EXERCISE 12: THE ALGAE

• Algae- a diverse collection of photosynthetic organisms that lack vascular tissues
• Seaweeds- often exhibit the highest level of organization and superficially resemble the higher plants of Kingdom Plantae
• Blades- leaf-like structures in seaweed
• Stipes- stem-like structures in seaweeds
• Holdfasts- root-like structures in seaweeds
• Thallus- is a term for the mass of cellular tissue forming a plant body without true stems, roots, leaves, or vascular system.
• Articulated: Calcified segments connected by uncalcified joints.
• Bladed: Flattened leaf-like thallus or thallus part.
• Branching: Alga with axillary divisions.
• Corticated: Pigmented cells (cortex) growing as an outer layer.
• Crustose: Grows flat along the substrate; crust-like.
• Filament: Thread or hair-like.
• Foliose: A sheet of cells; blade-like.
• Monostromatic: One cell thick.
• Distromatic: Two cells thick.
• Polystromatic: Many cells thick.
• Prostrate: Trailing on the ground; procumbent.
• Saccate: Sac-like.
• Stipitate: Having a stipe—a thick, stem-like structure bearing other structures like blades.
• Stoloniferous: Proliferating by vegetative branches that creep along the substrate and establish new plants.
• Tubular: Thallus made up of a tube of cells, hollow in center.
• Upright: In an erect position or posture; vertical or nearly so; pointing upward.
• Dichotomous- branching form characterized by forking in pairs
• Distichous: Branching on both sides of an axis.
• Irregular: Branching with no detectable branching pattern.
• Monopodial: Having a distinct main axis of continual growth and giving off branches.
• Pectinate: Having unilateral branching on one side of the axis.
• Percurrent: Extending through entire length of structure
• Pinnate: Feather-like branching.
• Reticulate: Net-like.
• Simple: Unbranched, undivided thallus or blade.
• Whorled: Radial branches attached at a common level on the main axis, or branches spiraling off the main axis.
• Basal disk- disk at base of a plant that attaches to the substrate
• Haptera: The network formed by multiple haptera clasping the substrate
• Boreal: Growing in northern, colder waters.
• Cosmopolitan: Found in many parts of the world.
• Tropical: Growing in near-equatorial, warmer waters.
• Temperate: Growing in regions between either tropic and its corresponding polar circle, in moderate temperatures.
• Intertidal: Lying between high and low tide levels, exposed at low tide.
• Subtidal: Below the lowest low-tide level.