Studies in the Alismataceae. X. Floral organogenesis in Luronium natans (L.) Raf.

2000 ◽  
Vol 77 (11) ◽  
pp. 1560-1568
Author(s):  
W A Charlton
Keyword(s):  
Floral Organ ◽  
Floral Organogenesis ◽  
Stamen Primordia ◽  
Floral Apex ◽  
Stamen Pairs

Floral organogenesis of Luronium natans (L.) Raf. occurs at first in an alternating trimerous pattern typical of Alismataceae, with the formation of three sepals, then three bulges, corresponding to the petal-stamen primordia described in some other Alismataceae, alternating with the sepals. A petal is initiated on each bulge and a pair of stamens is initiated either on it or close to it. After this, development no longer follows a trimerous plan. Six carpels are initiated in positions alternating with the six stamens, and further carpels may then arise above and between the first six. The carpels ultimately lie in a whorled arrangement if there are only six; if more, they may appear whorled or irregularly arranged. After the initiation of the stamen pairs, floral organ primordia appear simply to be positioned between pre-existing primordia as in other phyllotactic systems. It is suggested that the number of carpel primordia formed is probably determined by the size of primordia relative to the floral apex, and the extent of continued growth of the floral apex. Luronium reinforces the concept that a form of trimery is fundamental for the Alismataceae up to the formation of three stamen pairs and adds to the possibilities for variation after this point. It is suggested for the Alismataceae in general that, according to taxon, trimerous development may be terminated at any point after the initiation of the stamen pairs, and after this the primordia are positioned individually in relation to pre-existing primordia. The switch from stamen to carpel initiation is not necessarily correlated with these phyllotactic changes.

Floral organogenesis of Limnocharis flava

1977 ◽  
Vol 55 (9) ◽  
pp. 1076-1086 ◽  
Author(s):  
R. Sattler ◽  
V. Singh
Keyword(s):  
Floral Organogenesis ◽  
Stamen Primordia ◽  
Mature Flower ◽  
Stamen Pairs ◽  
Primary Pattern

Besides a trimerous calyx and corolla, the mature flower exhibits a polyandric androecium and an apocarpous gynoecium consisting of a whorl of carpels. Yet the primary pattern of the flower is completely trimerous and tetracyclic. After the inception of three sepals and three petals, three antesepalous primary androecial primordia are initiated each of which forms three stamens (i.e. secondary androecial primordia). Opposite these three groups of three stamen primordia, three groups of three carpels are initiated, possibly on three extremely inconspicuous primary gynoecial primordia. Additional carpel primordia are formed in varying numbers between the original three groups. Even before carpel inception, the three primary androecial primordia merge laterally thus forming an androecial ring. Additional stamen primordia arise on this ring first between the three groups of three stamen primordia and then in centrifugal direction as the androecial ring broadens basally. Eventually four whorls of stamens and two to three whorls of staminodia are formed secondarily on the androecial ring which arose from the primary primordia. Morphogenesis and construction of the flowers of Limnocharis flava differs in two major respects from those of all other taxa of the Alismatales studied thus far: (1) there are no stamen pairs primarily associated with the petals, and (2) the first-formed carpel primordia do not alternate with the stamen primordia of the preceding whorl, thus violating Hofmeister's rule of alternation.

Floral development of two species of Stylidium (Stylidiaceae) and some remarks on the systematic position of the family Stylidiaceae

1992 ◽  
Vol 70 (2) ◽  
pp. 258-271 ◽  
Author(s):  
Claudia Erbar
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Floral Biology ◽  
Systematic Position ◽  
Inferior Ovary ◽  
Stamen Primordia ◽  
Floral Apex ◽  
The Family ◽  
Transversal Plane

The early floral development of Stylidium adnatum and Stylidium graminifolium is characterized by an initial circular primordium whose areas in the transversal plane of the floral primordium show enhanced growth. The spiral inception of the five sepals starts before the differentiation of the initial circular primordium into two stamen primordia in transversal position (in relation to the floral diagram) and the corolla ring primordium below the stamen primordia. Then five petal primordia, which alternate with the sepals, arise on the corolla ring primordium (early sympetaly). Peculiar to the flowers of Stylidiaceae is the column that bears at its top both stigma and anthers. Probably this column should be interpreted as a receptacular tube. No distinct carpel primordia have been observed. The inferior ovary results from intercalary growth in the peripheral parts of the receptacle below the calyx, corolla, and stamen primordia. The residual floral apex gives rise to a transversal septum, by which the ovary becomes bilocular. None of the morphological, palynological, and embryological characters discussed contradicts a position of the Stylidiaceae near the Campanulales, and several of these characters support this position. Key words: Stylidiaceae, Campanulales, floral development, systematic position, floral biology.

