Bryophytes

1. The First Plants to Live on Land Bryophytes By: Denise Cox and Carla Gonzalez

2. What are they? The word bryophyte is actually an umbrella name for three different paths of evolutionary lineage , three main types of nonvascular plants or plants lacking means of transporting fluid and nutrients internally: - Mosses - Hornworts - Liverworts Bryophyte comes from the Greek language bryon (tree moss, oyster-green) and fyton (plant). Bryophytes were actually the first plants to exist on land, and were the evolutionary stepping stone for vascular systems. The majority need to live in wet environments , though they are resilient little plants and are known survive in all types of climates.

3. Basic Bryophyte Structure • What you need to know: • Rhizoid: A slender root-like filament by which bryophytes attach to the soil and absorb nutrients – the roots • Gametophyte: The gamete-producing structure in a plant , otherwise known as the sexual phase of the life cycle– where the egg and sperm join in a plant `s life cycle • Sporophyte: in certain plants and algae, nonsexual phase (or an individual representing the phase) of the plant `s life cycle. – produces the gametophyte. • Seta : stalk of a moss capsule • Calyptra: In bryophytes, the calyptra (plural calyptrae) is an enlarged archegonia venter that protects the capsule containing the embryonic sporophyte • Capsule: : seed vessel

4. Let ` s See How They Make Babies What You Need to Know Gametophytes: the gamete-bearing individual or phase in the life cycle of a plant having alternation of generations Sporophytes: the spore-producing individual or phase in the life cycle of a plant having alternation of generations. Produces gametophytes Alternation of Generations : the alternation of two or more different forms in the life cycle of a plant or animal • Key Point to Remember • Although a bryophyte life is a cycle it is split in two parts, the first is the actual making of the bryophyte, and in the second stage, it is the development of the plant and preparation for reproduction (recall meiosis and mitosis)

5. Liverworts When a spore capsule is ripe, it bursts open along four “longitudinal axes” Simpler in structure than mosses Rhizoid composed of single elongated cell Have lobed, or divided leaves • Non- vascular • Plants • Same reproductive • Cycles Moss capsules usually have more complex opening mechanisms Mosses Hornworts • Smallest bryophyte • Gametophyte is saucer-shaped • Warm climates/ low, • shaded areas • sporophyte survives • after the gametophyte • has died. Rhizoid is multi-cellular Consist of stem and leaf structure