Floral development of Hydrocleis nymphoides

1973 ◽  
Vol 51 (12) ◽  
pp. 2455-2458 ◽  
Author(s):  
R. Sattler ◽  
V. Singh
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Stamen Primordia ◽  
Floral Apex

After the inception of three sepal primordia, three petal-stamen (CA) primordia (bulges) are formed in alternisepalous positions. On each of these bulges a petal is initiated, followed by a pair of stamens relatively high up on the bulge, where it is continuous with the floral apex. Growth extends between the three bulges, thus forming an inconspicuous circular rim around the floral apex. As this rim increases in size, further stamens and eventually staminodia are formed centrifugally on the rim. Five or six carpel primordia are initiated centrally to the first-formed pairs of stamen primordia long before all stamens and staminodia have appeared. In spite of considerable deviations from the trimerous monocotyledonous floral construction, the primary organogenetic pattern is trimerous (with the exception of at least the pentamerous flowers) and it is comparable to the primary patterns found in Alisma, Butomus, and other Alismatales. Thus, the study of the earliest developmental stages reveals a common plan that is elusive in later developmental stages and mature flowers.

Floral development in the 'Symphyomyrtus group' of Eucalypts (Eucalyptus: Myrtaceae)

1991 ◽  
Vol 4 (3) ◽  
pp. 553 ◽  
Author(s):  
AN Drinnan ◽  
PY Ladiges
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Growth Centre ◽  
Superficial Resemblance ◽  
Stamen Primordia ◽  
Mature Flower ◽  
Floral Apex ◽  
Bud Growth ◽  
Early Developmental ◽  
Complete Interpretation

Floral development is described in selected species of informal subgenus Symphyomyrtus (Pryor and Johnson 1971). The corolline operculum in most species is equivalent to those of informal subgenera Eudesmia, Idiogenes (E. cloëziana) and Monocalyptus. It is formed by growth centre continuity, and shows characters consistent with the dorsal components of Angophora and bloodwood corolline parts. Stamen primordia form on a corolline buttress that develops into the stemonophore of the mature flower. This feature is a synapomorphy for Symphyomyrtus sens. strict., Eudesmia, Idiogenes and Monocalyptus. Eucalyptus microcoiys has the plesiomorphic conditions of four free imbricate petals that show no evidence of compound development, and stamens arising directly on the floral apex, not on a stemonophore precursor. The apparent bundling of stamens is a result of differential bud growth, and bears only a superficial resemblance to stamen groups in Eudesmia eucalypts. The corollas of E. brachyandra (informal subgenus Telocalyptus) and E. guilfoylei (Symphyomyrtus) also consist of free, simple petals, but the unavailability of early developmental stages precludes a complete interpretation of these and the remaining three species of Telocalyptus.

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.

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.

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.

Morphological and anatomical development in the Vitaceae. IV. Floral development in Parthenocissus inserta

1989 ◽  
Vol 67 (5) ◽  
pp. 1356-1365 ◽  
Author(s):  
Jean M. Gerrath ◽  
Usher Posluszny
Keyword(s):  
Floral Development ◽  
Three Dimensional ◽  
Floral Ontogeny ◽  
Inflorescence Branch ◽  
Stamen Primordia ◽  
Floral Apex

The floral ontogeny of Parthenocissus inserta, based on histological and three-dimensional observations, is presented. The inflorescence primordium arises in a leaf-opposed position at two of three nodes. It becomes subtended by a bract, and then bifurcates equally to form a lateral and a main arm. Inflorescence branches are initiated on both arms to form a series of dichasia. The transition from inflorescence branch primordium to floral primordium is marked by the initiation of three sepal primordia. Subsequently a ring primordium forms as the fourth and fifth sepal primordia are initiated, resulting in a calyx which encircles the floral apex. Petals and stamens arise simultaneously as five common petal–stamen primordia, alternating with the sepals. They bifurcate to form separate petal and stamen primordia. The petals are greenish, valvate, hooded, and are separate at maturity. The tetrasporangiate anthers are introrse and pollen is tricolporate. The gynoecium arises as a ring primordium. Two septa arise from the inner gynoecial wall and the floral apex, and will eventually form an essentially two-loculed superior ovary. Two ovules are initiated from the base of each septum. Each of the four ovules is anatropous and bitegmic at maturity. A disc arises from the base of the gynoecium. It appears as five pinkish protuberances of the ovary base at maturity and secretes a nectarlike substance. The fruit is a one- to four-seeded blue-black berry.

