514 University of California Publications in Botany [Vol.8 



trichum Kuetz., Pogotrichum Reinke, Litosiphon Harv. and Corycus 

 Kjellm. We know of but one of these in our territory, viz., Punctaria. 

 Structurally the simplest forms of the Punctariaceae, as generally 

 understood, are almost monosiphonous. The more complex forms 

 usually included in the family are either filamentous and solid, saccate 

 or membranaceous. They agree in general in that the zoosporangia 

 and gametangia arise as transformed single surface cells, projecting 

 beyond the surface but slightly, if at all, but if projecting not accom- 

 panied by pluricellular paraphyses. They form fairly definite and 

 circumscribed sori. 



The Punctariaceae have for their type genus Punctaria Grev. whose 



type species is P. latifolia Grev. Their relation is closely with 



Striariaceae, on the one hand, and the Scytosiphonaceae on the other. 



This relationship is so close that it is largely a matter of convenience 



to separate them. From the Striariaceae they may be separated by 



the tendency of their fronds even in the simplest Desmotrichum 



species, to develop a membrane rather than a cylindrical frond. In 



case this distinction is made, Pogotrichum and Litosiphon, under such 



understanding, should be referred rather to the Striariaceae and to 



the neighborhood of Stictyosiphon. While the species of Desmotrichum 



and Punctaria are both supposed to have hairs, yet some of our Pacific 



coast species of Punctaria have no trace of hairs in adult plants. There 



is an absence of hairs also in the known species of Phaeosaccion and of 



Omphalophyllum, two genera usually referred to the Punctariaceae. 



The two genera just mentioned also lack specialized sporangial cells in 



groups and it may be found desirable to separate them and give them 



a family designation of their own. Neither of these genera have 



been detected as yet in our territory, so that we have no opportunities 



for careful study. Corycus of Kjellman is hollow and, so far as 



descriptions inform us, devoid of hairs in the adult stages. It is 



flattened, even if it is hollow, and seems to belong in the Punctariaceae 



on that account as well as agreeing with both Striariaceae and 



Punctariaceae in having circumscribed sori which do not project 



beyond the surface. 



The Punctariaceae differ from the Scytosiphonaceae in having the 

 sori circumscribed and, commonly, of regular shape. The Scyto- 

 siphonaceae have extensive, indefinite and confluent sori and, thus far, 

 have been detected only with gametangia. 





