Bamboo (Phyllostachys spp.) culms exhibit hollow and tapered geometries with remarkable mechanical robustness, yet the mechanical significance of these morphologies remains poorly understood. This study aimed to understand the biophysical parameters of bamboo stems and explore why they are tapered and hollow, while taking different loading conditions into consideration. Representing stems as hollow, tapered beams, tapering ratios were assessed for their ability to minimise maximum bending stress. An ‘optimal tapering law’ was derived for an axially graded, hollow, tapered cantilever beam under uniformly distributed load and compared to a beam under point load. Theoretical analysis was conducted to investigate how loading and hollowing of a beam made from axially functionally graded material affect the optimal tapering ratio. This law helps explain bamboo’s hollow, tapered structure, demonstrating that stems follow optimal tapering laws suited to their growth environments. These can be translated into general design rules for lightweight, wind-resistant structures.

The formation of xylem and phloem by the vascular cambium is a cellular process that is influenced by biotic and abiotic factors at sub-seasonal timescales. However, the significance of cambial activity extends across space (up to ecosystems) and time (up to centuries). This relates to the functional importance of xylem and phloem and the extremely long persistence of woody tissues, which are also a major carbon sink. Hence, studying this phenomenon involves a wide variety of approaches and methods that fundamentally vary in their temporal and spatial scales. From global vegetation dynamics to maple syrup production, the articles in the special collection ‘Advances in Xylem and Phloem Formation Research’ well reflect this diversity. Collectively, they reveal the complexity of underlying mechanisms and the potential for implementation of simpler schemes into global models.

Phyllotaxis, the regular arrangement of lateral organs initiated at the shoot apical meristem (SAM), has long served as a model for studying pattern formation in plants. Gymnosperms, due to their crystal-like organ arrangements, suitable for geometric analyses, were often used in phyllotactic research. In addition, the interrelationship between phyllotaxis and the primary vascular system became well-recognised. Here, we review classical morphological and anatomical data together with recent molecular findings to reevaluate gymnosperms as a model system for phyllotaxis regulation. We discuss the diversity and ontogenetic dynamics of phyllotactic patterns, their close relation with SAM structure and activity and the role of the vascular system as a potential constraint stabilising pattern propagation and chirality. Available evidence suggests that auxin-dependent mechanisms are evolutionarily conserved, but operate within diverse structural contexts. We propose that integrating classical datasets with modern experimental and modelling approaches, applied to gymnosperms, can reveal fundamental principles governing phyllotaxis regulation.