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Although Rhododendron spp. anthers have apical pores and should be expected to be buzz pollinated, bees do not normally sonicate them to release pollen. Stamens were examined to determine their pollen release mechanism; the filaments were shown to have natural vibration modes that cause pollen to be forcibly ejected by vibration, providing the pollen is mature. The first natural vibration mode of the stamens was found to generate centrifugal force sufficient to throw the pollen toward the apical pore and out of the anther, so that it adheres to the anther tip and hangs in the bee's path to the nectaries. These vibrations may be triggered by bees brushing past the long stamens when foraging for nectar, so that the flowers retain their pollen until insect vectors begin foraging on them. The low frequency vibration modes of the viscin threads, which hold the pollen together, may contribute towards the pollen ejection by low frequency stamen vibration. Vibration transmission of dehiscent anthers containing pollen was good from 50 Hz to 850 Hz, suggesting that sonication should be an efficient method of pollen collection, although this rarely occurs. Vibratory ejection occurs at a constant energy level, rather than the constant force levels found in previous research on Actinidia.

Leaves of most monocotyledonous plants gain structural stiffness from curling or folding. This is shown to be true of Phormium spp., where the optimisation seems to be for the leaf to gain as much stiffness as possible by curling longitudinally whilst keeping the maximum amount of projected area available for intercepting light. Smaller plants with less leaf fibre have to fold about the midrib to gain this stiffness, which will reduce their projected area more than curling would but reduces the investment in fibre content.

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