Using scanning electron microscopy and thin sectioning, the functional morphology of the gynoecium, anthers, and pollen grains of Ruppia maritima, widgeon grass, were studied. The funnel-like arrangement of the carpels directing pollen to the stigmatic regions, the buoyancy offered by the presence o...

The organogenesis of floral development in the dioecious clonal tree species Rhus hirta offers an excellent model system to study gender expression in dioecious plants. Pistillate and staminate flowers from developing inflorescences were collected from Grover Island, located off the northern shore o...

In addition to two opposite cotyledons, germinating seedlings of V. riparia and Vitis cv. Vivant display two other phyllotactic patterns: (1) immediately following the emergence of the cotyledons, leaves are initiated individually in a spiral pattern, usually 2/5; (2) upon the initiation of the firs...

The Gulf of St. Lawrence Aster, Symphyotrichum laurentianum, is a member of the family Asteraceae and is listed as "threatened" by COSEWIC (Committee on the Status of Endangered Wildlife in Canada). This rare and vulnerable halophyte grows in only a few locations in New Brunswick, Prince E...

Background and Aims: By using the technique of replicas of a developing apex it is possible to obtain a direct measure of phyllotactic parameters (plastochrone and platochronic ratio) involved in the initiation of two successive primordia at the level of the SAM. The goal of this study is to compare...

The spadix of M. arborescens has a cylindrical or ellipsoid form at maturity and contains unisexual flowers without a perianth. The pistillate and staminate flowers are located in the basal and apical portions, respectively, of the inflorescence. In the upper portion of the female zone, there is a r...

In the intermediate zone of the inflorescence of genera of Aroideae one can find flowers with male and female characteristics. Until now, two types of developmental sequences of atypical bisexual flowers (ABFs) have been recognized: the Philodendron type and the Cercestis type. In the Philodendron t...

A comparative developmental study of the inflorescence of Philodendron solimoesense was conducted using scanning electron microscopy. The spadix of P. solimoesense is characterized by unisexual flowers. Staminate flowers are initiated on the upper portion of the spadix while pistillate flowers devel...

The spadix of Arum italicum Miller consists of two main parts: a clavate sterile portion (appendix) and a cylindroid fertile portion. In the fertile portion with both male and female zones, there are two zones of sterile flowers (bristles). The basal portion of bristles is surrounded by a verrucose ...

This study deals specifically with floral organogenesis and the development of the inflorescence of Philodendron squamiferum and P. pedatum. Pistillate flowers are initiated on the lower portion of the inflorescence and staminate flowers are initiated on the distal portion. An intermediate zone cons...

A modified mathematical model based on the concept of generative centres is proposed to describe organogenesis in young leaf primordia of Murraya paniculata. Measurements of specific parameters on leaf primordia at different stages of development support the basic assumptions of the model. These ass...

Previous studies on palm phyllotaxis deal mainly with the mature trunk. The goals of this study are (i) to determine the relationship between the number of parastichies, the divergence angle, and the plastochrone ratio at the level of the shoot apical meristem; (ii) to examine whether there are fluc...

The early stages of development of the inflorescence of Philodendron insigne were examined using scanning electron microscopy. Pistillate flowers are initiated on the lower portion of the inflorescence and staminate flowers are initiated on the distal portion. The male flowers have three to five sta...

The floral morphology of Ambrosina and Arisarum is analysed from a developmental and phylogenetic point of view. In Arisarum, there are atypical organs displaying male and female characteristics. This developmental study shows that the male flowers of Ambrosina are di- or tri-androus. A close phylog...

The early stages of inflorescence development in Philodendron fragrantissimum (Hook.) G. Don are examined using scanning electron microscopy. Pistillate flowers are initiated on the lower portion of the inflorescence and staminate flowers are initiated on the distal portion.

Leaf characters, such as angles between major veins, ratios of the length of leaf lobes, of leaf lobes and sinuses, and of petioles and leaf lobes, were measured on leaves of different sizes and compared against leaf blade length (an indirect measure of developmental time) to see if there were diffe...

S. laurentianum, the Gulf of St. Lawrence Aster, is an endemic aster of Prince Edward Island, New Brunswick, and the Magdalene Islands. It is considered by the Committee on the Status of Endangered Wildlife in Canada to be of special concern in Canada and to be critically imperiled in Prince Edward ...