350 



OHIO EXPERIMENT STATION: BULLETIN 175 



for a long time. To destroy wheat-thief the plants must be uprooted very early 

 commonly the efforts to prevent it from seeding are begun only after the seeds 

 are matured. Cultivation and hand pulling are good means of destroying the 

 weed. It may be better to break up a badly infested wheat field in early spring 

 than to seed the field indefinitely with the pest. 



248 Puccoon (P) Lithospermum canescens (Michx.) Lehm. Is a softly hairy 

 plant, 1 foot or less in height, with blunt, narrow leaves and bright yellow 

 flowers. It has a deep, reddish root and grows chiefly in sandy or dry soils. 

 Destroyed by deep cutting. 



249 Comfrey (P) ^Symphytum officinale L. This 

 comfrey is a large-leaved, deep-rooted, rough plant 

 of the family, somewhat generally introduced in waste 

 places. The flowers are cream to purplish, succeeded 

 by brown nutlets. Destroyed by deep cutting. 



250 Blueweed, Viper's=bugloss (B) *Echium 

 vulgare L. Is a rough, bristly, thistle-like, intro- 

 duced weed, shown in Fig. 47. It has rather a deep 

 root and a great abundance of prickly hairs, ready 

 to become detached upon touching. Handling blue- 

 weed affords as much after pastime as a like engage- 

 ment with prickly-pear (cactus). This character 

 engages for this plant an abundance of room. Blue- 

 weed, also calk d blue-devil, is found sparingly along 

 railways and by roadsides^occasionally also in fields. 



Seeds much resembling those of wheat-thief, but 

 with broader base and angular body, 1-8 inch long. 

 The intensely bristly character of this weed calls for 



Fig. 47. Blueweed. 

 {After Vasej'.) 



destruction wherever it appears. It should be cut out with hoe or mattock in 

 early spring. 



VERVAIN FAMILY, VERBENACE^E. 



251 Narrow=leaved Vervain (P) Verbena angustifolia Michx. Is a low 

 perennial on prairie soils in northern Ohio. It has a deep root, narrow, taper- 

 ing leaves and dense spikes of purplish flowers. The seeds as in the other 

 vervains, are brown, short, slender, in clusters of four. Eradicated by the use 

 of the hoe or by cultivation. 



252 Bracted Vervain (P) Verbena bracteosa Michx. Is a similar perennial 

 plant with cut or three-cleft leaves and leaf-like bracts among the flowers. 

 Occurs in southwestern Ohio, where it may be destroyed if dealt with through- 

 out the season. 



253 Blue Vervain (P) Verbena hastata L. A tall plant, 4 to 6 feet high in 

 moist ground. It has blue flowers borne in distaff-clusters at the summit. This 

 is an unsightly weed, somewhat mildew covered as the next, and requires free 

 use of hoe or mattock to be rid of it. Seeds by fours, brown, commonly adhering 



together; singly, slender, with two straight and one curved side, 1-16 inch long. 



254 White Vervain (P. Verbena urticifolia L. White vervain is a com mom 

 weed, 3 to 5 feet high, in fields and by roadsides. It has white flowers, in 

 slender branching clusters, oval leaves which are stalked, coarsely saw-toothed 

 and pointed. There are few other plants so commonly covered with the leaf 

 mildew fungus, Erysiphe dehor ace arum DC, as is white vervain. This fungus 

 also infests phlox, ragweed and a wide range of hosts. Seeds like the last, 

 frequent in clover and grass seeds. 



The ever present mildew on this weed makes it a conspicuous and eye- 

 offending pest that may be, and certainly if appearances coun»', will be destroyed 

 by cultivation or grubbing-. 



