u/SmokaCola0

Here is the life cycle for my hypothetical Selaginella (a lycophyte relative) descendant plants here. It is almost the exact same as real world Selaginella plants. Spores, which will give rise to the gametophyte generation develop in pea-like pods at the ends of leaves that are derived from the fusion of leaves of the ancestral strobulus. But unlike ferns and lycophytes, which produces spores that give rise to gametophyte plants that are able to produce both eggs and sperm, Selagionella exhibits something called heterospory. This means it produces two different kinds of spores: megaspores, which give rise to a Megagametophyte, a gametophyte that only produces egg cells, and microspores which give rise to a Microgametophyte, a gametophyte which only produce sperm cells. The gametophyte generation of Lycophytes and their relatives such as Selaginella remains understudied; they are cryptic and non-photosynthetic, and grow in close association with mycorrhizal fungus (it is unknown whenever this is mutualistic or parasitic), meaning it is difficult to cultivate them. For the Microgametophyte, the sperm will develop inside the microspore casing, and then are released when conditions are moist, such as when there is dew or after rain, and the sperm will then swim to receptive Megagametophyte. The larger Megagametophyte also develops mostly inside the megaspore casing, and when it is mature, the casing will split open at the top and the Megagametophyte produces rhizoids to absorb nutrients from the soil and the Archegonium will be receptive to fertillization. After ferzillization, an embryo will sprout from the gametophte to produce a new Sporophyte generation.

the second picture is just an alternative leaf shape

this is a sequel to some of my previous posts on Selagionella descendant plants here and here. Here are some hypothetical descendants of the Lycophyte Selagionella. The ancestral species (second slide) differs little from real-world Selagionella except for one key difference: each microphyll bearing branch will only branch seven times, then an axial bud will appear at the base of the branch and a new shoot will grow. This is a precursor to megaphylls. Spores are borne in terminal strobuli, and the gametophyte generation is small and non-photosynthetic, gaining most of their energy through energy reserves provided by the parent plant. In the descendant species, the microphylls of each seven-branching branch have fused into a megaphyll, and the spores are borne in long pea-like pods at the end of each leaf that are derived from the ancestral strobuli. When the spores are mature, these pods open and the spores are dispersed by the wind