Spyridia filamentosa
Rhodophyta, Ceramiaceae
Authority: (Wulfen) Harvey
Hawaiian name: none
Characteristic feature: Branches covered with many soft, fine, short branches that create a fuzzy appearance.
Description: Plants usually less than 2 cm tall when in low turf mats, up to 18 cm tall in areas of good water motion; fastened by small discoid holdfast, lower portions of plants and lower branches tending to entangle; one to several erect axes, branching irregularly dichotomous or completely irregular, at times also alternate or unilateral; axes crisp, brittle, branching to 4-5 or more orders, the last orders short, becoming matted and giving plants fuzzy appearance; plants often look whitish or lightly calcified, but calcification from crustose coralline algae or sediment, not inherent in plants. Tetrasporangia spherical, 25-40 mm diam., with 1-2 gonimolobes seemingly simultaneously developed, with delicate, branched sterile filaments forming loose involucre around spore masses.
Habitat: Common on eroded coral in sandy areas, but occurring in sandy mud as well, in matted intertidal turfs on coral and basalt; mostly shallow subtidal to 10 m, often a dominant weedy species in mildly stressed habitats.
Hawaiian distribution: All main Hawaiian Islands, including the Northwestern Hawaiian Islands.
Other: The fine branches trap fine sediment, making the limu appear many different colors.