DISSERTATION RESEARCH: Systematics, Evolution, and Biogeography of Lepechinia (Lamiaceae)

薄荷科(Lamiaceae)薄荷科(Lamiaceae)是一类开花植物，以提供用于烹饪的草药和用于园艺的观赏植物而闻名。许多野生物种也给美国的风景带来了色彩。在加利福尼亚州，一组薄荷属植物生长在被称为加州植物省的地区，该地区从俄勒冈州南部延伸到巴哈北部。该项目将使用Lepechinia和化石的DNA序列来确定加州植物区系省的起源。额外的DNA序列将被用来确定Lepechinia与其他薄荷组的亲缘关系有多密切。最后，DNA数据将被用来评估细粒棘藻的形态和繁殖系统在进化过程中发生了怎样的变化。加州植物区系省有许多世界上没有的植物物种。由于它的高度多样性和独特的物种集合，人们对了解它存在了多久以及它是如何形成的一直很感兴趣。Lepechinia和它的近亲鼠尾草(一种熟悉的园林植物)可以帮助确定植物区系的年龄。这项研究的初步结果表明，加州的Lepechinia和Salvia分支起源于1000万到2000万年前，可能来自生活在更南边的祖先。

Systematics, evolution, and biogeography of Lepechinia (Lamiaceae)AbstractThe mint family (Lamiaceae) is a group of flowering plants that is well known for providing herbs used in cooking and ornamentals used in gardening. Many wild species also colour the landscape of the U.S. In California, a group of mint species in the genus Lepechinia occur in the area known as the California Floristic Province, a region extending from Southern Oregon to Northern Baja. This project will use DNA sequences of Lepechinia and fossils to determine when the California Floristic Province originated. Additional DNA sequences will be used to determine how closely related Lepechinia is to other groups of mints. Finally, the DNA data will be used to assess how the morphology and breeding system of Lepechinia have changed during evolution. The California Floristic Province has many plant species that occur nowhere else in the world. Because of its high diversity and unique set of species, there has been considerable interest in understanding how long it has been in existence and how it formed. Lepechinia and its close relative Salvia (a familiar garden plant) can help to determine the age of the flora. Preliminary results of this study show that the California clades of Lepechinia and Salvia originated between 10 and 20 million years ago, probably from ancestors that lived farther to the south.