Phylum: Phaeophyta

Class: Phaeophyceae

Order: Desmarestiales

Family: Desmarestiaceae

Desmarestia herbacea (Lamouroux)

 

Description:  This plant is erect, up to 2m. high, flattened, 1-2 cm. wide, tapering abruptly to a short cylindrical stipe with a discoid holdfast.  The plant has 3-4 orders of branches from a percurrent axis; branching opposite; base of branches stipitate.  The main axis and branches have a conspicuous thick percurrent midrib, and branch apices are densely clothes with acute hairs.

 

Habitat:  On rocks in the lower intertidal zone and upper subtidal zones.

 

Pacific Coast Distribution:  Alaska to Mexico.

                                                                                      Robert Scagel, 1972

 

The highly branched axis of D. herbacea.  Photo courtesy CEMAR

D. herbacea at the base of a Laminarian

 

 

Phylum: Phaeophyta

Class: Phaeophyceae

Order: Desmarestiales

Family: Desmarestiaceae

Desmarestia intermedia (Postels and Ruprecht)

 

Description:  This plant is dark brown in colour, up to 60 cm. high, very profusely branched, wiry; branches mostly compressed, about 1.5 mm. wide except near the base, where the main axes are up to 5 mm. wide and cylindrical.  Branching is fasiculate below, mostly alternate above, occasionally opposite.

 

Habitat:  On rocks in the upper subtidal zone.

 

Pacific Coast Distribution:  Bering Sea to Oregon.

                                                                                      Robert Scagel, 1972

 

The wiry branches of D. intermedia

 

 

Phylum: Phaeophyta

Class: Phaeophyceae

Order: Desmarestiales

Family: Desmarestiaceae

Desmarestia munda (Setchell and Gardner)

 

Description:  This plant is yellowish brown to dark brown in colour, rigid, 4-8 m. tall, ligulate, 2-10 cm. wide, with a percurrent sparsely branched axis with short laterals and spines in opposite pairs throughout the length of the plant.  The ligulate main axis tapers to a short stipe, which cylindrical at the base and merges into a stout discoid holdfast.  The branches are stipitate at the base.  There is conspicuous midrib on the stipe and lower parts of the plant, which becomes less conspicuous above and ultimately appears only as a delicate vein.

 

Habitat:  On rocks in the lower intertidal and upper subtidal zones to a depth of 10 fathoms.

 

Pacific Coast Distribution:  British Columbia to Mexico.

                                                                                      Robert Scagel, 1972

 

Branched axis of D. munda