Modifications structurales des faisceaux vasculaires primaires de la tige deCordyline indivisa(Agavaceae). 2. Reacute;partition des diffeacute;rents stades structuraux dans le cylindre primaire, en fonction de la distance sous l'apex

摘要

InCordyline indivisaKunth, an anatomical modification occurs in the primary bundles, in relation to the pattern of their longitudinal course. Consequently, in a given transverse section of the stem, the bundles may be in different structural stages (collateral, intermediate types 1 and 2, amphivasal). All the procambial or primary vascular bundles in the upper 8.59ensp;mm of the stem of an 18-month-old plant were recorded. At regular intervals below the apex, the numbers and percentages of bundles showing each of the structural stages were also recorded. Based on the pattern of bundle construction previously shown for this species, the constitution of the primary cylinder at various distances below the apex is explained in relation to the distribution of the different structural stages.