Floral development in Melaleuca and Callistemon (Myrtaceae)

1998 ◽  
Vol 11 (6) ◽  
pp. 689 ◽  
Author(s):  
D. A. Orlovich ◽  
A. N. Drinnan ◽  
P. Y. Ladiges
Keyword(s):  
Floral Development ◽  
Flower Bud ◽  
Variable Expression ◽  
Total Absence ◽  
Stamen Primordia ◽  
Intermediate Morphology ◽  
Floral Apex

Floral development of seven species of Melaleuca and four species of Callistemon is compared. The multistaminate fascicles of Melaleuca develop from stamen primordia initiated on antepetalous pre-staminal bulges (PSBs); the resultant bundles of stamens become separated by hypanthial expansion as the flower bud enlarges. In most species of Callistemon examined the stamen primordia are initiated directly on the floral apex, and the stamens are distributed evenly around the hypanthium at anthesis. The possession of large and prominent PSBs, and thus stamen fascicles, is a feature of most species of Melaleuca and their total absence is a feature of most species of Callistemon; however, there is a continuum between these two extremes. Several taxa of both genera exhibit intermediate morphology. In C. glaucus (Bonpl.) Sweet, small but distinct PSBs develop, which influence antepetalous stamen groups that remain contiguous at anthesis. This also occurred in M. leucadendra (L.) L. This variable expression of PSBs is the result of differences in the timing of stamen initiation. Other variable features are determined by the space available for primordium initiation and the patterns of growth and expansion of the developing flower.

Net alignment of cellulose in the periclinal walls of the shoot apex surface cells in Kalanchoe blossfeldiana. II. Flower development

1990 ◽  
Vol 68 (12) ◽  
pp. 2678-2684 ◽  
Author(s):  
Amy J. Nelson
Keyword(s):  
Key Words ◽  
Shoot Apex ◽  
Flower Development ◽  
Cell Layer ◽  
Floral Organogenesis ◽  
Floral Apex ◽  
Kalanchoe Blossfeldiana ◽  
Periclinal Walls ◽  
Circumferential Reinforcement ◽  
Kalanchoë Blossfeldiana

Dome geometry and the pattern of net cellulose alignment in the periclinal walls of the surface cells of Kalanchoe blossfeldiana were examined during sequential stages of flower development. Floral apices of photoperiodically induced plants were dissected, stained, and observed under a dissecting microscope. The outermost cell layer(s) of the surface was surgically removed from the floral apex and viewed under a polarizing microscope. Correlations were found between the geometry of the dome, the pattern of cellulose in the surface cells, and the pattern of initiation of floral organs at the apex. Tangentially aligned cellulose was always observed around the periphery of the floral dome, whereas no net alignment of cellulose typically occurred in the centermost region. Circumferential reinforcement of cellulose was consistently observed at sites of incipient organ initiation, and the pattern of cellulose alignment on emerging primordia correlated with the type of organ development. No strict dependence was evident between the number and positioning of one whorl of floral ogans and that of the previous whorl. Key words: shoot, cellulose, flower, floral, organogenesis.

Studies in the Alismataceae. XII. Floral organogenesis in Damasonium alisma and Baldellia ranunculoides, and comparisons with Butomus umbellatus

2004 ◽  
Vol 82 (4) ◽  
pp. 528-539 ◽  
Author(s):  
W A Charlton
Keyword(s):  
Floral Development ◽  
De Novo ◽  
Fundamental Feature ◽  
Floral Organogenesis ◽  
General Plan ◽  
Stamen Pairs

