CONTRIBUTIONS TO WESTERN BOTANY NO. 15 43 



i 



■sors, and his monumental botany of the 40th paralle has never been 

 equaled for quality of work since, though it has been followed as a 

 guide by men too selfish to give credit where it belonged. He was a 

 pioneen Had to solve relationships entirely unknown to others. A study 

 of the genera of Cruci ferae to determine just how much worth is in the 

 work of Payson has revealed to me certain things which lack o: 



knowing 



ijsym 



brium are simply hodgCnpodges. It is out of the question to consider 

 E. cheiranthoides as congreneric with the rest referred to it. Therefore 

 I incline to keep up Cheiranthus. Sisymbrium is more muddled, and 

 Payson only contributes more fog- In hi-s treatment of Thelypodium lie 

 makes a great ado about the markings of the septum as distinctive, but 

 the sections here shown reveal his fallacies. But he fails to consider 

 tlie septum of the other genera. Climatic influences seem to determine 

 the peculiar markings largely. At the north the vein's orl cell walls ?n' 

 nearly always crimped, at the south nearly always straight or nearly %\ 

 Individual species vary much in this regard. It certainly is amusing to 

 see Thelypodium Cooperi put in Caulanthus along with Sisymbrium re 

 flexum, and see Streptanthus longirostris which seems almost congeneric 

 with it (Cooiperi) put in Streptanthella. Mr. Payson does not seera 

 to regard certain morpholc^ical characters a5 of any particular valu^ 

 such as the peculiarly stout and rigid floral peduncle, so characteristic 

 of S. altissimum, and reflexum. Nor does he seem to know how 

 greatly the two species differ in the meshes of the septum. S. ahissinium U 

 properly called the type of the genus Sis}Tnbrium. It has false pa^tition^ 

 between the seed's, remarkably developed walls to the pods, as well ^-^ 

 woody and very rigid reflexed pedicels, quite different from S. canesccn^ 

 group, while the S. reflexum group is intermediate, then all these are 

 annuals. Watson sidesteps these cOTnplications by saying that the Cruci- 

 ferae form natural groups, his use of the term natural being intend^-! 

 to mean evolutionarily natural, since he was a believer apparently ii^ 



Speaking of the idea 



hpment 



pe 



niaU, an idea which I certainlv combat, the great genus Astragalus i^ 



conspicuous exam 

 highly develdped species 



the 

 seen 



by reference to my monograph. The fact that this is characteristic of 

 Astragalus does not prove that it is a universal rule of course in all 

 genera, but presents presumptive evidence therefore. 



It is evident to western botanists that the genera Thel}^:xx^iun^ 

 Stanleya, Streptanthus, and Caulanthus are developments of very recent 

 times, from older genera of the Sis}7nbrium-Arabis type, all of w^hich 

 are stipeless. This therefore leads to the assumption that stipes are not 

 primitive a's Payson has assumed, but the last word in Specialization. It 

 13 goings far too long a distance into the unknown past to resurrect the 

 axial habit and call the stipe a long lost pedicel, as Payson does. Geo- 

 logical history shows only too well that certain types of forms early be- 

 came fixed and were built upon in the later ,^^e^s ^ species without 



