and 500 nm) after excitation with light of 365–410 nm. All species where the autofluorescent gastrodermal chromatophores form a compact layer, embedding the zooxanthellae, belong to the family Agariciidae. In contrast, some species of the Faviidae (2), Pectiniidae (1) and Mussidae (1) were found to have distinct, autofluorescent chromatophores in the oral epidermis. Autofluorescent pigments of the host may enhance photosynthesis of the symbionts as in Leptoseris fragilis. Short wavelength irradiance, less suitable for photosynthesis, is transformed by host pigments into longer wavelengths which are photosynthetically more effective. Thus, host species possessing autofluorescent chromatophores might have selective advantage over non-fluorescent species, and have the potential to survive in light-limited habitats. Furthermore, the daily period of photosynthesis is extended, thus increasing the energy supply and enhancing the deposition of skeletal carbonate. The absence or presence of chromatophores may have value in taxonomy and could putatively be of plalaeontological and palaeoecological interest.     

PERIANTH DEVELOPMENT OF POTAMOGETON RICHARDSONII

Interpretation of the Potamogeton flower is complicated by the attachment of the “perianth segment” to the stamen connective. Developmental studies show that the perianth segments are not outgrowths of the stamen connectives. They are initiated on the floral apex acropetally before the (superposed) primordia of the stamens. After the inception of the stamen primordia, growth occurs in the regions between the primordia of each perianth segment and stamen. Thereby the bases of the developing perianth segment and stamen become united, and in the adult flower eventually the perianth segment is inserted on the connective of the stamen. The primordium of the perianth segment develops from the 2 outer layers (tunica) of the floral apex, in contrast to the stamen primordium which originates from the 3 outer layers. The vascular bundles for each perianth segment–stamen region develop acropetally from 1 common bundle which bifurcates into 1 bundle for the perianth segment and 1 for the stamen. The bundle leading into the perianth segment branches in a more or less dichotomous manner. The veins form none or only 1 or 2 anastomoses at the base of the lamina, whereas the vein endings remain free. The interpretation of the perianth segments is discussed in terms of the classical and the gonophyll theory. Since both theories rest on an ambiguous methodological basis, interpretation is postponed until a new approach to comparative morphology has been worked out and until the floral development of other Helobiales has been studied.     

FLORAL DEVELOPMENT AND STAMEN FILAMENT ELONGATION IN CLEOME HASSLERIANA

Floral development in Cleome hassleriana is briefly described. Experimental evidence is presented supporting the hypothesis that the anthers control stamen filament elongation by supplying IAA rather than kinetin or gibberellic acid. This control depends upon the developmental stage of the bud and does not exclude the effect of other floral organs on stamen filament elongation at early developmental stages. Evidence that the anthers also partially control stamen filament and floral abscission by supplying IAA is given.     

OVERLAPPING ORGAN INITIATION AND COMMON PRIMORDIA IN FLOWERS OF PISUM SATIVUM (LEGUMINOSAE: PAPILIONOIDEAE)

The floral ontogeny of Pisum sativum shows a vertical order of succession of sepals, petals plus carpel, antesepalous stamens, and antepetalous stamens. Within each whorl, unidirectional order is followed among the organs, beginning on the abaxial side of the flower, as in most papilionoids. Unusual features include the four common primordia which precede initiation of discrete petal and antesepalous stamen primordia, and the marked overlap of organ initiations between whorls which are usually separately initiated. The stamens arise in free condition, then become diadelphous by intercalary growth at the base of nine stamens, and finally become pseudomonadelphous by surface fusion between the vexillary stamen filament and the adjacent edges of the filament tube. The early initiation of the carpel is not unique among papilionoids, but is somewhat unusual.     

ON THE ULTRASTRUCTURE OF CAMBIUM AND ITS VASCULAR DERIVATIVES. III. THE SECONDARY WALLS OF THE SIEVE ELEMENTS OF PINUS STROBUS

The sieve elements of Pinus strobus have thick, lamellate secondary walls, which are composed predominantly of cellulose and lesser amounts of polyuronides and pectins. Eight to 10 lamellae may be present in walls 2-3 μ in thickness. Each lamella represents a plane of high cellulose density which results from intersection of two parallel sets of fibrils. Polyuronides and pectins are more or less evenly distributed in the wall, possibly with a greater concentration near the middle lamella and the inner surface. Resemblance of these walls to the so-called nacré walls is indicated, and it is possible that the two represent the same structure.     

AN ANALYSIS OF STAMEN FILAMENT GROWTH OF NIGELLA HISPANICA

The post-meiotic stamen filament of Nigella hispanica L. under greenhouse conditions grows in length from 1 mm to approximately 10 mm at maturity in 16 days. Analysis of the filament epidermis suggests that the intercalary meristem is diffuse along the filament with a mid-point of activity near the center of the filament. The point of maximal activity, while initially central, is variable as cell division nears completion. Measurement of cell lengths along filaments suggests that an elongation gradient from base to tip is operative in filaments 1 mm and longer. Average cell lengths of epidermal cells increase faster than do those of terminal cells. Once average cell length begins to increase in any region of the epidermis it continues to do so until flower maturity. At maturity the longest epidermal cells are near the filament base and the shortest cells are at the tip. The differences between cell division and cell elongation patterns suggest that these two processes are controlled by different sites or substances. A comparison is made between the development of the Nigella filament and other determinate organs having intercalary meristems.     

