326 INDEX TO AMERICAN BOTANICAL LITERATURE 
Purpus, A. LZryngium proteacfolium. Gard. Chron. III. 41: 248. 
fj. 106, 107. 20 Ap 1907. 
Purpus, J. A. Mamillaria petrophila Brandegee. Monats. Kak- 
teenk. 17: 55, 56. 15 Ap1go7.  [lllust.] 
Quehl, L. Aamillaria Knippeliana Quehl n. sp. Monats. Kakteenk. 
17: 59, 60. 15 Ap 1907. 
‘Ramaley, F_ The silva of Colorado I. Trees of the pine family in 
Colorado. Univ. Colo. Stud. 4: tog-122. F 1907. [Illust.]; II. 
The poplars, aspens and cottonwoods. Univ. Colo. Stud. 4: 187- 
197. f. 7-6. Ap 1907. 
Rand, E.L. Arceuthobium pusillum at Mt. Desert. Rhodora 9: 75, 
76. 30 Ap 1907. 
Rehder, A. Quercus prinoides Willd. var. reéfescens Var. NOV. 
Rhodora 9: 60-62. 8 Ap 1907. 
Rehder, A. Rhododendron albiflorum with double flowers. Bot. Gaz. 
43: 281, 282. 15 Ap 1907. 
Rehm, H. Ascomycetes exs. fasc. 38. Ann. Myc. 5: 78-85. 30 Mr 
Several American references, including Dermatea olivascens sp. nov. from New 
€XI1co. 
Ricker, P. L. Third supplement to new genera of fungi published 
since the year 1900, with citations and original descriptions. Jour. 
Myc. 13: 63-67. 30 Ap 1907. 
Robertson, G. R. Southern station for Botrychium simplex. Fern 
Bull. 15: 17. [Ap] 1907. 
Robinson, B. L. On the rules of botanical nomenclature adopted by 
the Vienna congress. Rhodora 9:29-55. 8 Ap 1907. 
Robinson, C. B. Contributions to a flora of Nova Scotia. I. Plants 
collected in eastern Nova Scotia in August, 1906. Bull. Pictou 
Acad. Sci. Asso. 1: 30-44. [My] 1907. 
Robinson, C.B. Jtomaea triloba 1. in the Philippines. Torrey 
7: 78-80. 15 Ap 1907. 
Rooney, B. M. Orchids of St, Johnsbury. Bull. Vt. Bot. Club2 : 29. 
Ap 1907. 
Rowlee, W. W. Localization of plants in the Finger Lake region and 
the adjacent Ontario lowlands of central New York. Torreya 
7: 69-73. 15 Ap 1907. 
Rowlee, W. W. Two new willows from the Canadian Rocky Mount- 
ains, Bull. Torrey Club 34: 157-159. 7 My 1907. 
Salix albertana and S. Maccalliana Spp. nov, 
