 So, as we transition to the next group, seedless vascular, so what really is the difference between the first two? Between the seedless, non-vascular, and seedless vascular, what's the key evolutionary characteristic that's developed in this group? Vascular tissue. Very good. It's still seedless, so they're still reproducing using spores, correct? However, they've developed vascular tissue, so now they have their own transportation vessels. And so, this is where we have to look at the phylum names. I want to make sure that you guys are aware of the changes. So in the past, the two phylum, phylum lycophyta, and the previous name was pterophyta, again, the P.S. silent, so it's pronounced pterophyta. And in the book, in your text, monelophyta is the newly created name. Now what are we going to do, guys? I know I said we'll stick with monelophyta, but just looking at the literature, I think pterophyta is probably the name we want to stick with. There's more literature with still this name for the group as the representative as well as opposed to monelophyta, the newly created phylum division name. So again, let's go with lycophyta and pterophyta as the two phylum names for the seedless vascular plants. In the lab, we saw it as pterophyta as well, correct? And so the examples of these two, in terms of pterophyta, we are talking about what plant? The ferns. The ferns are the representative, just like the mosses were for the first group. The ferns are going to be the representative for the seedless vascular plants because they are more species of ferns than any of the others. The lycophyta, the club mosses are a smaller group, but we'll use the ferns as the representative to talk about, again, means of reproduction, alternation of generation in terms of the life cycle. So in terms of means of reproduction, what structures are they going to be using? Spores. Again, guys, once it's seedless, we're dealing with spores as opposed to seeds. So the first group, the seedless, reproduced by using spores. Second group, seedless vascular, also reproduces by using spores. But now we have the vascular tissue. Alternation of generation. Gametophyte and sporophyte, it alternates. All plant groups do. But if we're talking about the ferns, what's the dominant generation, yes? The sporophyte. We're going to put that in red. So again, folks, if we're talking the seedless vascular, the dominant generation is a sporophyte generation. When we're talking seedless non-vascular, dominant generation gametophyte, very important. So the gametophyte was dominant, now the sporophyte is dominant, and now we're completely on land, no dependency still to really water, because we have the sporophyte generation dominant, and the gametophyte grows independent of the sporophyte as a bisexual gametophyte that has both the male and female structures on the gametophyte generation. If you remember again from lab, we had that heart-shaped gametophyte as a representative of the ferns, yes? And so the male structures would be called again, what? Anthorhidia, female, archegonia, and the fusion of the sperm and egg creates the sporophyte that then grows independent of the gametophyte, and the cycle continues in the seedless vascular. Now as far as the vascular tissue, which has now evolved, and they able to transport materials around the plant, what are the two vascular tissues called? Yes? Fluem, very good. Thank you. So xylem, which conducts water and minerals, okay? Not just water, but water and minerals, obviously from the soil into the root system and up to the leaves where it's needed for photosynthesis. And then the phloem, the next transportation vessel, conducts sugars, we say, and other organic nutrients that are manufactured in the leaves from photosynthesis and transported to other areas of the plants, namely the root system, but there are times that it's stored in the stem as well, modified stems. Okay, so this is the vascular tissue that's evolved that is now going to show up in the seedless vascular plants, and of course the most advanced plants on the planet, the seed vascular plants, or seed plants, the vascular is understood, they normally just call seed plants because the vascular tissue is understood.