82 



MOSSES WITH A HAND-LENS 



Capsules immersed or slightly emergent, plicate the whole 



length when dry 4- 



4. Empty capsule strongly contracted below the mouth when 



dry and empty, dark colored 5. 



Empty capsule only slightly contracted below the mouth, straw 



colored Ohioenss. 



5. Empty capsules dark red-brown on the folds, so deeply folded 



in many cases that the folds almost touch each other; 



calyptra without hairs strangulatum. 



Plants larger with hairy calyptras; capsules lighter colored 



and less deeply plicate sordidum. 



O. ANOMALUM Hedw. Rock O. (Figure 31) grows on rocks 

 in ratlier dense cushions, dark olive green or brown below; 

 calyptra hairy; capsule usually fully exserted, i6-striate, the 8 

 intermediate folds less distinct, oval-cylindric when moist, cylin- 

 dric when dry, abruptly narrowed to the neck. The peristome is 

 erect when dry, of 16 teeth, usually separate. Spores maturing 

 May-June. Not rare. 



This species will not be confused with any other species of 

 Orthotrichum, but may be confused with Ulota Americana. The 

 latter has the dry capsule gradually narrowed into the long neck 

 and the teeth reAexed when dry ; besides it is almost black in 

 color except at the extreme ends of the stems and branches, and 

 grows in loose wide mats. Its spores 

 mature much later, July- September. 



O. Ohioense S. & L. (Figure 30) grows 

 in rather dense, small cushions, yellowish 

 green, brown below ; stems about i-inch 

 long; leaves oblong-lanceolate; calyptra 

 hairy, moist capsule immersed, oblong- 

 ovate, when dry slightly 8-plicate, cam- 

 panulate, becoming more narrowed with 

 age, straw-colored; peristome of 8 double 

 teeth, strongly reflexed when dry. The 

 spores mature in early spring (April). 

 Common on trees. , When sterile it is a 

 difficult matter to distinguish this from O. 

 10 strangulatum, but the straw-colored lightly- 

 plicate capsules are easy of recognition. 

 O. SPECiosuM Nees., the Smooth Orthotrichum, is perhaps 

 the largest of our species, being an inch to an inch and a half in 

 height, yellow-green above; leaves tapering, very acute. The 

 calyptra is large, hairy, campanulate; capsule oblong-cylindrical, 

 almost exserted, the upper leaves barely reaching the base, 

 smooth or barely marked with irregular ridges when dry; oper- 



FiGUEE 30. Orthotri- 

 chum Ohioense. Dry 

 and empty capsule. 

 Stoma. 



