Perennials develop their roots, stems, leaves, flowers and seeds all in the first year. The brown, red, and green algae are commonly known as seaweeds. All algae contain chlorophyll and live in the water. Seaweeds contain cellulose and are classified as plants. Many have a stemlike structure that holds it to rocks.
Green plants make their own food by photosynthesis.
That is, carbon dioxide combines with water to yield glucose and oxygen. Plants that have soft and green stems are know as herbaceous plants. The stems contain chlorophyll and so make food. Typical conifers are pine, fir, yew, redwood, and spruce.