108 OROBANCHE AS A PARASITE IN BIHAR 



the statements of Hooker. The two species of Orobanche in Bihar are as 

 follows : — 



(1) 0. indica Ham. Flowers with two bracteoles, calyx four — rarely five- 

 toothed, divided to the base posteriorly, entire anteriorly, spikes loose flowered, 

 corolla large, blue, stem often branched. This form belongs to the section of 

 the genus named TrionycJion Wallr. and is probably identical with 0. cegyptiaca 

 Pers, {vide Beck von Mannagetta^), and very closely related to, if not identical 

 with, 0. ramosa L.^ ; this latter name is given by Massee^ as that of a species 

 which is parasitic upon tomato in England. In Bihar 0. indica is the form 

 which is the common and destructive parasite of mustard, cabbages, turnips, 

 etc. It occurs on tobacco and tomato but does not appear to be, as a general 

 rule, as serious a parasite of solanaceous crops as is 0. cernua. 



(2) 0. cernua Lceffl. Bracteoles not present, calyx divided to the base 

 posteriorly and anteriorly, lobes of the calyx bifid, spikes dense, corolla smaller 

 and paler in colour than in 0. indica^ stem usually unbranched and thicker 

 than in 0. indica, frequently showing fasciation. This species belongs to the 

 section Osp'oleon Wallr. of the genus Orobanche, and is stated by Beck von 

 Mannagetta to be identical with 0. Nicotiance Wight. Hooker, hoAvever, 

 distinguishes between these two s;^ecies and states that 0. Nicotiance differs 

 from 0. cernua in the fact that the bract in the former is as long as the corolla 

 tube and the lobes of the calyx are entire, and not divided. Prain makes no 

 mention of the species 0. Nicotiance, which, according to Hooker, is restricted to 

 the Deccan, and we have not seen any undoubted specimens although some 

 specimens of 0. cernua have closely approached to it when the lobes of the 

 calyx were only slightly divided and the bract was rather larger than usual. 



The species 0. cernua is the common parasite of solanaceous crops in 

 Bihar but does not appear to attack Cruciferce {cf. Prain), only in four 

 specimens were plants of 0. cernua found on mustard. The parasitism of this 

 species is therefore more restricted than is that of 0. indica, which, while being 

 a serious parasite on Cruciferce, does occur to a certain extent on Solanacece. 

 The life-histories of the two species appear to be identical, the " tokras " 

 appearing a few weeks after the host crop is well established and rising to flower 

 and fruit along with it. On mustard 0. indica is sometimes a good deal earlier 

 than on other crops, flowering from the beginning of December to the beginning 

 of February, while 0. cernua on tobacco is distinctly later, but there is a good 



1 Beck von Mannagetta, G. R., " Monographie der gattung Orobanche," BibUoth. Botan. 

 Heft. 19. Cassel, 1890. 



2 Hooker, p. 326 loc. cit., page 107. 



3 Massee, G., J)iseafie^ of Cidtivated Plants and Trees^ 1910. 



