1 64 



MOSSES WITH A HAND-LENS 





open capsules bear a tuft of " elater-bearers " at the end of the 

 valves as in Metzgeria^ For convenience they may be divided 

 into two groups, the first with thallus narrow, about -^ to 

 iV inch wide, and the second with 

 thallus ^ to ^ an inch wide. There 

 is little danger of confusing the plants 

 of the first group with other plants, 

 except perhaps. Metzgeria or Riccia 

 Auitans, in which the branching is dis- 

 tinctly dichotomous and the thallus 

 costate, and in Riccia the plants are 

 floating-aquatic. 



R. LATiFRONS Lindb. Thallus 

 palmately divided something like the 

 horns of a stag, about an inch long, 



FiGURB 91. Thallus of end branches tV to ^ inch long, 

 P. Neesiana and portion of 1, , , . , ■ , /tm 

 thallus viewed from the about jV "ich Wide. The spores ripen 



ii^voIucre?'^'°lhe'''m*dYl'e '" ^P"^ ^"'^ ^^^ (Warnstorf). This 



figure shows the capsule of species nearly always grows on de- 

 P. epiphylla in position with , j j .t, 1 m -n ii 



involucre removed This is cayed wood and the next on soil. Both 



'p? XSr/ tt1"^^Ssui^ f^^"-- '^°°1 "^°ist situations, 

 have not developed at this R. MUETIEIDA (L.) Dum. is one 



two inches long, bipinnately 

 branched, often much more' regu- 

 larly and evenly so than indicated 

 in the figure; branches rather 

 narrower than in the preced- 

 ing; spores ripening about the 

 same time. Usually growing on 

 moist banks. 



There are three other species 

 within our range, but they are 

 scarcely to be distinguished with 

 a hand-lens. 



R. PiNGuis (L.) S. F. Gray of the second group is found 

 throughout our range on wet humus. It includes the R. sessilis 

 of Gray's Manual. 



Howe states that the larger forms when sterile may be mis- 

 taken for sterile forms of Pellia and that the "Distinguishing 

 marks are the pinnate instead of dichotomous branching, apices 

 rounded rather than emarginate, texture more rigid when dry 



Figure 92. Riccardia 

 multiUda, twice natural size. 



