The conventional concept of an 'undifferentiated perianth', implying that all perianth organs of a flower are alike, obscures the fact that individual perianth organs are sometimes differentiated into sepaloid and petaloid regions, as in the early-divergent angiosperms Nuphar, Nymphaea, and Schisandra. In the waterlilies Nuphar and Nymphaea, sepaloid regions closely coincide with regions of the...

For most angiosperms, producing and maintaining flowers is critical to sexual reproduction, yet little is known about the physiological processes involved in maintaining flowers throughout anthesis. Among extant species, flowers of the genus Calycanthus have the highest hydraulic conductance and vein densities of species measured to date, yet they can wilt by late morning under hot conditions. ...

Senescence is a tightly regulated process and both compartmentalisation and regulated activation of degradative enzymes is critical to avoiding premature cellular destruction. Proteolysis is a key process in senescent tissues, linked to disassembly of cellular contents and nutrient remobilisation. Cysteine proteases are responsible for most proteolytic activity in senescent petals, encoded by a...

Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular traditional potted flower well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, ‘Jinzhan Yintai’ ‘Yulinglong’. Recently, mutant yellow tepals observed promptly became popular. To clarify the key pi...

on the circular curve, lateral acceleration affects comfort. on the spiral, both lateral acceleration and jerk affect comfort.  the determination of maximum curving speed on the basis of lateral acceleration only is not critical because the lateral acceleration is proportional to the square of speed whereas jerk is proportional to cubic power of speed. the maximum speed on a curve is thus signi...