Floristik, Geographie, Systematik etc. 285 



{Oenothera leptophylla Nutt.), Oenothera longissima, O. ornata {Onogra 

 ornata A. Nels.), 0. hirsutissima [O. biemiis hirsutissima Gray), O. 

 suhuUfera [0. strigosa subiilata Rydb.), {Chylisma temässima (O. te- 

 niiissima Jones), Sphaerostigma macrophylluni {S. alxssoides macvo- 

 phyUiim Small;, Osmorrhisa intermedia {Washingtonia intermedia 

 Rydb.), Glycostna tnaxinia, Ätenia montana [Camni montanuin Blank.), 

 A. Gavrettii (C. Garrettü A. Nels.), Oreoxis MacDoiigali {Aletis Mac- 

 Dongali Coult. & Rose), Daucophyllum n. gen. {UmbelUferae) , with 

 D. te)iiiifolium {Musenitmi temiifolimn Nutt.), D . lineare {Aletes tenui- 

 folia Coult. & R.), Coriophyllus n. gen. {Umhelliferae), with C. Jonesii 

 [AidospermMn Jonesii C. & R.), C. Rosei (A. Rosei Jones) , C. purpu- 

 reiis [A. purpurewn C. & R.) and C. Betheli {A. Betheli Osterh.), 

 Pseudopteryxia n. gen. {Unibelliferae) , with P. a^iisata {Cymopteriis 

 anisatiis Gray), P. lojigiloba and P. aletifolia {Pseudocymopteriis 

 aletifolius Rydb.), Pseudoseoxis n. gen. {Umbelliferae), with P. bipin- 

 natus {Cyrnopterus bipinnatiis Wats.) and P. nivalis {C. nivalis ^Sits.), 

 Cynomarathnnn latilobnm, Cogswellia simplex [Pencedanmn simplex 

 Nutt.), and C. leptophylla {Peiicedaman triternatum leptophyllntn Hook.). 



Trelease. 



Saxton, W. T., The Classification of Conifers. (New Phyf 

 XII. p. 242-262. 1913.) 



This paper opens with a useful analysis of those characters 

 upon which a Classification of the Conifers should be based. Among 

 these, the development and structure of the pro-embrj^o and early 

 embryo are regarded as of primary importance. This introductory 

 section is foUowed by an historicai outline of the classifications hi- 

 therto published. In the latter part of the paper a new Classification 

 of the Coniferales is proposed, in which five families of approxima- 

 tely equal rank are recognized: I. Araitcariaceae^ II. Podocarpaceae, 

 III. Pinaceae, IV. Cupressaceae, and V. Taxaceae. In the case of 

 Pinaceae and Cupressaceae, a further division into sub-families is 

 suggested. These families and sub-families are defined with refe- 

 rence to gametophyte and pro-embryo characters. The paper con- 

 cludes with a section dealing with the phylogeny of the Gymno- 

 sperms, the author's views on this subject being shown graphically 

 on a Chart. A bibliograph}»^ of more than 90 memoirs, bearing on 

 the subjects discussed, is included. Agnes Arber (Cambridge). 



Shreve, F., The role ofwintertemperaturesindetermi- 

 ning the distribution of plant s. (Amer. Journ. Bot. I. 

 p. 194-202. April 1914.) 



After a discussion of the views of Willdenow, Humboldt, 

 Schouw and Merriam on the control of plant distribution by 

 the various phases of the temperature factor, Shreve details the 

 results of his observations and Instrumentation at different eleva- 

 tions in the deserts and desert mountain ranges of the soutwestern 

 United States. An attempt to determine the normal temperature 

 gradient in the Santa Catalina Mountains from 3,000 to 8,000 

 feet disclosed the very great importance of inversions of tempera- 

 ture in causing local departures from the normal gradient. These 

 gradients were determined for a number of mountain stations the 

 •gradient derived from the absolute winter minima of the Desert 

 Laboratory and of the ridge Station at 4,000 and 6,000 feet is 6,6° 



