Purpureaphyta

From Coriapedia, the alien wiki

Moonweeds, also known more simply as purple plants are mainly multicellular organisms, predominantly photosynthetic eukaryotes of the kingdom Purpureaphyta.

Most purple plants obtain most of their energy from sunlight via photosynthesis by primary purpuroplasts that are derived from endosymbiosis with purpureobacteria. Their purpuroplasts contain purpureophylls a and b, which gives most of them their purple color. Some groups and species are parasitic(either infecting anomalotheres or other moonweeds), heterotrophic(as is the case of the snapmouth herbis), radiotrophic or dhusiotrophic(similar to a mycotroph) and have lost the ability to produce normal amounts of purpureophyll or to photosynthesize, but still have anthoids(equivalent to flowers on Earth), carpoids(equivalent to fruits on Earth), and xylospermae(equivalent to seeds on Earth). Moonweeds are characterized by sexual reproduction and alternation of generations, although asexual reproduction is also common.

There are about 320,020 species of moonweeds, of which the great majority produce xylospermaes. Purple plants provide a substantial proportion of the world's molecular oxygen, and are the basis of most of Corias's ecosystems. The scientific study of moonweeds and similar organisms is known as astrobotany, a branch of astrobiology.

Terrapurpureaphytes
Main article: Terrapurpureaphyte

The moonweeds that are the most dominant are the multicellular land moonweeds, called terrapurpureaphytes. Terraapurpureaphyta include the vascular moonweeds, such as featherheads, tholifers and flowering moonweeds. They also include the archaeopurpureaphytes, of which paluses and bloodworts are the most common.

All of these have mirukaryotic cells with cell walls composed of cellulose, and most obtain their energy through photosynthesis, using light, water and carbon dioxide to synthesize food. About three hundred moonweed species do not photosynthesize but are parasites on other species of photosynthetic moonweeds. These are distinguished from purple algae, which represent a mode of photosynthetic life similar to the kind modern moonweeds are believed to have evolved from, by having specialized reproductive organs protected by non-reproductive tissues.

Archaeopurpureaphytes first appeared during the early Amphizoic. They mainly live in habitats where moisture is available for significant periods, although some species are desiccation-tolerant. Most species remain small throughout their life-cycle. This involves an alternation between two generations: a haploid stage, called the gametophyte, and a diploid stage, called the sporophyte. In archaeopurpureaphytes, the sporophyte is always unbranched and remains nutritionally dependent on its parent gametophyte. The terrapurpureaphytes have the ability to secrete a cuticle on their outer surface, a waxy layer that confers resistant to desiccation. In the paluses and candycorn-worts a cuticle is usually only produced on the sporophyte. Stomata are absent from bloodworts, but occur on the sporangia of paluses and candycorn-worts, allowing gas exchange.

Photosynthesis
Most moonweeds are photosynthetic, which means that they manufacture their own food molecules using energy obtained from light. The primary mechanism they have for capturing light energy is the pigment purpureophyll. All purple plants contain two forms of purpureophyll, purpureophyll a and purpureophyll b. The latter of these pigments is not found in the distantly related and not dominant heterotrophic blueweeds or dark algae.