568 University of California Publications in Botany [Vol. 8 



to a small cylindrical connection at the base, acuminate or rounded 

 above, the margins of all bearing very prominent, rather distant spine- 

 like projections with more or less rounded angles above ; stipe flattened 

 almost to the base. 



Growing principally on rocks, just below extreme low water level 

 down to ten fathoms or more in depth. From Puget Sound, Wash- 

 ington, and probably considerably farther north, to southern Cali- 

 fornia (San Pedro). 



Setchell and Gardner, Phyc. Cont., VII, 1924, p. 7. Desmarestia 

 ligulaia var. Jierhacea Setchell and Gardner, Alg. N.W. Amer., 1903, 

 p. 247; Tilden, Amer. Alg. (Exsicc), no. 244; Collins, Holden and 

 Setchell, Phyc. Bor.-Amer. (Exsicc), no. LXXIX A (not B). Des- 

 marestia latissima Pease, P.S.B.S. Publ., vol. 2, 1920, p. 319 (in part). 



Desmarestia munda is a long and moderately broad plant, with 

 indistinct midvein, usually faint above, and lateral veins branching 

 and disappearing before reaching the margins. The texture of the 

 living plant is firm and its surface is smooth, shining, and usualty 

 free from epiphytes and epizoa. It is for this reason that we have 

 chosen the specific designation. Pease (1920, p. 319) has published a 

 Desmarestia latissima as of Setchell and Gardner and states that the 

 type is in the Herbarium of the University of Minnesota. We are 

 not responsible for the type, which we have not yet seen, but from the 

 description in Pease, conclude that it includes D. munda as we estab- 

 lish it, as well as a plant to which we did assign the provisional name 

 D. latissima. The latter is the plant to which we limit the name, D. 

 latissima: In our opinion, our D. latissirma is sufficiently distinct from 

 D. munda to justify keeping them separate. 



9. Desmarestia latissima S. & G. 



Fronds membranaceous, broadly expanded, 3-4 m. long, up to 12 

 dm. wide, sparsely branched, exceedingly fragile; branches similar to 

 the main axis, of one order only, or possibly at times a few small 

 secondary branches, abruptly tapering at the base to a very slender 

 connection with the main frond, rounded at the outer end, midrib and 

 lateral veins inconspicuous. 



Growing in quiet water in bays and on mud flats, in the upper 

 sublittoral belt. San Juan County, Washington. 



Setchell and Gardner, in Pease, P.S.B.S. Publ., vol. 2, 1920, p. 319 

 (in part). 



