Taxonomic and Adaptive Significance of Hollow Plant Organs

许多物种的植物，在完全不同的谱系， 其特征在于定期生产空心茎， 有隔膜的节;竹子是典型的例子，马尾也是 (the属Equisetum）。 在草或竹的种类中 科，空心茎占主导地位的固体茎;种之间 所有现存的物种都能产生 空心茎 为了检测生物力学特性 康奈尔大学的卡尔·尼克拉斯博士将使用 一种被称为多重共振频率的工程技术 光谱（MRFS）分析在几个物种的研究 马尾和草。 机械刚度或弯曲刚度 茎的刚性被认为与光截获有关 和繁殖（孢子或种子生于茎上）。 争论的焦点是假设的效率之间的权衡， 结构（中空杆假定为“更便宜” 代谢）和断裂安全性（假定实心股骨柄 提供更大的力量）。 股骨柄的力学性能 将进行分析，并对刚性方面进行量化， 测量，在一系列的物种从草和马尾 家庭 空心杆结构的共同特点， 两个亲缘关系遥远的植物群很可能提供 趋同进化的例子。

Plants of many species, in quite different lineages, are characterized by the regular production of hollow stems with septate nodes; bamboos are classical examples, as are horsetails (the genus Equisetum). Among species of the grass or bamboo family, hollow stems predominate over solid stems; among species of the ancient horsetail family, all extant species produce hollow stems. In order to examine the biomechanical properties of hollow stems, Dr. Karl Niklas of Cornell University will use an engineering technique known as multiple resonance frequency spectra (MRFS) analysis in the study of several species of horsetails and of grasses. The mechanical rigidity, or flexural rigidity, of stems is thought to be related to light-interception and to reproduction (either spores or seeds borne on that stem). At issue is the hypothesized trade-off between efficiency in construction (hollow stems presumed to be "cheaper" metabolically) and safety from breakage (solid stems presumed to provide greater strength). The mechanical properties of stems will be analyzed, and aspects of rigidity quantified and measured, in an array of species from the grass and horsetail families. Common features of hollow-stem construction in these two phyletically distant groups of plants may well provide examples of convergent evolution.