342 BOTANY. 



Dicranum rhabdocarpum, Sulliv. — Densely casspitose ; stems dicho- 

 tomously branched; leaves erect, concave, elongate-lanceolate; nerve van- 

 ishing below the apex; areolation loose; of a light shining green; capsule 

 erect, cylindrical, regular, when dry 5- to 8-ribbed; no annulus; operculum 

 obliquely rostrate. 



Hab. — Mount Graham, Arizona., on rotten pine logs ; rare. 



Pottia Heimii, Hedw. — Tufted plants with flexuose oblong-lanceolate 

 leaves, serrated at the apex, with a plane margin and nerve ceasing below 

 the point; capsule oblong, and remarkable for the rostrate operculum adher- 

 ing to the columella beyond the mouth of the capsule. 



Hab. — Twin Lakes, on shaded ground. 



Didymodon rubellus, Bry. Eur. — Leaves intense dull green ; lower 

 ones invariably reddish, by which feature it is readily recognized. 



Hab. — Twin Lakes, on wet banks; not rare. 



Disticiiium capillaceum, Bry. Eur. 



Hab. — Twin Lakes, on wet rocks on hillsides. 



Distichium capillaceijm, var. brevifolium. — A smaller plant, with 

 shorter leaves and smaller capsule. 



Hab. — South Park, in wet, grassy ground. 



Distichium inclinatum, Swtz., B. & S. — The shorter stem, more 

 crowded leaves, and inclined oval capsule distinguish this from the preceding. 



Hab. — Twin Lakes, in similar situations. 



Ceratodon purpureus, Brid. 



Hab. — Twin Lakes, Mount Graham, and Sierra Blanca, Arizona ; very 

 common. 



Cekatodon purpureus, var. compactum. — In large, compact ceespites, 

 in a barren condition. 



Hab. — Twin Lakes, in very wet or boggy ground. 



Desmatodon latifolius, Bry. Eur. 



Hab. — South Park, along streams. 



Desmatodon Laureri, Schultz.— In close, cssspitose tufts, stems 

 branched, leaves crowded, oblong, obtuse, denticulate, with revolute, re- 

 flexed margins ; curved oval capsule, supported by a long, arcuate or cyg- 

 neous pedicel. 



