120 FLORA OF MOUNT DESERT. 



ERECHTITES, Kaf. Fireweed. 

 E. hieracifolia (L.), Eaf. 



Wood clearings, especially in recently burned ground; 

 common. 



ARCTIUM, L. Burdock. 

 A. Lappa, L. 



Common in waste places, especially about old dwellings. 

 Naturalized from Europe. 



CNICUS, L. Thistle. 



C. LANCEOLATUS (L.), Hoffm. COMMON Thistle. 



Pastures, fields and roadsides; common. Naturalized from 

 Europe. 



C. ARVENSIS (L.), Hoffm. Canada Thistle. 



Pastures, fields, and roadsides; too common. Naturalized 

 from Europe. 



Forma albiflorus. 



Flowers pure white. Southwest Harbor (Rand) ; — Seal Har- 

 bor (Wm. C. Lane). 



CENTAUREA, L. Star Thistle. 



C. Cyanus, L. Bluebottle. Bachelor's BuTTOff. 



Occasionally escaped from cultivation to roadsides and waste 

 places, Southwest Harbor, etc. (Rand, Annie S. Downs). 



ARNOSERIS, Gsertn. Lamb's Succory. 



A small, annual, scapigerous herb; juice milky; leaves all 

 radical; heads few, small; peduncles clavate, fistular; involu- 

 cral bracts in one series, many, after flowering arching over the 

 fruit ; receptacle flat, naked, pitted ; corollas all ligulate, 

 yellow; anther cells not tailed; upper part of style and its 

 short obtuse arms hairy ; fruit obpyramidal, furrowed and 

 ribbed, not beaked, crowned by a coriaceous angular ring. 



