Plectonema

**Definition:** A form-genus of CYANOBACTERIA in the order Oscillatoriales. They are non-heterocystous but may carry out NITROGEN FIXATION under microaerobic conditions. Some smaller members have undergone transfer to the form-genus Leptolyngbya.

**Tree numbers:** - B03.280.650 - B03.440.475.100.650 - B03.585.880