266 TAXONOMY, VASC. PLANTS [Bot. Absts. 



1836. Safford, W. E. Notes on the genus Dahlia with descriptions of two new species 

 from Guatemala. Jour. Washington [D. C] Acad. Sci. 9:364-373. 4 pi., fig. 1-4. 1919. — 

 The genus Dahlia should be carefully revised with the work based upon material collected in 

 Mexico and Central America, where these plants are endemic, rather than upon garden-grown 

 material as heretofore. Specimens recently collected in those regions throw new light upon 

 the origin of many of our garden forms, while illustrations made in 1575 by a Spanish explorer 

 indicate that "double-flowered" dahlias are normal and not the creation of modern horticul- 

 turalists from "single-flowered" types, as generally supposed. The new species proposed in 

 this paper are: Dahlia Popenovii and D. Maxonii. — Helen M. Gilkey. 



1837. Sargent, C. S. Notes on North American Trees. IV. Bot. Gaz. 67:208-242. 

 1919. — The present article contains critical notes and distributional data on several species 

 of trees, new combinations, and descriptions of new species, varieties, and hybrids, as follows: 

 Picea glauca var. albertina (P. canadensis var. albertina Rehder), Juniperus utahensis var. 

 megalocarpa (J. megalocarpa Sudworth), Populus tremuloides var. vancouveriana (P. van- 

 couveriana Trelease), P. arizonica (P. mexicana Sargent, not Wesmael), P. arizonica var. 

 Jonesii, P. Palmeri, P. texana, P. Fremontii var. Thornberii, P. Fremontii var. pubescens, 

 P. Fremontii var. Toumeyi, P. Parryi (P. Fremontii x trichocarpa) , Ostrya virginiana var. 

 glandulosa, Belula Eastwoodae, B. commixta (B. alaskana x glandulosa), Celtis occidentalis 

 var. canina (C. canina Raf.), C. reticulata var. vestita, C. laevigata var. Smallii, C. laevigata 

 var. texana (C. texana Scheele), C. laevigata texana f. microphylla, C. laevigata var. brachy- 

 phylla, C. laevigata var. anomala, C. laevigata var. brevipes (C. brevipes Wats.), C. pumila 

 var. georgiana (C. georgiana Small), C. pumila var. Deamii, Platanus occidentalis f. attenu- 

 ata, P. occidentalis var. glabrata (P. glabrata Fernald), Magnolia virginiana var. auslralis, M. 

 acuminata var. ludoviciana, Acer saccharum var. glaucum, (A. saccharinum var. glaiicum 

 Pax), A. saccharum var. sinuosum (A. sinuosum Rehder), A. rubrum Drummondii f. rotun- 

 data, A. Negundo var. texanum f. latifolium (A. Negundo var. latifolium Pax), A. Negundo 

 var. interior (A. interior Britton), A. Negundo var. arizonicu-m, Fraxinus americana var. 

 subcoriacea, and Castanea alnifolia var. floridana. — J. M. Greenman. 



1838. Schneider, Camillo. Notes on American willows. III. A conspectus of American 

 species and varieties of sections Reticulatae, Herbaceae, Ovalifoliae, and Glaucae. Bot. Gaz. 

 67: 27-64. 1919. — Thirty-two species are included in the present consideration of the above 

 sections. The enumeration and description of the sections and species is preceded by two keys 

 — one to the female plants and one to the male plants. The following new species, varieties, 

 and forms are characterized: Salix nivalis Hook. var. saximontana, S. rotundifolia Traut- 

 vetter forma pilosiuscula, S. arctophila Cock. var. lejocarpa (S. groenlandica var. lejocarpa 

 Lange), S. hudsonensis, and S. glauca var. acutifolia (Hook.) Schn. forma poliophylla. — 

 J. M. Greenman. 



1839. Schneider, Camillo. Notes on American willows. IV. Species and varieties of 

 section Longifoliae. Bot. Gaz. 67: 309-346. 1919. — The present paper deals with a distinctly 

 American group of willows which are assembled under the sectional name Longifoliae. Eight 

 species and eight varieties are recognized. The following are designated as new varieties or 

 new combinations: Salix exigua Nutt. var. nevadensis (S. nevadensis Watson), S. exigua var. 

 luteosericea, S. exigua var. tenerrima (S. longifolia var. tenerrima Henderson), S. melanopsis 

 Nutt. var. Bolanderiana (S. longifolia Bebb, in part, not Muhl.), S. longifolia Muhl. var. 

 Wheeleri (S. interior var. Wheeleri Rowlee). — J. M. Greenman. 



1840. Stapf, Otto. Gramineae. Flora of Tropical Africa 9 3 : 385-576. 1919.— This 

 part concludes the account of Andropogoneae and commences that of the Paniceae, ending 

 in the midst of Paspalum. Digitaria is a large genus with 49 species; Alloleropsis is based on 

 Panicum semialatum R. Br. and includes Coridochloa Nees (distinct in the key to genera); 

 Pseudechinolaena is based on Echinolaena polystachya HBK (Panicum uncinatum Raddi) 

 and distinguished from Echinolaena (E. inflexa Chase, E. hirta Desv.); Brachiaria, distin- 



