Observations on Conopholis Americana. 



(WITH PLATES l-Vl.) 



By Lucy L. W. Wilson, Ph. D. 



Head of the Biological Department, Philadelphia Normal School. 

 [Thesis presented to the University of Pennsylvania 1 



I. History axd Literature. 



IT is now nearly twenty -two hundred years since Theophrastus 

 Eresius (died 286 B. C.) appropriately bestowed upon a 

 plant, which still bears the same name, the title of Oroban- 

 cht\ literally peachokcr. This name in extended form was 

 afterwards applied to the whole order, which now includes 

 some hundred and fifty species. Yet, in spite of the lapse in 

 time, the family itself has been comparatively little studied. 

 This seems doubly strange when one recalls their peculiar 

 habits of growth, habits so well known and so characteristic 

 that it was in describing them that Micheli in 1720 {'' De 

 Orobanchc") first used the now common word parasite. 



The literature cited in Engler-Prantl's " Pflanzenfamilien " 

 by Giinther Beck von Mannagetta in 1891 is given below.* 



To this should be added Chatin's "Anatomic Comparee des 

 Vegetaux. Plantes Parasites," (Paris, 1892). 



The absence of literature is especially noticeable in the case 

 of the species which is the subject of this paper. With the 

 exception of the mention of its gross specific characters in the 

 various Floras and Prodromuses, most of which have been 

 cited above, from the time of Linneus to the present, nothing 



* Wallroth, Orobanches Generis (1825); Vaucher, Monographic des Orobanches 

 (1827); G. Beck, Monographie der Gattung Orobanche (1890), Bibl. Bot. Heft 

 19; Baillon, Hist, des Plantes (1891); Endlicher, Gen. Plant (1836-1840); 

 Reuter in D. C. Prod. XI (1847); Hooker and Bentham's Gen. Plant. II (1873); 

 Hooker, Flora Brit. Ind. (1885); Gray, Syn. Flora N. Am., II (1886); L. Koch, 

 Die Entwicklungsgeschichte der Orobanchen (Heidelberg, 1887); Hovelacqii'2, 

 Rech. sur I'appareil veget. des Bign. Rhin. Orob. (Paris, 1888). 