MOVEMENT OF IAA IN SECTIONS FROM SPIDER FLOWER (CLEOME HASSLERIANA) STAMEN FILAMENTS

Movement of IAA in spider flower (Cleome hassleriana Chod.) stamen filaments was studied by placing 2-mm sections horizontally between donor agar blocks containing ¹⁴C-labeled IAA and plain agar receiver blocks and measuring radioactivity in the donor and receiver blocks and filament sections by scintillation counting after the desired transport time. Movement was strictly polar and basipetal at all stages of floral development, except in open flowers just before stamen abscission when the amounts moving acropetally and basipetally were equal. The amount of IAA moved depended upon the stage of development. As buds aged more IAA was moved, until the buds opened and the stamen filaments reached maximum elongation; then the amount of IAA moving basipetally dropped drastically. There was an insignificant amount of acropetal IAA movement except just before stamen abscission. This change in IAA movement is not due to a change in filament diameter. In time-course studies the amount of IAA moved basipetally increased with time up to 5 hr and then declined slightly. The amount of radioactivity retained by sections increased until 8 hr. The amount of IAA moved in tip sections was less than that in mid or base sections; however, this can be partially explained by differences in uptake area of these sections. The relationship of these results to the hypothesis that changes in IAA movement are important in the control of stamen filament elongation and abscission is discussed.     

Fluoreszenzmikroskopischer Nachweis des Schreckstoffes in den Schreckstoffzellen der Elritze,Phoxinus phoxinus (L.) (Cyprinidae,Ostariophysi, Pisces)

Zusammenfassung Die Schreckstoffzellen der Elritze,Phoxinus phoxinus (L.), zeigen nach Gefriertrocknung der Haut eine Eigenfluoreszenz. Diese wird bei 360–380 nm maximal angeregt; das Emissionsmaximum liegt bei ca. 515 nm. Die Fluoreszenz einer Schreckstoffzelle wird mit der Fluoreszenz des isolierten Schreckstoffes mikrospektralphotofluorimetrisch verglichen: die Emissions-maxima liegen nur 10 nm voneinander entfernt. Die Kurven relativer Fluoreszenzintensität verlaufen weitgehend gleichartig. Dies zeigt, daß der Schreckstoff tatsächlich den Schreckstoffzellen entstammt.

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Fluorescence microscopical demonstration of the alarm substance in the alarm substance cells of the European minnow,Phoxinus phoxinus (L.) (cyprinidae, ostariophysi, pisces)

Summary The alarm substance cells of the European minnow,Phoxinus phoxinus (L.), are autofluorescent after freeze-drying of the skin (Fig. 1). Their autofluorescence is maximally excited at 360–380 nm; the maximum of emission lies at about 515 nm. The fluorescence of an alarm substance cell is compared with the autofluorescence of the isolated alarm substance by means of a microspectro-photofluorometer. The maxima of emission are only about 10 nm apart. The curves of relative fluorescence intensity are almost identical (Fig. 3). These results show that the alarm substance actually comes from the alarm substance cells.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Description of Chytridiopsis Trichopterae N. Sp. (Microspora, Chytridiopsidae), A Microsporidian Parasite of the Caddis Fly Polycentropus Flavomaculatus (Trichoptera, Polycentropodidae), With Comments On Relationships Between the Families Chytridiopsidae and Metchnikovellidae

ABSTRACT. The microsporidium Chytridiopsis trichopterae n. sp., a parasite of the midgut epithelium of larvae of the caddis fly Polycentropus flavomaculatus found in southern Sweden, is described based on light microscopic and ultrastructural characteristics. All life cycle stages have isolated nuclei. Merogonial reproduction was not observed. the sporogony comprises two sequences: one with free spores in parasitophorous vacuoles, the other in spherical, 5.6-6.8 μm wide, sporophorous vesicles which lie in the cytoplasm. the free sporogony yields more than 20 spores per sporont. the vesicle-bound sporogony produces 8, 12 or 16 spores. the envelope of the sporophorous vesicle is about 82 nm thick and layered. the internal layer is the plasma membrane of the sporont; the surface layer is electron dense with regularly arranged translucent components. Both spore types are spherical. They have an ～ 35-nm thick spore wall, with a plasma membrane, an electron-lucent endospore, and an ～ 14-nm thick electron-dense exospore. the polar sac is cup-like and lacks a layered anchoring disc. the polar filament is arranged in two to three isofilar coils in the half of the spore opposite the nucleus. the coupling between the polar sac and the polar filament is characteristic. the surface of the polar filament is covered with regularly arranged membraneous chambers resembling a honeycomb. There is no polaroplast of traditional type. the cytoplasm lacks polyribosomes. the nucleus has a prominent, wide nucleolus. the two spore types have identical construction, but differ in dimensions and electron density. Free living spores are about 3.2 μm wide, the diameter of the polar filament proper is 102-187 nm, the chambers of the honeycomb are 70-85 nm high, and the polar sac is up to 425 nm wide. Living spores in the vesicle-bound sporogony are about 2.1 μm wide, the polar filament measures 69-102 nm, the chambers of the honeycomb are about 45 nm high, and these spores are more electron dense. Comparisons of cytology (especially the construction of the spore wall and the polar filament and associated structures) and life cycles reveal prominent differences among the Chytridiopsis-like microsporidia, and close relationships between the families Chytridiopsidae and Metchnikovellidae.     

