OF SOUTH AUSTRALIA. 
* 
247 
Subfamily Laurencieae (Harvey) Zanardini. 
LAURENCIA Lamouroux. 
Frond erect, terete and branched on all sides, or flattened, branching 
distichously ; a proper central axis very little conspicuous can be dis- 
tinguished toward the apex of the frond, with two strata, an interior of 
oblong-angulate cells, the central longer, smaller, shorter toward the circum- 
ference of the frond; and an exterior of rounded-angular cells disposed in 
a simple series. Cystocarps ovate-spherical, transformed out. of a ramulus, 
containing within a cellular pericarp open by a carpostomium, pear-shaped 
carpospores in the terminal joints of threads radiating from a central 
placenta. Tetrasporangia aggregated without order in a transverse zone, 
below the cortical cells of ramuli. Antheridia numerous included within a 
salver-shaped receptacle. The substance fleshy, cartilaginous. 
I. — Fronds terete. 
A. — Fertile superior ramuli diverse from lower and sterile ramuli. 
Laurencia heteroclada Harvey. 
Densely tufted, springing from creeping shoots ; frond livid-purple, 
terete, tough, 10 cm. to 20 cm. high. The lower sterile fronds closely set 
with lateral, often secund ramuli very straight and erect, filiform, with 
narrow axils. The fertile frond stipitate, with panicled or dendroid 
branches, dividing into many sub-patent secondary branches, which are set 
throughout with short, multifid, corymbose ramuli. Cystocarps ovate, 
sessile, borne on otherwise naked ultimate ramuli. Tetrasporangia apical 
in short, swollen ramuli. 
Covering the exposed edges of reefs at low water mark, spreading con- 
tinuously over wide spaces. 
Western Australia, South Australia, Victoria. 
B. — Fertile and sterile fronds similar in form, 
a. Filiform. 
Laurencia filiformis (C. Ag.) Montagne. 
Very slender, partially dichotomous, with elongate trailing branches and 
slim ramuli. Height 4 cm. to 15 cm. Colour rosy. Substance fleshy- 
membranaceous. 
Western Australia, South Australia (Eastern Bays), Tasmania. 
Laurencia Forsteri (Mertens) Greville. 
Stouter than L. filiformis with clavate filiform branches. Height 5 cm. 
to 15 cm., about 1 mm. thick. Colour rosy-purple, fading to yellow. Often 
epiphytic on Cymodocea. 
Common on all the south coast of Australia and Tasmania. South Aus- 
tralia (Encounter Bay, Holdfast Bay, Investigator Strait, Eastern Bays). 
Laurencia Casuarina J. Agardh. 
Ultra-setaceous, erect, with verticils of short ramuli. About 4 cm. to 
20 cm. high. 
South Australia (Port Elliot). 
