990 



COMPOSITAE 



Matricaria 



50 



Map 2170 



Achillea Millefolium L 



Map 2171 

 Matricaria matricanoides (Less! Porter 



by creeping rootstocks and is difficult to exterminate. It is found every- 

 where in dry soil except in deep woodland and cultivated fields. 



Eurasian, and by most authors regarded also as a native. Now found 

 throughout the U. S. 



9339. MATRICARIA [Tourn.] L. 



1. Matricaria matricarioides (Less.) Porter. (Matricaria suaveolens 

 (Pursh) Buchenau.) Rayless Camomile. Map 2171. This species has 

 been reported from only three counties yet I believe it may be found 

 throughout the state. The decumbent habit of the plant and its rayless 

 heads have, I believe, led collectors to pass it by, thinking that such speci- 

 mens were trampled down or non-flowering specimens of Anthemis Cotula. 

 I know that I so regarded the species for many years until I discovered my 

 error. All of my specimens are from barnyards except one which is from 

 a roadside. 



Adventive from the Pacific coast. 



9341. CHRYSANTHEMUM [Tourn] L. 



Heads few or solitary, mostly 3-5 cm wide; rays white, spreading; leaves glabrous, 



pinnately incised. 



Basal leaves spatulate-obovate, on long slender petioles, the blades crenate-dentate; 



middle and upper stem leaves oblong or oblanceolate, coarsely and regularly 



crenate or dentate above, with larger, spreading teeth at base. (See excluded 



species no. 675, p. 1102) C. Leucanthemum. 



Basal leaves pinnatifid, subpinnatifid or coarsely and irregularly toothed; middle 

 and upper stem leaves narrowly oblong or oblanceolate, conspicuously subpin- 

 natifid at base 1. C. Leucanthemum var. pinnatifidum. 



Heads numerous, less than 1.5 cm wide; leaves puberulent, crenate-serrate or pin- 

 nately parted. 

 Leaves oblong, crenate-serrate; heads rayless, 6-8 mm wide; inner bracts with color- 

 less, scarious, erose tips 2. C. Balsamita var. tanacetoides. 



Leaves pinnately parted; heads mostly 12-20 mm wide, inner bracts more or less 



scarious-tipped and brownish. (See excluded species no. 676, p. 1102) 



C. Parthenium. 



