Cephaleuros

Cephaleuros is a genus of the family Trentepohliaceae and the division Chlorophyta. It is a genus of parasitic thalloid green alga that overall comprises 14 species approximately. Members of the family Trentepohliaceae are epiphytic, which means they grow upon another plant or object merely for physical support. Such members are also found on tree trunks, damp woodwork, and shady leaves. Parasitic, which means organisms that cause diseases. Although Cephaleuros are categorised under the division of Chlorophyta, still they lack green colour. 

The common name of Cephaleuros is red rust, as they are responsible for the causation of red rust disease in tea plants, coffee plants, mango plants, etc. Some members of this genera may also grow in association with a fungus that leads to the formation of a lichen that does not cause any damage to plant tissues. Because lichens refer to the symbiotic relationship between algae and a fungus. 

Cephaleuros Word Meaning

According to the Oxford Dictionary, Cephaleuros is a genus that comprises of epiphytic and parasitic green algae that specifically includes the causative organism of red rust. Epiphytic means they grow on other plants to provide physical support. The specimens of this genus can vary from 8-10 mm in size. 

Characteristics of the genus Cephaleuros

Members of Cephaleuros species have epidermis with cuticles, palisade cells, showing thallus. They reproduce sexually by forming gametangia, and asexually by sporangiophores, or zoosporangia. Sporangiophores project outside from the upper leaf surface. Some of the members of the Cephaleuros like Cephaleuros virescens have filamentous cells across their body structure. They are found in tropical and sub-tropical regions worldwide. They also contain the photosynthetic organisms known as Green algae. The thallus structure of the Cephaleuros family is generally composed of a prostate system and an erect system that provide mutual support during growth and development. 

Cephaleuros virescens Causes

Being a member of the genus Cephaleuros, it is a parasitic alga that causes some serious diseases in plants and affects its productivity. These are aerophilic and filamentous green algae. Cephaleuros virescens is a parasite of guava (Psidium guajava) leaves and fruits in Hawaii, causing leaf and fruit spot diseases. It causes leaf spot disease of guava plants. These spots are reddish-black in a colour that is visible with naked eyes. Apart from guava, C. virescens also infects the crop of tea, coffee, and coconut plants by causing algal leaf spots or algal rust (red rust). The pathogen of this alga is usually dispersed through water or air. They cause infection by depositing their sporangia or thallus filaments over the surface of the leaves. Cephaleuros infections on tea or coffee plants have been called red rust. When the environment is favourable for their growth, zoospores are released from those sporangia, and symptoms become visible. The most favourable environment for their growth is moist and humid with little rainfall. 

Examples of Cephaleuros

Some of the species of Cephaleuros include C. minimus, C. pilosa, C. expansa, C. solutus, C. virescens, etc. All of these species have almost all unique features, division, life-cycle, mode of infections, and symptoms. But C. virescens is most commonly seen and causes diseases in all the continents of the tropical and subtropical areas. 

Conclusion

Cephaleuros is a member of the family Trentepohlia Ceae and the division Chlorophyta. It is a group of epiphytic and parasitic algae. The genus of Cephaleuros includes almost 14 different species. Among 14 species, Cephaleuros virescens is more common. Being algae, they also show a symbiotic relationship with fungus and lead to the synthesis of lichens. They cause infection in the leaves of tea, coffee, mango, and guava, leading to a decline in their productivity. Their common name is red rust. They cause symptoms including red to orange-brown spots over the surface, and beneath the leaves, that are visible with naked eyes. They are found in tropical and sub-tropical regions worldwide. They also contain the photosynthetic organisms known as Green algae. The thallus structure of the Cephaleuros family is generally composed of a prostate system and an erect system that provide mutual support during growth and development.