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A histo-morphological investigation of indirect somatic embryogenesis was conducted on three species of Iris. The formation of "calli I" or propagules appears somewhat like a root ramification. It is initiated in the pericycle, facing one of the xylem bundles. Fully developed, this so-called callus I differs from a rootlet by its size as well as by the complete absence of an apical meristem and the quasi absence of a root cap. In terms of external and internal structures, it is different from the typical callus of other plants as well as the callus II of Iris. The latter becomes granular on the surface and is internally parenchymatous. This type of callus has an irregular growth that suggests unequal activity of a lateral meristem. This meristem is covered by a discontinuous plectenchyma or pseudoparenchyma of variable thickness that is cytologically heterogeneous. Most of the initial cells of somatic proembryos and embryoids develop in this pseudoparenchyma, of which some fragments remain attached to the embryoids until their development is complete. Key words : Iris, roots, micropropagation, indirect somatic embryogenesis, histology.

In this paper, the authors describe the main features of more than 100 teratological samples spontaneously produced, during the past 5 years, by the hybrid No. 6488-37 of the Montreal Botanical Garden's collection of honeysuckles. The unusual appearance of all these specimens is due to the union, by gamophylly, of flowering twigs, which are most often inserted in foliar axils vertically separated by a well-developed internode.The constant position of the united flowering twigs' insertion point on the main axis of all these samples, the normal or subnormal morphological and anatomical structure of those twigs, and the very small junction area (maximum length 500 μm) of their fused leaves, as also the relative initial position, and (or) the time interval between the respective periods of initiation of the united organs, indicate (1) that these gamophyllies undoubtedly have an ontogenetic or postgenital origin and (2) that the adhesion of the fused foliar areas must have occurred during the intensive intercalary growth of the flowering branches.The histocytological study of areas of gamophylly of the samples shows also that the intimate fusion of the leaves' parts, accidentally brought together, is generally accompanied by a local cellular dedifferentiation and an intensive cell proliferation. The first of these phenomena would correspond in a way to a contact allergy, whereas the second would result from injuries.

This paper is mainly concerned with the anatomical and morphological features of over 15 teratological samples of honeysuckle showing diverse types of "concaulescence."Most frequently, "concaulescence" is the only abnormality present and three different morphological–anatomical types of adnation may be distinguished. (1) The adnated sprigs (hypopodia) are attached to the main axis by a narrow strip of cortex; both the sprig gap and the seriated buds are located at their usual level. (2) The vascular bundles of the adnated axes separate themselves progressively, and frequently there is no seriated bud at the axil of the adnated sprigs. (3) The lateral sprigs remain closely fused with the main axis until they free themselves abruptly and then the seriated buds appear at the free axil.Studies of the other samples are complicated by the occurrence of some phyllotaxic anomalies below the adnation area. Among these anomalies the most frequent are (1) the vertical displacement between the opposite petiole insertion area of the node and (2) the stretching of the foliar bases and the accompanying sessile leaves at this abnormal node.