CELL DIVISION AND THE ROLE OF THE PRIMARY WALL IN THE FILAMENTOUS DESMID ONYCHONEMA LAEVE (CHLOROPHYTA)1

Cell division and the role of the primary wall in filament formation in the desmid Onychonema laeve Nordst. were investigated by transmission and scanning electron microscopy. In addition, sequential chemical extractions and enzyme treatments were performed, on cell walls of intact filaments. Interphase cells are deeply constricted, consisting of two semicells, each elliptical in front view and circular in side view. In addition to two short lateral spines, each semicell has two apical processes that originate on opposite sides at an angle of about 15° from the central axis and overlap the adjacent cell. Division is initiated as in other desmids by a slight separation of the semicells and development of a girdle of primary wall material at the isthmus. In O. laeve the girdle of primary wall expands to form a spherical vesicle (termed a division vesicle) between the separating semicells. Nuclear division and septum formation occur in this vesicle when it is nearly the full diameter of the filament. Morphogenesis of the apical processes begins with completion of the septum, before the secondary wall appears. At maturity each apical process is surrounded by a thick layer of both secondary and primary wall, except that its capitate tip protrudes through the shroud of primary wall. Sequential treatment with hot ammonium oxalate, 4% NaOH, 17.5% NaOH and 10% chromic acid or various enzyme solutions did not cause filament breakage. SEM and TEM views of O. laeve after these treatments show intact secondary walls and intact primary wall material covering and connecting the apical processes of adjacent cells. It is the persistence of the primary wall between cells and around the apical processes that maintains the long, unbranched filamentous morphology of Onychonema laeve.     

Microspectrofluorometry of the autofluorescent flagellum in phototactic brown algal zoids

Summary Posterior flagella of zoids ofScytosiphon lomemaria andChorda filum (Phaeophyceae, Chromophyta) were isolated and subjected to microspectrofluorometry using a high sensitivity microspectrofluorometer in order to characterize the flagellar autofluorescent substances. Vigorous agitation in a Hypertonic medium yielded preparations of largely intact flagella retaining detectable green flagellar autofluorescence. Under 380–425 nm excitation light, maximum emission of flagellar autofluorescence was observed at 495 nm, whereas under 400–440 nm excitation light fluorescence shifted to around 510 nm. Comparison of these spectra with the fluorescence spectra of 4,5-cyclic FMN isolated from fertile thalli ofS. lomentaria, and of 6-carboxypterin suggested that two (or more) different fluorescent substances (presumably a flavin and a pterin) are present in the flagella.Abbreviations DTT dithiothreitol - FMN flavin mononucleotide - HEPES N-[2-hydroxyethyl]piperazine-N-[2-ethanesulfonic acid]) - PEG polyethylene glycol - PFB paraflagellar body - Tris tris(hydroxymethyl) aminomethane. Dedicated to Professors Masakazu Tatewaki and Tadao Yoshida on the occasion of their academic retirement     

商陆属2种植物花器官发生过程观察

该研究采用扫描电镜观察红蕊商陆(Phytolacca esculenta)和浙江商陆(Phytolacca zhejiangensis)的花器官发生过程,以明确商陆属植物花的基数,以及雄蕊和雌蕊是否具有叶性器官发生的特点,阐明商陆属植物花发生的模式。观察结果显示:(1)红蕊商陆和浙江商陆在花原基发生后,小苞片以2/5圆周相继发生,花被片的发生紧接小苞片的发生进行,花被与小苞片的发生均有顺时针和逆时针方向,且二者的发生方向始终一致。(2)花被发生结束后,雄蕊在花顶端分生组织的环状分生组织上发生,没有明显的发生顺序,近似同时发生;2轮雄蕊时内轮雄蕊先发生;外轮雄蕊有少数有时偶然与花被互生,但因外轮雄蕊数多于花被数,雄蕊与花被常不互生,也没有规律性。(3)红蕊商陆和浙江商陆的心皮都在雄蕊发生后,紧接着开始发生,且雌蕊与雄蕊(或内轮雄蕊)互生发生;心皮没有发生的先后次序,且每个心皮在基部连成一个整体形成雌蕊基部并发育成为子房。(4)红蕊商陆和浙江商陆的花基数为5,雄蕊和雌蕊的发生及数目不符合5基数的特点。研究认为,红蕊商陆和浙江商陆为5基数花,该研究结果不支持商陆属植物为3基数花的发生模式。