Floral organogenesis of Damasonium alisma Mill. occurs at first in an alternating trimerous pattern typical of Alismataceae, with the formation of three sepals, then three bulges, corresponding to the CA (common perianth–androecium) primordia described in some other Alismataceae, alternating with the sepals. A petal is initiated on each bulge, and a pair of stamens is initiated either on or close to it. Three carpels are initiated in positions alternating with the petals and stamen pairs, and three further carpels then arise above and between the first three. At maturity and in fruit the carpels lie in a whorled arrangement. Floral development in Baldellia ranunculoides (L.) Parl. is identical up to the initiation of the six stamens. After this, six carpel primordia are formed alternating with the stamens, and further carpel primordia arise alternating with those previously formed. In Butomus, up to the initiation of the first six stamens, the general plan of development resembles that of the two Alismataceae. Three further whorls of organs arise in alternation: a whorl of three stamens arises over the stamen pairs followed by two whorls each of three carpel primordia. It is argued that the trimerous appearance of the whorl of sepals (or outer perianth in Butomus) arises de novo and represents a genuine expression of trimery. However, most of the subsequent features of development in these flowers can be seen as arising from phyllotactic mechanisms that cause new primordia to arise between and above pre-existing ones. Consequently the appearance of trimerous or hexamerous whorls above the first whorl of perianth does not represent a fundamental feature of development. The nature of variations in the positional relationships of inner perianth, stamen, and carpel primordia in various Alismataceae and Butomus strengthen the case that there is a significant developmental association between inner perianth members and associated pairs of stamens, which may be connected with the evolution of the flowers from pseudanthial structures.Key words: Baldellia, Butomus, Damasonium, Alismatidae, flower, organogenesis.

Floral development and systematic position of Eucalyptus curtisii (Myrtaceae)

1991 ◽  
Vol 4 (3) ◽  
pp. 539 ◽  
Author(s):  
AN Drinnan ◽  
PY Ladiges
Keyword(s):  
Phylogenetic Tree ◽  
Floral Development ◽  
Systematic Position ◽  
Stamen Primordia ◽  
Floral Apex

The corolla of E. curtisii Blakely & White clearly consists of free, imbricate parts that closely adhere by their cuticles. Ontogenetic investigation of the corolline parts did not reveal any suggestion of morphological duality that characteristically leads to the complex 'petals' in Angophora and other eucalypts. The stamen primordia are initiated on the inner flank of the invaginated floral apex, and at anthesis are inserted on the rim of the hypanthium. There is no evidence of a stemonophore distinctive of the informal subgenera Eudesmia, Symphyomyrtus and Monocalyptus. The possession of the plesiomorphic condition for both these characters is suggestive of a 'primitive' position for E. curtisii close to the root of the eucalypt phylogenetic tree. This is supported by the possession of several other characters that are apparently plesiomorphic for Eucalyptus sens. lat.

scholarly journals Comparison of synandrium structure and development in three species from the Myristicaceae

Botany ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Gui-Fang Yang ◽  
Feng-Xia Xu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vascular Bundle ◽  
Developmental Stages ◽  
Floral Meristem ◽  
Stamen Primordia ◽  
Floral Apex ◽  
Morphology And Structure ◽  
Myristica Fragrans Houtt ◽  
Scanning Electron

Species of Myristicaceae have diverse morphology and structure of their synandria, making them an interesting group for androecium evolution research. To clarify the morphology, structure, and origin of the synandrium, scanning electron microscopy and histology were performed on staminate flowers of Horsfieldia pandurifolia H.H.Hu, H. tetratepala C.Y.Wu & W.T.Wang, and Myristica fragrans Houtt. at different developmental stages. A whorl of stamen primordia was rapidly initiated around the margin of the floral apex in groups of two in H. pandurifolia and groups of three in M. fragrans. Each stamen primordium grew longitudinally, producing a pair of anther lobes and four microsporangia, accompanying one vascular bundle in H. pandurifolia and M. fragrans. In H. tetratepala, three stamen primordia groups were formed, and each group with several anthers was supported by one vascular bundle, indicating a secondary increase of stamen. Three types of synandrium origin were observed: in M. fragrans, the central sterile column tissues originated from the elongate receptacle; in H. pandurifolia and H. tetratepala they were derived from a combination of floral meristem and fused connectives, and a combination of receptacular tissue and stamen groups. The diverse origins of the central sterile column suggest that the synandrium develops differently and independently in different genera and species of Myristicaceae.

scholarly journals Comparative Ontogeny of Hermaphrodite and Pistillate Florets in Helianthus annuus L. (Asteraceae)

2012 ◽  
Vol 4 (2) ◽  
pp. 30-40 ◽  
Author(s):  
Aslıhan ÇETİNBAŞ ◽  
Meral ÜNAL
Keyword(s):  
Helianthus Annuus ◽  
Apical Meristem ◽  
Floral Organ ◽  
Floral Meristem ◽  
Inferior Ovary ◽  
Helianthus Annuus L ◽  
Stamen Primordia ◽  
Flower Organs ◽  
Short Time ◽  
Further Development

