Flat, strap-like leaves 2-4mm wide Rounded, smooth leaf tip Smooth rhizome Scars from well-developed leaf sheaths form a continuous ring around the stem Found on shallow reef flats

Linear strap-like leaves, 5-9mm wide Serrated leaf tipLeaf sheath is broadly triangular with a narrow base Leaf scars do not form a continuous ring around the stemFound on shallow subtidal reef flats and sand banks

Very long ribbon-like leaves 30-150 cm longLeaves with inrolled leaf marginsThick rhizome with long black bristles and cord-like rootsFound on shallow/intertidal sand/mud banks (often adjacent to mangrove forests)

Fine, delicate leaves up to 20cm long1 central veinBlack central vein splits into two at the rounded leaf tipUsually pale rhizome, with clean black leaf scarsFound on intertidal sand banks

Usually larger than Halodule pinifoliaTrident leaf tip1 central longitudinal veinRhizome usually pale ivory, with clean black leaf scarsDugong preferred foodFound on shallow/intertidal sand or mud banks

Small oval leaves that are hairy on one sideCentral vein on leaf with 9-14 cross veinsUsually found deeper than 10m in coral environments proximal to coral reefsOnly found in subtidal Australian waters (>10m) proximal to coral reefs

Small oval leaf blade 1-2.5cm long6-8 cross veinsLeaf hairs on both sidesLeaves usually longer than widerFound at subtidal depths (>10m)

Oval shaped leaves in pairs8 or more cross veinsNo hairs on leaf surfacePreferred dugong foodCommon early colonising speciesFound from intertidal to subtidal depths

Less than 8 pairs of cross veinsSmall oval leaves occurring in pairsWedge-shaped leaf sheathFound on shallow/intertidal sand flats

Fern likeLeaves arranged in opposite pairsErect shoot up to 15cm longFound at subtidal depths (>10m

Erect shoots 8-18cm longLeaves with 3 veins2-3 leaves at each nodeLeaves “whorl” around stemFound at subtidal depths (>10m)Endemic to Queensland, Australia

Cylindrical in cross section (spaghetti like)Leaf tip tapers to a pointLeaves 7-30cm longFound on shallow subtidal reef flats and sand banks

Short black bars of tannin cells in leaf bladeThick rhizome with scars between shootsHooked/curved shaped leavesLeaves 10-40cm longCommon on shallow reef flats

Cluster of ribbon-like curved leaves at the end of an erect stemRound, serrated leaf tipTough, woody rhizomes with scars from successive shootsVery coiled, branched rootsTypically found in rocky areas with strong reef crests