Specimen #7: Pleurocapsa

Name: Pleurocapsa
Family: Hydrococcaceae
Collection Date: November 2^nd, 2011
Location: Hiram College Botany Lab, Algae Tanks
Collector: Katie Rumora

Key Used:

Prescott, G. W. (1970). How to Know the Freshwater Algae . Boston : WCB McGraw Hill .

1b. Plants microscopic, or if macroscopic with cellular structures and branches not clearly visible to the unaided eye; without whorls of branches clearly visible … 4

4b. Cells without chloroplasts, with pigments seemingly distributed and diffuse throughout the cell. Blue-green algae. Cyanophyta … 565

565b. Plants not filamentous; cells globular, rod-shaped, or angular from mutual compression, or forming cushionlike masses of isodiametric cells in which a suggestion of filamentous arrangement may be apparent … 619

619a. Plants attached; cells club-shaped or globular-angular isodiametric; gregarious, forming cushion-like masses or horizontal expanses, or solitary; epiphytic or growing on shells; cells usually showing endospores … 620

620b. Cells some other shape; gregarious, forming horizontal expanses which may show a slight tendency to elongate as short filaments, or as cushions … 622

622b. Plant mass in the form of a cushion with the cells arranged in vertical rows or as false filaments … 626

626b. Cells not enclosed by a thick sheath; plant mass usually macroscopic in well-developed thalli … 627

627a. Plant mass forming a flat layer or cushion … 628

628b. Thallus an encrusting growth with rhizoidal extensions on the ventral side, the upper or outer portion consisting of uniseriate or multiseriate branches, all very compact with sheaths fused together … Pleurocapsa 

Figure 1: Pleurocapsa 

 

Figure 2: Preserved Specimen of Pleurocapsa 

Description:

“Unicellular - pseudofilamentous; thallus creeping on the substrate (mainly on stones), crust-like or in a thin layer, composed of irregular groups of cells (chroococcacean state), from which grow irregular or radial rows of cells, sometimes irregularly branched; in several species are the pseudofilaments endolithic; rows of cells uni- or multicellular, enveloped by more or less thin, firm, sometimes lamellated and yellowish-brownish colored sheaths confluent together by their sides. Cells irregular, of different size, sometimes (in pseudofilaments) slightly elongated, with homogeneous or slightly granular content, sometimes with several prominent granules, bluegreen, pale blue-green or pinkish. Cells divide irregularly in different planes; enlarged cells from different parts of thallus divide sometimes in nanocytes. Reproduction by nanocytes. Type species and several other taxa known from marine littorals (surf or intertidal zones); freshwater species known usually from clear mountain streams or from the stony surf -zones of unpolluted lakes and reservoirs, worldwide. Most species grow on limestone substrates” (Pleurocapsa Thuret in Hauck, 1885: 555).

Links:
http://www.algaebase.org/search/genus/detail/?genus_id=43068
http://www.discoverlife.org/mp/20q?search=Pleurocapsa

References:

Pleurocapsa Thuret in Hauck, 1885: 555. (n.d.). Retrieved Novemeber 10 , 2011, from Algae Base : http://www.algaebase.org/search/genus/detail/?genus_id=43068

Prescott, G. W. (1970). How to Know the Freshwater Algae . Boston : WCB McGraw Hill .