— lOO — 



ing to yellowish green or reddish brown: stems prostrate, defoliate or with a 

 few rudimentary leaves, sparingly branched ; branches filiform, diffusely 

 spreading, 2-5 cm. long: branchlets flagellate, brittle, broken M^hen dry; 

 larger branch-leaves narrowly ovate-lanceolate, long-acuminate, erect, not 

 plicate, entire or serrrulate above, 0.15-0.2 mm. wide, 0.3-0.5 mm. long; 

 costa thin, commonly marked by 3 or 4 rows of enlarged cells, disappearing 

 below the middle; leaf- cells smooth, clear, not uniform; median cells oval- 

 rhombic to linear-rhomboidal, 2-4 times as long as wide; alar quadrate, in 3 

 or 4 rows; leaves of branchlets similar, smaller, sometimes rudimentary; 

 sterile. 



Type of variety collected by Mr. L. F. Anderson on rocks near Lahoon, 

 Idaho. Drummond's Musci Americana 219, in part; Brandegee's Mosses of 

 Southern Colorado 38. 



This delicate little moss appears to have been a standing puzzle for sev- 

 eral years. It was found in some of the sets of Drummond's Musci Americana 

 No. 219, but not in all, and was distributed as Hyp7iH7}i catenulatum. Some of 

 the other sets of this number, but not all, contained Heterocladiuin heteroP' 

 terioides filesceiis, a moss it closely resembles, but which differs in being 

 papillose. Some years ago Mr. Gepp sent me from the Natural History 

 Museum in London a portion of one set of Drummond's 219 bearing the 

 name of Hypmim graveolens Wils. It therefore appears that so good an 

 authority as Wilson had discovered that the moss in question was Xio\. Leskea 

 cateimlata (Brid. ). Subsequently Mrs. Britton gave me some specimens of 

 Brandegee's No. 38, which I named Heterocladiuin heteroptermn fallax 

 Milde? A careful study of Drummond's 219 and Brandegee's .38 made it 

 obvious that we had to deal with an attenuated form of some species which 

 under more favorable conditions grew better developed. 



(6) Leskea tectorum flagellifera Best. 



In somewhat dense compact tufts, pale green to yellowish-brown: stems 

 prostrate, pinnately branched: branches filiform with numerous flagellate 

 deciduous branchlets; stems defoliate, rarely with rudimentary leaves; 

 branch-leaves as in type but usually much smaller; leaf-cells smooth, clear, 

 oval-rhombic: leaves of branchlets very small, 0.05-0.1 mm. wnde, o 1-0.2 

 mm. long. Differs from L. IVilliainsi filameiitosa by its entire leaves and 

 larger leaf-cells. Type of variety collected by Mr. R. S. Williams at Colum- 

 bia Falls, Montana, Sept. 5, 1895; found also by Professor Holzinger in 

 Minnesota. It usually grows on rocks and rotten wood. 



The North American Heteroleskeae differ from the European by being 

 usually more markedly proliferous. The somewhat dense tuftsof vox. flagelli- 

 fera are mostly flagellate branchlets which when dry readily separate from 

 their attachments. By soaking these tufts and dissecting out the stems and 

 branches leaves m.ay usually be found sufficiently developed to make possi- 

 ble the identification of the plants. 



(7) Leskea gracilescens (Hedw) Best. 



L. gracilescens is quite common and widely distributed, ranging through 

 the Eastern, Middle, Northern and Western States, rare in Canada and in the 

 Southern States and absent west of the Rocky Mountains. It differs from 

 the closely related L. polycarpa by its smaller straight leaves which are 

 shorter and comparatively broader, usually gradually acute and blunt 



