middlesex floea. 51 



Inula, L. 



I. Helbnium, L. Elecampane. 

 Generally distributed, but not very common. July-Aug. Nat. 

 from Eu. 



Pluchea, Cass. 



P. camphorata, DC. Salt-marsh Plbabane. 

 Common along salt marshes. Aug. 



SlLPHIUM, L. 



*S. laeiniatum, L. Rosin-webd. Compass-plant. 



Concord, int. from 111. by Minot Pratt. July. 

 *S. terebinthinaceum, L. Pbaihie Dock. 



Concord, int. from 111. by Minot Pratt. July-Aug. 



Parthenium, L. 

 P. Systerophorus, L. 

 Lowell, ' ' dumps " (Dr. C. W. Swan) . Sept. Adv. from the South. 

 For description, see Wood's Bot. & Fl. 



IvA, L. 

 I. frutescens, L. 



Common along salt marshes and tidal streams. Aug. 



Ambrosia, Tourn. 



A. artemisiaefolia, L. Roman Wormwood. Ragweed. 

 Very common. A form with fertile spikes from Maiden (F. S. 

 Collins). July-Sept. 



Xanthitjm, Tourn. 



X. strumarium, L. Cocklebur. 



N. Chelmsford, wool-waste (Rev. W. P. Alcott ; specimen in herb. 



of). Aug. Adv. from Eu. 

 X. Canadense, Mill., var. echinatum, Gray. 



Maiden and Medf ord (F. S. CoUins) ; Westford, near wooUen-mill 



(Dr. C. W. Swan). More common near salt marshes. Aug. 

 X. spinosum, L. Spint Clotbttk. 



Chelmsford, Lowell, Dracut and Westford (Dr. C. W. Swan). Aug. 



Int. in wool from Trop. Am. 



Echinacea, Moench. 



*!!. purpurea, Moench. Pobplb Cone-flovtee. 

 Centralville, Lowell (Dr. C. W. Swan); Waltham List. July. 

 Adv. from the West. 



