Hi. Today we're going to open the door to the plants world. So first of all, we are going to define botany and what's the plant. Then we are going to see that two big groups of plants; the non-vascular plants and the vascular plants. Botany is defined as the scientific study of plants. Lynn Margulis define plants as liverworts, horworts, mosses, and vascular plants. This is the classification I'm going to use to explain you the big groups of plants. If you try to define a plant and you think of a plant, probably it comes into your head the idea that a plant is an organism with leaves, stems, flowers, seeds, and roots. Probably after this idea, it will come into your head also some exceptions. There are exceptions like for example, cactus, the cacti, they don't have leaves, or maybe the mosses that they don't have flowers neither seeds. They reproduce by spores. But all of them are considered plants because all of them share similar biochemistry and structures and cell structures. So since we are talking about cacti, let me introduce Helia Bravo Hollis. She was an important botanists who found out around 60 species 60 taxa of cacti in Mexico, and also she revised 59 taxonomic nomenclature of cacti. She had a huge work in botany of cacti, especially in field work and also inner volumes. So defining botany, another issue that is important is what happens with the algae. Algae can be considered as a plant or not. So they have similar structure and biochemistry as plants and some botanists think that it's better to include them in this group of plants but there are some botanist that consider they should be in another group because they have also some differences with the rest of the plants. So in this course, we are going to talk about algae especially in the videos related to aquatic ecosystems. Respect to fungi and lichen, which lichen is a symbiosis between fungi and an algae, they are both in the fungi kingdom, and we are not going to talk about them during the rest of this lesson because they are in another kingdom. So let us start with the first group of plants, the mosses, the hornworts, and liverworts. They are also called bryophytes. In fact, bryophytes is a word used for mosses, but also for these other two groups; liverworts and hornworts. These are non-vascular plants. Let me also introduce you a team of three women who have worked a lot with this group of bryophytes. These are Dr. Montserrat Brugues, Creu Casas, and Rosa Maria Cros. They are from the Laboratory of Radiology in the University Autonomous of Barcelona. Especially here in the picture you can see Creu Casas, who was the first woman who created this group. She has more than 200 papers related to bryophytes, and she was one of the first women to be a professor in a university in Spain. Inside the planti kingdom, we can find bryophytes, ferns, gymnosperms and flowering plants. The ferns reproduce with spores not with flowers. We can find ferns in many different types of habitats, shady habitas and also dry habitas. Ferns never produce root, so they are all herbs. Next group of vascular plants are the gymnosperms. In the group of gymnosperms, we can find cycads, ginkgoes and also conifers. The group of conifers is one of the gymnosperms groups of plants that is more distributed worldwide. We can find plants like pines or spruces. The conifers reproduce from a structure that it's called corn. Finally, we have the last group, which is the flowering plants also called angiosperms. Conifers and flowering plants are also called seed plants or spermathophites. One of the most noteworthy features of this group of plants, the angiosperms, is that we find a huge diversity of bodies. For example, we find plants like trees, shrubs, herbs, vines, burbs. It doesn't happen nowadays with groups of ferns or gymnosperms. So finally, we can divide angiosperms into groups. The monocots; like lilies, palms, arecales and orchids, and eudicots which are the rest of angiosperms. So we have arrived to the end of this video. Well, we have opened the door to the plants world, I hope you will explore it in the future