Dissertation Research: Integrating Phylogenetic and Taxonomic Studies of the Commelinaceae using Molecular and Morphological Data

开花植物Commelinaceae由大约41属和650种多年生或偶尔一年生草本植物组成，分布在全球温带和热带地区。Commelinaceae也被称为“蜘蛛草家族”，包括熟悉的栽培观赏植物，如Tradescantia和Zebrina（蜘蛛草和流浪犹太人）。常见的野花包括各种各样的毛茛属（日花）和其他属。数量更多但不太为人所知的是这个科的热带属，其中一些正由研究生克里斯托弗·哈迪在康奈尔大学杰罗德·戴维斯博士的指导下进行研究。该项目的目标是对原产于中美洲和南美洲热带森林的三个密切相关的属进行系统发育和分类研究。这些属分别是耳蜗属、地根属和一个由估计6至7个新种组成的未描述属。耳蜗科的植物在commlinaceae中是不寻常的，因为它们主要以附生植物的形式生长在森林冠层的高处，有些具有“水箱植物”的习性，在营养上类似于凤梨科。耳蜗属植物还拥有该科中已知的最大的花。地根花主要由五个亚马逊种组成；地根草是一种低矮的根状植物，其主要特点是在土壤表面和叶子下面开花。最后，未描述属的植物是莲座林下植物，通常具有深紫色的叶子，上面有明亮的白色纵条纹。本研究的系统发育部分的目的是更好地了解这三个属和13到14个物种彼此之间以及与该科其他成员之间的关系。通过分析花和营养结构的变化以及细胞核和叶绿体基因的DNA序列，可以推断出系统发育关系。这一系统发育中的进化分歧序列将为该群体中大型和奇怪的花形式的进化建立假设。该组的分类学处理（专著）将包括几个属的所有物种的关键字和新的或更新的描述。

9902015Davis and Hardy The flowering plant family Commelinaceae consists of approximately 41 genera and 650 species of perennial or occasionally annual herbs distributed throughout temperate and tropical zones worldwide. Known also as the "Spiderwort Family", the Commelinaceae includes familiar cultivated ornamentals such as Tradescantia and Zebrina (the spiderwort and wandering jew). Common wildflowers include various species of Commelina (dayflowers) among other genera. More numerous but less well known are the tropical genera of the family, some of which are being studied by graduate student Christopher Hardy under the direction of Dr. Jerrold Davis at Cornell University. The goals of this project are to conduct phylogenetic and taxonomic studies within the family on three closely related genera native to the tropical forests of Central and South America. These genera are Cochliostema, Geogenanthus, and an undescribed genus consisting of an estimated six to seven new species.Plants of Cochliostema are unusual for the Commelinaceae in that they are found growing primarily high in forest canopies as epiphytes, some with the "tank plant" habit that resembles bromeliads vegetatively. Plants of Cochliostema also possess the largest flowers known in the family. Geogenanthus consists of five primarily Amazonian species; low growing and rhizomatous, plants of Geogenanthus are distinguished primarily by their unusual habit of bearing flowers at the soil surface and beneath the leaves. Finally, plants of the undescribed genus are rosette understory plants often possessing leaves with deep purple beneath and a brilliant white longitudinal stripe above. The objective of the phylogenetic component of this research is to better understand how these three genera and thirteen to fourteen species are related to one another and to other members of the family. Inferences of phylogenetic relationships will be obtained by analyzing variation in floral and vegetative structure in addition to DNA sequences from nuclear and chloroplast genes. The sequence of evolutionary divergences in this phylogeny will establish hypotheses about the evolution of the large and bizarre floral forms in the group. A taxonomic treatment (monograph) of this group will include keys and new or updated descriptions of all species of the several genera.