—39— 



with is the slender Pogonatum (P. tenue — P. brevicaule of many 

 authors). It grows on bare clayey soil of banks, roadsides, and 

 ditches. The plants do not grow close together but scattered, so 

 that they look like small green dots against the lighter color of 

 the soil. The stems are very short and simple, without branches ; 

 the leaves are few, 5-10, radical and very close to the ground, 

 serrate, with few, 8-12, lamellae. If the ground around the plants 

 be examined, it will be found to be covered with a green felt, the 

 protonema (rig. 1), which is composed of slender, green, alga-like 

 threads that spring from the germinating spore and later give 

 rise to the mature moss plant. In this species, contrary to the 

 general rule, the protonema lasts throughout the life of the plant. 

 The abundance and persistence of the protonema may account 

 for the small number of leaves and the reduced size of the plant, 

 as it doubtless does as much starch-making as many leaves could 

 do. The capsules are cylindric, nearly or quite erect, and are 

 covered with very minute wart-like projections called papillae. 

 The short-leaved Pogonatum of the New Jersey pine barrens and 

 southward is much like this species, but is easily distinguished by 

 its shorter entire leaves. The urn-like Pogonatum (P. urnigerum) y 

 is fully as common as the slender Pogonatum in the hilly districts 

 of New England. The stems are much longer, usually branched, 

 naked below and densely leafy above, without persistent proto- 

 nema. The leaves are serrate, but larger, with very many, 

 40-50, lamellae. The capsules are very much like those of the 

 slender Pogonatum. The alpine Pogonatum {P. alpinum), is 

 almost sure to be at first mistaken for a hair- cap because of its 

 large size, 2-6 inches in height. It is more likely to be met with 

 than its name indicates, as it is not uncommon in New England 

 on exposed places at an altitude of 1,000 feet or even less. It is 

 readily distinguished by its size, its smooth and inclined or 

 slightly curved capsule. Only those who are privileged to visit 

 our higher mountains need expect to find the hair-like Pogonatum 

 {P. capillar e). It is most likely to be mistaken for the urn-like 

 Pogonatum, from which it differs in its shorter capsule, nearly 

 simple stem, and in the terminal cell of the lamellae which is flat- 

 topped ; in the urn-like Pogonatum it is sharply rounded. The 

 leaves are also much more curled when dry. 



The common hair- cap mess is one of the few plants that have 

 an almost world-wide distribution. It is found in all parts of 

 North America, in Europe, and in Asia. 



