Brown algae reproduce by fragmentation in which a part or fragment is detached from the parent plant & develop into a new alga plant. This is very common in Ascophyllum, Fucus & Sargasum. Propagules formation: Here specialized vegetative branches develop from the main axis & on detachment, the Propagules attaches into a suitable substratum & germinates into a new plant. e.g: Sphacelaria