Stream macroalgae of Hawai`i: an identification guide - Hawaii.gov

Stigeoclonium
Classification: Chlorophyta (Family
Chaetophoraceae)
General habit: branched filaments forming feathery
tufts or expanses, yellow-green to grass-green in
color, not enclosed in mucilage, attached to
submerged rock or vegetation in streams
Species in Hawai‘i: S. amoenum, S. falklandicum, S.
fasciculare, S. flagelliferum, S. lubricum, S.
nudiusculum, S. pachydermum, S. segarare, S.
setigerum, S. stagnatile, S. subsecundem, S. tenue,
S. variabile, Stigeoclonium sp.
Island distribution: Kaua‘i, O‘ahu, Maui, Hawai‘i
Distinguishing features: branched filaments,
branches can be arranged opposite, alternate, or
sometimes dichotomously, filaments tapering to a
blunt point or a long hair, chloroplast plate-like and
encircling the cell (especially visible along the main
axis), not as much distinction in the diameter of the
main axis versus the branches (compared with
Cloniophora)
Compare with: Chaetophora, Cloniophora
35
A. An epilithic tuft of Stigeoclonium as viewed
under a dissecting microscope. Scale bar = 0.5cm.
B. Branched filaments viewed under a compound
microscope. Scale bar = 50µm. C. Main axis of a
plant showing the plate-like chloroplasts. Scale
bar = 30µm. D, E. Branching patterns of some
Stigeoclonium viewed under a compound microscope.
Scale bar = 50µm (D), 80µm (E).