Where semi-formal is a step down from formal, semi-casual is a step up from casual.kirt or dresses for women is allowed. Button-down dress shirts, sweaters or polo shirts are great for men and women. Men may also wear a necktie but for semi-casual it s not expected. For a casual affair such as church, dinner at a friend s home, yachting or casual dining, a nice jacket or sweater for men is best.
Home Â» Algae. Definition. noun, singular: alga. A group of photosynthetic organisms that in general possess pigments such as chlorophyll but lack true roots, stems and leaves characteristic of terrestrial plants. algal (adjective) Of, pertaining to, characteristic of, or relating to an alga. Supplement.
The Phaeophyceae or brown algae (singular: alga), are a large group of mostly marine multicellular algae, including many seaweeds of colder Northern Hemisphere waters. They play an important role in marine environments, both as food and for the habitats they form.