—88— 



clearly. If several leaves be mounted in water, some will nearly 

 always be turned so as to show them in profile. This is ren- 

 dered easier by the fact that in many species the edges of 

 the leaves are rolled in (involute) in the upper part so that the 

 leaves are tubulose. The upper leaf cells are elongated-rectan- 

 gular, oblong-linear, quadrate or elliptical, according to the species; 

 toward the base they are elongated-rectangular. Those at the 

 basal angles are much enlarged and inflated, and are often of a 

 different color from the others (Fig. 3, lower portion). This last 

 character distinguishes the Dicranums from the allied genera and 

 species except Campylopus, in which the seta is curved and the 

 capsule pendent. Many of the species have the cells communi- 

 cating by pores, as shown in the upper part of Fig. 3. Such cells 

 are called porose or pitted. The protoplasm of the adjoining cells 

 communicates through these pores. These pores are very helpful 

 in determining the species. 



While there are 20 species of Dicranum found in the United 

 States north of Virginia and east of the Mississippi, there are only 

 five that are likely to be found by the great majority of our read- 

 ers. One of the most common and conspicuous is the broom moss 

 (D. scopariiim), so called because its leaves all point one way in 

 a manner that reminds one of a hair-broom or counter-brush.* 

 This is often used by florists and other merchants to form banks 

 of dark green in their windows. It can be found almost any- 

 where in the woods, on the ground, roots of trees, and rocks. It 

 is much the coarsest-appearing of the common species that have 

 curved capsules. A reference to the figures will give all further 

 details necessary for the identification of this species. 



The wavy Dicranum {D. undidatum) also grows on the 

 ground and rocks, but is the largest of the five species, and is at 

 once distinguished in the field by its beautiful silky, strongly un- 

 dulate leaves and clustered capsules. That is, it has several cap- 

 sules with setae inclosed in one cluster of perichaetial leaves (peri- 

 chsetium). The leaf cells are elongated and porose, like those of 

 the broom moss. 



The fuscous Dicranum {D. fuscescens) grows on rotten wood, 

 and is the only other common Dicranum with a curved capsule. 

 It is easily distinguished from the preceding species by its smal- 

 ler size, more delicate appearance, and leaves not undulate but 



*Fide Mrs. E. G. Britton in the New York Teachers' Monograph, Vol. 

 No. 2. 



