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.

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 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.

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.

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 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 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.

Molecular data allow to elucidate the taxonomic placement of some Umbelliferae from Middle Asia and Afghanistan (Pinacantha, Ladyginia, Peucedanum mogoltavicum)

Phytotaxa ◽  
2018 ◽  
Vol 350 (1) ◽  
pp. 42 ◽  
Author(s):  
GALINA V. DEGTJAREVA ◽  
MICHAEL G. PIMENOV ◽  
TAHIR H. SAMIGULLIN
Keyword(s):  
Phylogenetic Tree ◽  
Dna Sequence ◽  
Sequence Data ◽  
Molecular Data ◽  
Systematic Position ◽  
New Combination ◽  
Dna Sequence Data ◽  
Middle Asia ◽  
Molecular Phylogenetic Tree ◽  
Molecular Phylogenetic

The systematic position of three Apiaceae-Apioideae taxa, Pinacantha porandica, Ladyginia bucharica and Peucedanum mogoltavicum, from Middle Asia and Afghanistan, is clarified based on nrITS DNA sequence data. In the molecular phylogenetic tree, the monotypic Pinacantha is placed in unresolved position within the Ferulinae. Although there is no morphological information on essential characters, we propose a new position of Pinacantha porandica within the genus Ferula. As a result a new combination Ferula porandica is proposed, with a new section Pinacantha to accommodate it. The attribution of Peucedanum mogoltavicum to Ferula has been confirmed, its correct name being Ferula lithophila. The genus Ladyginia should not be included in Ferula, its closest relatives being Mozaffariania and Glaucosciadium from the Glaucosciadium Clade.

Aspects of inflorescence and floral development in the putative basal angiosperm Amborella trichopoda (Amborellaceae)

2003 ◽  
Vol 81 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Usher Posluszny ◽  
P Barry Tomlinson
Keyword(s):  
Floral Development ◽  
Close Packing ◽  
Basal Angiosperm ◽  
Size Difference ◽  
Tunica Layer ◽  
Flat Base ◽  
Floral Apex ◽  
Rapid Transition ◽  
Basal Meristem ◽  
Female Flowers

Amborella has woody axes whose development is intrinsically plagiotropic and determinate. The tree habit is achieved through overtopping of older axes by basally produced younger axes, as in Mangenot's model. Inflorescence units, which are produced in the axils of distal leaves, may be described as extended cymes, each branch ending in a flower. Basal bracteoles have a decussate arrangement, which is modified to an alternate phyllotaxis distally. Flowers produce one or more additional bracteoles with a rapid transition to the spiral phyllotaxis of the broad overlapping tepals. In this transition the initially conical floral apex becomes invaginated to form a floral cup, with subsequent appendages appearing on its inner margin. The floral apex then forms the flat base of the cup but retains a discrete single tunica layer. The receptacular bowl is deepened and narrowed by the basal meristem of each appendage, the last formed floral organs usually consuming the floral meristem. Sexual parts are more numerous in male than female flowers, accounting for their size difference, but primordia of stamens and carpels are initially very similar. Floral symmetry is largely a consequence of close packing of appendages within the floral cup. In its initial stages of development the flower does not conform to any conventional floral model in angiosperms and is better regarded as highly specialized rather than ancestral in its synorganization. This is not unexpected in a lineage of such long independent evolution.Key words: Amborella, basal angiosperm, development, inflorescence, primitive flower.

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’

1986 ◽  
Vol 64 (8) ◽  
pp. 1620-1631 ◽  
Author(s):  
Usher Posluszny ◽  
Jean M. Gerrath
Keyword(s):  
Fourth Order ◽  
Floral Development ◽  
Upper Arm ◽  
Grape Cultivar ◽  
Stamen Primordia ◽  
Short Style

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’ was studied. A tendril forms opposite the last-formed leaf on the shoot but is slightly delayed in its initiation. Six nodes and 10 primordia complete one leaf–tendril initiation cycle. The inflorescence develops at the same site and is initially indistinguishable from the tendril. Inflorescence primordia are initiated on the upper arm, first opposite each other in a decussate arrangement and then apparently spirally. Each inflorescence primordium may subsequently initiate two lateral primordia, which become subtended by bracts. These in turn may repeat the pattern so that ultimately third- or fourth-order cysmose inflorescence branches may be produced. During floral development the calyx is initiated at first as three primordia, followed by a ring, which ultimately develops five lobes. The five corolla primordia alternate with the sepals. The five stamen primordia are initiated opposite the petals. The gynoecium initiates as five primordia, which later become a ring. Two septae are initiated opposite each other on the inner flank of the ring, forming the two-loculed ovary. Each septum forms a placenta, giving rise to two ovules. The upper portion of the gynoecial ring grows up over the ovules and forms the short style and discoid stigma.

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