More marine plants

Blue green algae, or Cyanophyta, or Myxophycease

a. Not too abundant or significant except in specialized, local areas, where it can often be extremely abundant and dominate an environment.

b. Contains phycocyanin, which imparts the bluish-green color to the plants.

c. Oldest known fossils of living organisms, dating more than 2 billion years old.

d. Cell walls are composed of chitin (CHON) instead of cellulose (CHO).

e. Reproduction mainly by asexual fission.

f. Trichodesmium erythraeum, a free-floating blue-green alga that is actually colored slightly red, occurs in vast numbers in the Red Sea, thus imparting the name to that body of water.

Green algae, or Chlorophyta, or Chlorophyceae.

a. Green color comes from chlorophylls alpha and beta. These plants contain carotenoids (yellows and oranges) and other pigments but in insufficient concentrations so that they are masked by the abundant chlorophyll pigments.

b. Cellulose walls, some encrusted with calcium carbonate, thus contributing significantly to the lime deposition in warmer seas.

1). Halimeda spp. contributes significantly to coral reefs, even though it is a green alga and a plant.

2). In these forms, the joints are uncalcified to allow for flexibility in the plants.

c. Isomorphic alternation of generations, in which the different stages in the life cycle of the plants are identical in external morphology.

d. Ulva spp. Described by Linnaeus in 1753; commonly called sea lettuce (U. lactuca), looking much life a leafy green lettuce although the color is generally a bit more translucent. It is a common intertidal and subtidal plant.

e. Chlorella spp. Much of the work done on the relationships between available light, chlorophyll, and the light part of the photosynthetic reaction was done on this genus.

f. Enteromorpha spp. These are slender, hair-like, hollow, tubular algae. They are especially prevalent on boat hulls, buoys, and piers, being very tolerant to changes in salinity (euryhaline). Related to Ulva is Enteromorpha in which the leaves have been squished flat so that the opposite walls are contiguous instead of having a hollow space between the walls.

g. Codium spp or spongeweed.

1). Codium fragile, or Dead Man's Fingers, is a drooping, spongy, olive green plant with a thick, pencil-sized, dichotomous branches. It can grow up to 1 m. or 3' tall.

2). The species found in the Sea of Cortez, or the Gulf of California, is rope-like, up to 10 m or 30' long. It is often found just rolling around in cracks along the rocky bottom.

h. Green algae are sun plants, occupying the upper littoral zones in depths shallower than 10 meters. They do best under conditions of bright lights.