. II II A II AND-: I 7 



Plants of dry situations, small. Leaves with long white 

 awns, .... Awned Hair-cap (/>. pilifrrum Schrel>.) 



Plants larger, leaves without white awns, 4. 



Plants of lowlands without felted radicles 



Juniper Hair-tap, (/'. ju>iip< ( rinitm Willd.). 



Plants of alpine or suhalpine regions; steins covered with 

 a dense felt of radicles, Erect Hair-cap (/'. StrU (urn Banks). 



THE POGONATUMS 



THE Pogonatums differ from the Hair-caps mainly in the 

 cylindrical capsules, not square or angular in section. 

 The Slender Pogonatum is probably the most common 

 of our species. It grows on bare moist banks of clay or loam 

 where other plants have not yet obtained a foothold. The plants 

 do not grow close together as with most mosses, but singly and 

 scattered, the soil between them being covered with green felt- 

 like protonema. All mosses grow from just such green felt; the 

 spore germinates and grows into the protonema and a branch 

 of the protonema develops into the moss plant. After the 

 moss plant proper has developed, the protonema usually dis- 

 appears. In the Slender Pogonatum, however, the protonema 

 is persistent and plays an active part in the nutrition of the 

 plant, seeming to perform the function of leaves, for the leaves 

 on this plant are very few and short as compared with the 

 allied species. This is well illustrated by the figures, the 

 shaded upper portion of the leaf being the only part that con- 

 tains chlorophyll and therefore the only portion that performs 

 the functions of a leaf. These marked and interesting modifica- 

 tions may be due to the fact that this moss grows <>n freshly dis- 

 turbed earth and by this method is enabled to fruit befoi 

 competitors for the space are able to develop. The capsules 

 mature in late autumn. 



In woods and shady places, especially in elevated regions, 



the Alpine Pogonatum is common. It is a- ognized by 



its larger size and longer curved capsule with long beaked oper- 

 culum. The leaves, also, are much longer and more slender. 

 Without the sporophyte the Alpine Pogonatum is most likely to 



be mistaken for some of the Hair caps. Its capsules mature in 

 June or early July. 



The Urn-like Pogonatum grows in woods and shady pi 



ins. It is not uncommon and in some 

 localities may be even more common than either of the B] 



