Behavior, Ecology, Evolution and Systematics Section, Campus Box 4120-Biological Sciences, Illinois State University, Normal, Illinois 61790-4120 USA.
Am J Bot. 2002 Feb;89(2):362-5. doi: 10.3732/ajb.89.2.362.
Attractive features of flowers are adaptations for biotic interactions, and a few floral adaptations are for interactions with the physical environment. Marginal corollar appendages of Nymphoides (Menyanthaceae) can be membranous, a fringe of trichomes, or a ruffle. Although clearly enhancing display, a fringed corollar margin might function by generating a significant upward force through surface tension, an interaction adaptive in an aquatic environment. The force needed to dunk flowers with an intact corollar fringe and those whose fringe had been trimmed showed a significant difference. The fringe added a mean of 10.4% to the floral mass, but the upward force generated increased by nearly 50%, a significant difference from the predicted change based upon buoyancy alone. A correlation between plant form and type of corolla margin supports the surface-tension hypothesis. The membranous and ruffled corollar margins were found in species whose flowers had less risk of contacting the water's surface.
花朵的吸引力特征是生物相互作用的适应，而一些花卉适应则是与物理环境的相互作用。水鳖属（Hydrocharitaceae）的边缘副花冠可能是膜状、毛边状或褶皱状。虽然明显增强了展示效果，但边缘副花冠的毛边可能通过表面张力产生显著的向上力来发挥作用，这种相互作用在水生环境中是适应性的。带有完整副花冠毛边的花朵和修剪过副花冠毛边的花朵的浸沉所需的力显示出显著差异。毛边使花朵的质量增加了平均 10.4%，但产生的向上力增加了近 50%，与仅基于浮力预测的变化有显著差异。植物形态和副花冠边缘类型之间的相关性支持了表面张力假说。在花朵接触水面风险较小的物种中发现了膜状和褶皱状的副花冠边缘。
