Читать книгу Pacific Seaweeds - Louis Druehl - Страница 50

Pacific Seaweeds

50 | Filaments

Filaments

Filamentous (thread-like) green seaweeds are characterized as being one cell wide and variously branched or unbranched. Some forms may remind the insensitive explorer of scum. Of all the seaweeds, these plants are the most similar to macroscopic freshwater algae. Their general appearance suggests a tight-knit assemblage, but microscopic features distinguish the 35-plus local species into a wide range of diverse green algal groups. They may have one or several nuclei per cell, the filament may be compartmentalized by cross-walls or not (making them essentially unicellular) and they have many types of life cycles. One life cycle incorporates both a filamentous and globular form (Derbesia, p. 57). The following examples express the morphological range of common green filaments.

Unbranched Filaments

Chaetomorpha (green excelsior) p. 51

Rhizoclonium (green fish line) p. 52

Urospora (Hanic’s green barrels) p. 53

A sand-swept patch of Chaetomorpha sp. (individual filaments on fingers).