Salacia flavidula Watson, 2000

Stems up to 20 mm long, plumose, lower ahydrocladiate stem region short, perisarc thick, lightly fascicled by two or three stolonal tubes which may reach proximal node; proximal node a blunt hinge joint, hydrocaulus thereafter monosiphonic, segmented, hydrocladiate. Cauline internodes short, nodes transverse, deeply indented, a pair of opposite hydrocladia inserted on a wide shoulder-like apophysis above proximal node; two pairs of opposite or subopposite hydrothecae above hydrocladia, bases of hydrothecae not in contact across stem. Hydrocladial apophysis with a deep transverse proximal node and usually a secondary transverse node, sometimes a shallow V-shaped distal node.

Hydrocladium broad, inflated below hydrothecae, perisarc very thin, ending in a blunt distal tip; hydrocladium usually entirely lacking nodes, but if present, represented only by a faint constriction in perisarc.

Hydrothecae biseriate, alternate, sessile, frontal on hydrocladium, tubiform, narrowing to margin, adcauline wall convex, adnate to hydrotheca above, abcauline wall concave to almost straight, base of hydrotheca flat, concave or convex, partially overlapped by hydrotheca above. Adcauline margin of hydrotheca almost straight, a pair of lateral lobate cusps flanking margin, abcauline marginal embayment with a thin opercular valve. Hydrocladial coenosarc and hypostome of hydranth containing numerous large bean-shaped haplonemes, 22-28 µm long, 8-10 µm wide.

Hydranth with c. 24 tentacles, no abcauline caecum.

Colour: Brilliant lemon yellow in life; brown when preserved.