390 OROBANCHACEAE (BROOM-RAPE FAMILY) 



the ground. The crop is best used by turning under for green 

 manure, before the parasite matures seed, and clover should be 

 left out of rotation on that ground for several years. 



LOUISIANA BROOM-RAPE 



Orobdnche ludoviciana, Nutt. 

 (Myzorrhlza ludoviciana, Rydb.) 



Native. Annual. Propagates by seeds. 



Time of bloom : June to August. 



Seed-time: July to September. 



Range: Illinois to the Saskatchewan, southward to California, 



Arizona, and Texas. 

 Habitat: Parasitic on several wild plants, but has also attacked 



tobacco. 



This native Broom-rape has a wider range than either 

 of its immigrant relatives, but it is only in localities 

 suited to the growing of tobacco that it has shown 

 itself to be harmful to plants of any value. 



Stems solitary or clustered, sometimes simple but 

 usually branched, three inches to a foot in height, 

 rather stout, the stalk and the scales covered with 

 minute, glandular hairs. Scales lance-shaped, numer- 

 ous. Flowers in dense terminal spikes, each subtended 

 by one or two bracts ; calyx viscidly glandular, its five 

 lobes acute and nearly as long as the tube of the 

 corolla : the latter is purplish, slightly curved, and 

 constricted above the ovary; upper lip two-parted, 

 lower one with three lobes, pointed and entire. Cap- 



sule ovoid-oblong, two-valved, full of very fine seed. 

 FIG. 271. / F - 2?1 ) 

 Louisiana v 

 Broom -rape ,_. , 



(Orobanche Means of control 



If the ground is newly infested, the persistent hoe- 

 cutting of the parasites from the roots of their hosts 

 before any seed can be perfected, piling and burning them with 

 oil-soaked straw or other litter, will be well invested labor. After 

 the crop is harvested and cured, the stalks should be burned. 

 Plant no more tobacco on the infested ground for several seasons. 



