Algae belongs to Thallophyta, which are non–vascular plants Thallophyta – Algae: The term algae refer to many types of aquatic, photosynthetic organisms. Algae are simple and green, growing as scum in watery places like ponds, puddles, lakes, ditches, drains, wet soil, wet walls, sea shores, in snow and in hot water springs.
They also grow symbiotically inside the body of the other plants. Often scientists classify these organisms along with plants, as they possess chlorophyll and distinct cell walls. They are considered "simple" because they lack the distinct organs of higher plants such as leaves and vascular tissue.
Algae have chlorophyll, the green pigment in their cells, which helps photosynthesis. In addition, some algae have an additional pigment giving the plants a different color. Algae are, therefore, named after the color they show: (i) Green algae: Chlamydomonas (unicellular), Spirogyra (filamentous), (ii) Blue–green algae: Nostoc, Anabena, Oscillatoria, (iii) Red Algae: Polysiphonia, (iv) Brown algae: Fucus, Laminaria (commonly called kelps). We obtain iodine from kelps, (v) Golden brown algae: Diatoms.
Bryophytes are commonly referred as mosses. Photo courtesy: Charles Baughman
Bryophytes are a group of simple and primitive plants. The division Bryophyta (Gk. Bryon = moss; phyton = plant) consists of about 25,000 species. The Bryophytes comprise of mosses and liverworts. From the view point of their evolution the Bryophytes stand at level higher than that of algae but lower than that of pteridophytes and seed plants. They are basically terrestrial forms, but require the presence of water for completing the life cycle. Hence, they are commonly described as amphibians of the plant kingdom.
Bryophytes lack typical vascular tissue, i.e., xylem and phloem from their gametophytes and sporophytes, and therefore, water and food are transported from cell to cell. Since there are no true roots, their cells absorb moisture directly from the ground or the atmosphere. Thus, they survive only in moist places.