Cladophora spp.
Chlorophyta, Cladophoraceae
Authority: Kützing
Hawaiian name: none
Characteristic feature: Grass green filamentous seaweed.
Description: Plants filamentous, monosiphonous, profusely to sparsely branched, composed of multinucleate cells. Growth by apical and intercalary cell divisions. Branching pattern irregular, occasionally dichotomous, frequently secund, ultimate branches often sickle-shaped. In some species, rhizoids forming from basal corner of lower cells; attachment by modification of basal cell into simple or coralloid holdfast, or by rhizoids growing out from basal cell, or from entangled, fibrous group of rhizoids supporting several erect filaments; some species lacking holdfasts and appearing as floating populations. Plants often forming clumps or tufts, 1-50 cm tall. Bushy or tufted appearance; C. hawaiiana has fan-like fronds. May be slippery (C. flexuosa, C. sericea), soft (C. socialis), stiff (C. dotyana, C. luxurians, C. vagabunda), or spongy (C. laetevirens)
Habitat: In exposed turf, reef flat, benches, intertidal crevices, subtidal, low tidepools, and deep water. Also found floating.
Hawaiian distribution: All main Hawaiian Islands, including the Northwestern Hawaiian Islands.
Other: There are nine Cladophora species in Hawaiian waters, and many unidentified.
Cladophora sericea is a highly successful native invasive species, found to overgrow and smother coral and other algae during blooms on Maui.