Floral development of Potamogeton densus

1973 ◽  
Vol 51 (3) ◽  
pp. 647-656 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
The Other ◽  
Floral Meristem ◽  
Developmental Sequence ◽  
Initial Activity ◽  
The Third ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Inflorescence Axis ◽  
Rates Of Growth

The floral appendages of Potamogeton densus are initiated in an acropetal sequence. The first primordia to be seen externally are those of the lateral tepals, though sectioning young floral buds (longitudinally, parallel to the inflorescence axis) reveals initial activity in the region of the lower median (abaxial) tepal and stamen at a time when the floral meristem is not yet clearly demarcated. The lateral (transversal) stamens are initiated simultaneously and unlike the median stamens each arises as two separate primordia. The upper median (adaxial) tepal and stamen develop late in relation to the other floral appendages, and in some specimens are completely absent. Rates of growth of the primordia vary greatly. Though the lower median tepal and stamen are initiated first, they grow slowly up to gynoecial inception, while the upper median tepal appears late in the developmental sequence but grows rapidly, soon overtaking the other tepal primordia. The four gynoecial primordia arise almost simultaneously, although variation in their sequence of inception occurs. The two-layered tunica of the floral apices gives rise to all floral appendages through periclinal divisions in the second layer. The third layer (corpus) is involved as well in the initiation of the stamen primordia. Procambial strands develop acropetally, lagging behind primordial initiation. The lateral stamens though initiating as two primordia each form a single, central procambial strand, which differentiates after growth between the two primordia of the thecae has occurred. A great amount of deviation from the normal tetramerous flower is found, including completely trimerous flowers, trimerous gynoecia with tetramerous perianth and androecium, and organs differentiating partially as tepals and partially as stamens.

Comparative floral development reveals novel aspects of structure and diversity of flowers in Cannabaceae

2020 ◽  
Vol 193 (1) ◽  
pp. 64-83 ◽  
Author(s):  
Flávia M Leme ◽  
Jürg Schönenberger ◽  
Yannick M Staedler ◽  
Simone P Teixeira
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Cannabis Sativa ◽  
Glandular Trichomes ◽  
Flower Morphology ◽  
Ovule Development ◽  
3D Reconstructions ◽  
Development Stages ◽  
Broad Base ◽  
Trema Micrantha

Abstract Species of Cannabaceae are wind pollinated, have inconspicuous and reduced flowers that are pistillate, staminate and apparently perfect on the same individual or on different individuals, with a single-whorled perianth and a pseudomonomerous gynoecium. Our objective is to understand the developmental processes that lead to such a reduced flower morphology and polygamy in Cannabis sativa, Celtis iguanaea and Trema micrantha. Floral buds and flowers were processed for surface, histological examinations and 3D reconstructions of vasculature. The single-whorled perianth is interpreted as a calyx because the organs are robust, have a broad base, an acute apex and quincuncial aestivation and are opposite the stamens. Petals are absent from inception. The dicliny is established at different development stages: stamens or carpels are absent from inception (Cannabis sativa), initiated and aborted during early (Trema micrantha, before sporo/gametogenesis) or late (Celtis iguanaea, after sporo/gametogenesis) development. Furthermore, in all species studied the carpels are congenitally united and the pseudomonomerous nature of the gynoecium is confirmed. Glandular trichomes are distributed on the bracts, sepals, anther connective and receptacle. Special floral features shared by species of Cannabaceae include precocious ovule development and sepals that are each vascularized by one bundle. The reduced flowers of Cannabaceae are the result of the absence from inception and/or abortion of organs and even of a whole whorl at different developmental stages, which were probably selected in response to pressures exerted by the similar pollination mechanism.

Development in vitro of surgically halved stamen primordia of tobacco

1972 ◽  
Vol 50 (11) ◽  
pp. 2396-2400 ◽  
Author(s):  
G. S. Hicks
Keyword(s):  
Developmental Stages ◽  
Floral Meristem ◽  
Stamen Primordia ◽  
Development In Vitro

Tobacco stamen primordia at different developmental stages were surgically bisected and cultured while still attached to the floral meristem. The youngest incised primordia frequently regenerated two stamen primordia each with the characteristic four anther lobes. No regeneration was observed from the oldest stamen rudiments bisected and these formed only half-stamens. It is suggested that normally a stamen rudiment passes through a labile phase and that the pattern of the organ is subsequently fixed in the primordium.

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