66 
THE SEAWEEDS 
bb. Receptacles terete annulate or two-edged, 
b@set with small scattered teeth . . S. globula?'iae folium , 
S. vest it urn , 
8. rhynchophorum . 
8. Gunnianum , 
8. grande , 
S. undulatum 
bbb. Receptacles triquetro-prismatic with 
prominent acute-angled edges. 
c. Not armed with teeth 
cc. With small teeth 
ccc. Sharply serrate 
aa. Bracteating leaves little different from the 
others 
8. ensifolium , 
S. erosum. 
8. lacerifolium, 
S. biforme . 
8. tristichum, 
8. Amaliae. 
S. membranaceum. 
I append descriptions of the three species as yet known from South 
Australia. 
Sargassum bract eolosum J. Agardh. 
Common eaulis short rounded, rachides of the branches triquetrous, 
branchlets retrofract (bent downwards). Leaves emerging from the plane 
surfaces, coriaceous, of a dark chestnut colour when dry, the lowest up to 
10 cm. long and 2.5 cm. wide, oval to oblong-lanceolate, petiolate, with mid- 
rib, some obsoletely toothed, others quite entire. The receptacles in a long 
panicle (to 60 cm.), with extremely numerous leaves or bracts which are 
very narrow and nerveless — about 2.5 cm. long. Vesicles often wanting, 
when present smaller than a pea, obovate-spherical and obtusely mucronate. 
Receptacles minute, single or few in the axils of bracts, rounded-oblong and 
unarmed. 
Tasmania and southern coasts of Australia. 
Sargassum lacerifolium (Turn.) C. Agardh. 
Axis sharply four-sided, flexuous, pinnately compound, 60-90 cm. long. 
Branches reflexed at their insertion, springing from the flat side of the 
stem. 15 to 30 cm. long. Leaves of two kinds, those at the base of each 
branch, lanceolate or linear lanceolate, 2.5 to 10 cm. long, 6 to 12 mm. wide, 
midribbed, deeply and sharply inciso-serrate or lacerate; those above (or 
“bracteate”) very narrow-linear, sharply serrate, with or without an obsolete 
midrib, 2.5 to 3.8 cm. long, 1 to 2 mm. wide. Vesicles few, one at the base 
of each branch or branchlet, on a flattened petiole, ovoid or subglobose with 
a narrow wing-like border, and crowned with a nerved and serrate leaf. 
