102 MOSSES WITH A HAND-LENS 



BLASIA. 



B. pusiLLA L. is one of the most common of the Thalloid 

 Scale Mosses having a distinct midrib ; the midrib is not, 

 however, quite so conspicuous as some of the books indicate. It 

 grows fiat on the ground when the plants are few and scattered, 

 but when crowded they become ascending and grow in thick 

 curly tufts like miniature lettuce. The plants are dark green, 

 or even purple, with very distinct almost leaflike lobes along 

 the sides, occupying from Yn-Yi the entire width of the thallus. 

 If the plants be held up to the light two dark dots will usually 

 be seen at the base of each lobe. These are peculiar structures 

 known as " leaf-auricles.'' The spores mature in early spring, 

 but in July and August the young capsules can be seen inclosed 

 in the end of the midrib in the female shoots. When ripe the 

 capsule is elevated on a seta J^-i inch in height. There is no 

 perianth except the broken tissue of the thallus. A fluffy mass 

 consisting of spores and elaters often remains for some time 

 in the center of the capsule. Flask-shaped bodies like those 

 shown in the illustration are usually abundant on sterile stems ; 

 these bear large numbers of gemmae. Pellia often grows mixed 

 with Blasia and as its midrib is frequently as plain as that of 



Blasia it may be confused with 

 it, but the margins of Pellia are 

 sinuate and less plainly lobed 



y^^ ''^^Sf^/^^f^^^^^ ^"'^ ^^ roothairs are brown 



iiP'^'' Mf^fw^ while in Blasia they are white. 



Vfy'p' „ p/'Vutr ^ "^'""^ dark dots at the base of 



the lobes distinguish Blasia 



„„ „, . . , from Pellia and from all other 



Figure 88. Blasia pusilla, a. 1., , t a 



Fertile plant in August natural plants likely tO be COnfUSed 



size, showing capsule in position. -^, ■^ lUnict snrino-v rnaH- 



At the side is shown the capsule ^Itll It. MOlSt sprmgy roao 



removed from the thallus. b. sides are favorable places 



Sterile plant with flask-shaped . -pi 



bodies which produce gemrnse. ^^"^ rilasia. 



PELLIA. 



p. EPiPHYLLA (L.) Corda., the Common Pellia, is one of 

 the commonest objects on moist banks. It should be sought for 

 early in May when the slender delicate setje bearing the open 

 .four-valved capsules are striking objects to one who is looking 



