- Mature thalli are typically between 20 and 70 cm tall.
- Mature blades are lanceolate to oblong with acute apex, can be branched or unbranched, 6-20cm wide
- Fleshy/crispy, 0.2-3 mm thick blade
- Yellow-green to red-purple in color
- Stipe is about 2-3 cm long, frequently bearing lateral bladelets
- Apophysis, the area of transition between stipe and blade, is flattened and fleshy
- Surface covered in bumpy outgrowths (papillae)
- 1 or 2 cystocarps per papilla, sometimes with spines
- Tetrasporanial sori borne at base of slender, elongate papillae with thin attenuating tips.
- Red cortex cells; 5-7 cell layers thick on each side with clear medulla inbetween
- Medullary cells vary in shape and size (1.5-24mm in width), can be very intricate filaments(see image to the left, ~ 1200 micrometers wide) (alagebase.org)
- Growth is multi-axial ( Abbot et al.1976)
Abbott, Isabella A. and Hollenberg, George J. Marine Algae of California. Stanford, CA: Stanford University Press, 1976