The inflorescence of Helianthus annuus L. has two types of flowers (or florets) on a single capitulum; central hermaphrodite disc florets and peripheral pistillate ray florets. In both florets, reproductive development starts with the conversion of apical meristem into floral meristem that will produce floral organ primordia. The only difference between hermaphrodite and pistillate florets in apical meristem stage is that apical meristem of the pistillate florets is not as apparent and curvaceous as apical meristem of the hermaphrodite florets. The differentiation of apical meristem into floral meristem is in the same progress in both florets. In hermaphrodite florets, flower organs; petals, stamens and carpels develop from floral meristem. Differentiation of five petal primordia takes place in the same way in both florets. Firstly filament and then anther differentiates in a stamen. Two carpel primordia appear below the stamen primordia in hermaphrodite florets. In following stages, carpel primordia are lengthened and formed inferior ovary, style, stigma respectively. In pistillate florets, flower organs; petals and carpels develop from floral meristem. They pass directly from the periant initiation to the start of carpel formation. Stamen primordia don’t appear and the further development of carpel primordia stops in a short time, as a result, stigma and style do not exist in pistillate florets. However, an inferior ovary with no ovule forms. In the capitulum of hermaphrodite florets, the development takes place in a centripetal manner; it starts firstly on the outermost whorl, and it proceeds towards inner whorl. However, this is not the case in pistillate florets.

scholarly journals Stability Despite Reduction: Flower Structure, Patterns of Receptacle Elongation and Organ Fusion in Eriocaulon (Eriocaulaceae: Poales)

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1424
Author(s):  
Dmitry D. Sokoloff ◽  
Shrirang R. Yadav ◽  
Arun N. Chandore ◽  
Margarita V. Remizowa
Keyword(s):  
Flower Development ◽  
Floral Organ ◽  
Complete Loss ◽  
Flower Structure ◽  
Male And Female ◽  
Stamen Primordia ◽  
Early Flower ◽  
Structure Patterns ◽  
Sem Investigation ◽  
Female Flowers

Eriocaulaceae (Poales) differ from potentially related Xyridaceae in pattern of floral organ arrangement relative to subtending bract (with median sepal adaxial). Some Eriocaulaceae possess reduced and non-trimerous perianth, but developmental data are insufficient. We conducted a SEM investigation of flower development in three species of Eriocaulon to understand whether organ number and arrangement are stable in E. redactum, a species with a highly reduced calyx and reportedly missing corolla of female flowers. Early flower development is similar in all three species. Male and female flowers are indistinguishable at early stages. Despite earlier reports, both floral types uniformly possess three congenitally united sepals and three petals in E. redactum. Petals and inner stamens develop from common primordia. We assume that scanning electron microscopy should be used in taxonomic accounts of Eriocaulon to assess organ number and arrangement. Two types of corolla reduction are found in Eriocaulaceae: suppression and complete loss of petals. Common petal–stamen primordia in Eriocaulon do not co-occur with delayed receptacle expansion as in other monocots but are associated with retarded petal growth. The ‘reverse’ flower orientation of Eriocaulon is probably due to strictly transversal lateral sepals. Gynoecium development indicates similarities of Eriocaulaceae with restiids and graminids rather than with Xyridaceae.

Floral development of Butomus umbellatus

1974 ◽  
Vol 52 (1) ◽  
pp. 223-230 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Tunica Layer ◽  
Rapid Sequence ◽  
Floral Apex ◽  
Outer Tepal ◽  
Primary Pattern

The primordia of the floral appendages appear in acropetal succession and develop in the order in which they appear. The primordia of each whorl of appendages are formed in a rapid sequence. After the inception of outer tepal primordia, the floral apex becomes triangular. On each angle, one inner tepal primordium together with the primordia of a pair of outer stamens and an inner stamen is formed. The triangularity of the floral apex might be interpreted as an indication of the formation of petal–stamen (CA) primordia as reported for Alisma and Hydrocleis. If this is the case, the primary pattern of organogenesis of the Butomus flower is trimerous and tetracyclic, i.e. one whorl of outer tepals, one complex of inner tepals and stamens, and two whorls of pistils. The floral apices have a two-layered tunica surrounding a central corpus. The initiating divisions in the formation of all floral appendages occur in the second tunica layer. In the case of stamen primordia, the outer corpus is also involved. Procambial development is acropetal. One procambial strand differentiates into each floral appendage shortly after its inception. Additional procambial strands are formed in the pedicel and the perianth and gynoecium. The relationships of Butomus to the Magnoliidae are discussed.

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