162 



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 flat 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 ^4-^/2 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 l / 2 -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 

 and the roothairs are brown 

 while in Blasia they are white. 

 The dark dots at the base of 

 the lobes distinguish Blasia 

 from Pellia and from all other 

 plants likely to be confused 

 with it. Moist springy road- 

 sides are favorable places 

 for Blasia. 



FIGURE 88. Blasia pusilla. a. 

 Fertile plant in August natural 

 size, showing capsule in position. 

 At the side is shown the capsule 

 removed from the thallus. b. 

 Sterile plant with flask-shaped 

 bodies which produce gemmae. 



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 setae bearing the open 

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



