Floristik und Systematik der Phanerogamen. 25 



each is a historical survej' and a criticai digest, with the author's views 

 on each topic. Association involves tlie idea of the relation of plants to 

 the soil, as well as of plants to each other, and is synononious with 

 Vegetation, when these two relations are represented. Invasion may be 

 subdivided into migration and ccesis, or the establishment of migrated 

 iornis. Linder the hcad of invasion^ barriers^ endemism and polygenesis 

 are also considered. Succession is represented by primary and secon- 

 dary succession, and the kinds, causes, reactions and laws of successions 

 lind treatment. The concepts of zonation and aiternation, the static 

 phenomena of Vegetation, are developed in contrast to those of invasion 

 and succession. which represent the dynamic forces. By aiternation is 

 conceived the response of Vegetation to the heterogeniety of the earth's 

 surface, and is developed and defined by the author, more fully than 

 heretofore. H. M. Richards (New York). 



COCKERELL, T. D. A.. The North American s p e c i e s o f 



Hymenoxys. (Bulletin of the Torrev Botanica! Club. XXX!. 



p. 4ol-,o09. pl. 20—23. September 1904.) 



An analysis recognizing four subgenera: Picradenia, Picradenidia, 

 Phileozera and Picradeniclla and inciuding the foilowing new names : 

 PlateUctna Palmeri (ActineUa Palineri Gray), Hymenoxys Richardsoni 

 (Picradenia Ricliardsoni Hooker), H. Richardsoni pnmila (Picradenia 

 puniila Greene), H. Richardsoni Macouni, H. Richardsoni ligiüaeflora 

 (Hymenopappus ligiilaeflorns Nelson), H. Richardsoni macrantha (Picra- 

 denia macrantiia Nelson), H. Ricliardsoni Nelson, H. Richardsoni Uta- 

 hensis, H. Lemnioni (Picradenia Lemmoni Greene), H. Lemnwni Greenei 

 (Picradenia biennis Greene, in part), H. subiniegra, H. helenioides (Pi- 

 cradenia helenioides Rydberg), H. canescens (ActineUa Ricliardsoni ca- 

 nescens Eaton), fi. canescens biennis (ActineUa biennis Gray, H. ca- 

 nescens nevadensis, ti. floribunda (ActineUa Richardsonii flori- 

 bunda Gray), H floribunda utilis (Picradenia floribunda iitilis 

 Cockerell), H. floribunda arizonica, H. floribunda intermedia, H. Earlei 

 (Picradenia Earlei Cockerell), H. Metcalfei, H. Vaseyi (ActineUa Vaseyi 

 Gray), H. Cooperi (ActineUa Cooperi Gray), //. Cooperi Grayi, H. Coo- 

 peri argyrea, H. Rnsbyi( ActineUa Rusbyi Gray), H. olivacea, fi. latissima, 

 H. te.xana (ActineUa te.xana Coulter and Rose), H. chrysanihemoides 

 e.xcurrens, H chrysanihemoides juxta, H. chrysanthemoides Osterhouti 

 (Picradenia odorcUa Osterhouti Cockerell), H. chrysanihemoides Mearnsi, 

 H. chrysanthemoides niultiflora (Phileozera multiflora Buckley) "and H. 

 Düvidsonii (Picradenia Davidsonii Greene). Trelease. 



Engler. A.. Beiträs^e zur Flora von Afrika. XXVI. 



^Engler's Jahrb. XXXIV. 1904. p. 256—376.) 



Enthält: 



Müller, 0., BaciUariacecn aus dem Nyassalande und einigen 

 benachbarten Gebieten. IL 



Engler, A., Burseraceae africanae. III. 

 Engler, A., Violaceae africanae. II. 

 Schumann, K., Tiliaceae africanae. II. 

 Schumann, K., Sterculiaceae africanae. II. 

 Schumann, K., Apocynaceae africanae. II. 

 Schumann, K., Asclcpiadaceae africanae. 11. 

 Schumann, K., Rubiaceae africanae. iL 

 Oilg, E., Cncurbitaceae africanae. IL 

 Pax, F., Euphorbiaceae africanae. VII. 



Neue Gattungen: Stephanostema K. Schum. (p. 325j — Apocynaceae; 

 Dolichonietra K. Schum. (p. 331) — Rubiaceae. 



Neue Arten: Conimiphora subsessilifolia Engl., C. Ellenbeckii Eng!., 

 C Hndensis Engl. (303), C. flaviflora Engl. (304)^ C. arussensis Engl. 



