Family: Plexauridae
Common Name(s): Shelf-knob sea rod
Colony Form: Candelabrum or bushy mainly in one plane with branches arising near colony base; usually <60 cm but up to 1 m tall. Morphotype plantaginea with fewer, more slender branches.
Axis: Cylindrical in cross-section.
Branches: Few and separated to profuse and crowded; ~7 mm across, usually >50% colony height. Morphotype plantaginea with branches 20-25 cm long, 3-5 mm across.
Apertures: Hemispherical with lower lip; calices recognizable by diagonally upward protrusion. Rows of calices sometimes spiral along branches.
Mucus: Absent
Color: Ochre. Dries dark brown to tan. Light brown polyps.
Sclerites: Polyp armature: small flattened rods. Axial layer: purple spindles 0.13-0.5 mm long, with simple to laterally deformed ornaments. Middle layer: large transparent spindles to 2 mm long and usually thin, 0.09-0.2 mm across. Surface layer: dense torch-like clubs 0.13-0.35 mm long.
Habitat: Reef terraces and slopes with moderate wave exposure, from shallow water to 25 m in depth.
Distribution: Bahamas, South Florida, and throughout the Caribbean Sea.
Notes: The plantaginea morphotype is taller and bushier with longer branches. E. succinea grows in one plane but may vary in branch density from few and separated to many and crowded. It can also be confused with thinner colonies of E. mammosa; check the calices.
Similar Species: Eunicea mammosa; Eunicea palmeri
