694 Rydberg : Rocky Mountain flora 



Wor 



The typical Orohanche has the calyx characteristic of, for instance, 

 Castilleja in Scrophulariaceae, /. e., the calyx is deeply cleft in 

 front and behind, with the lateral divisions entire or 2-cleft. None 

 of our native American plants has this structure. They have all 

 (except those included in Boschniakia by Gray) an almost equally 

 5 -toothed calyx. There is a group of Old 

 Orohanche purpurea 2x\A 0. ramosa are introduced into this country, 

 which have a 4-toothed or only occasionally 5-toothed calyx, but 

 in that case the upper tooth is much smaller. In Gray's New 

 Manual the former is described as having a '^5-lobed" calyx. 

 This is only occasionally the case. These species constitute the 

 genus Kopsia Dum. or PJielipaea Nees (not Desf.). The writer 

 thinks that the five sections of Beck's monograph should be re- 

 garded as genera. MyzorrJiiza Philippi is the only available name 

 iox ApJiyllon § Nothaphylloti Gray, This genus differs from TJialesia 

 in habit and in the arrangement of the placentae, from Orobanche in 

 the regularly 5-toothed instead of 2- cleft calyx, and from both in 

 the presence of bractlets. The type of the genus is 



My 



1857 



Orobanche chilensis G. Beck, Bibl. Bot, 4 : 82. 1890. 



This is closely related to our most common North American 

 species : 



Myzorrhiza ludoviciana (Nutt.) Rydb.; Small, Fl. SE. U. S. 



1093. 1903 



Orobanche ludoviciana Nutt. Gen. 2 : 58. 18 18. 

 Phelipaea ludoviciana WdX^. Rep. 3: 461. 1844. 

 Aphyllon ludoviciamim A. Gray, Bot. Calif. 1:58 

 } Aphyllon arenoswn Suksd Allg. Bot. Zeits. 12 : 



. 1876. 



27. 1906. 



given for the two first are correct ; there are three scales under the flower, one bract 

 and two lateral bractlets ; Orobanche vtinor has one bract and no bractlets, while O, 

 ludoviciana has i or 2 bractlets under the flower. It has exactly the same arrangement 

 as O, pu7'purea and O. ramosa^ except that one of the bractlets is sonaetimes lacking 

 and the bract is usually some distance below the calyx. Orobanche tinijlora and O. 

 fascicidata are not without bracts. They are without bractlets, but the bract is found at 

 the base of the longer pedicel. They are like 0. minor (a typical Orobanche^ in hav- 

 ing no bractlets, but differ in the 5-toothed instead of 2-cleft calyx. 0, ludoviciana 

 has bractlets and should have been associated with the two first species, if the presence 

 or absence of bractlets was taken as the dividing character. In all the species the 

 bracts are present although situated at diflerent distances from the calyx, depending 

 upon the length of the pedicels. 



