Chorda filum (Linnaeus) Stackhouse

Catenella caespitosa

Description: Thallus cylindrical, dark brown, to 10 m long (mostly 2-6 m when mature).  Frond unbranched, 5mm wide; parenchymatous, differentiated into a cortex, medulla and small celled epidermis; elongate medullary hyphae present; solid, becoming hollow in older plants.  Frond covered by clavate unicellular paraphyses and colourless hairs; attached by a discoid holdfast. Unilocular sporangia formed among paraphyses over the surface of the frond.  Fronds often wound together in rope-like masses.
Habitat: Grows on smalls stones and gravel in the lower intertidal and shallow subtidal; sometimes epiphytic.

Species list

Photographs © M.D. Guiry