846 



COM POSIT AE (COMPOSITE FAMILY) 



leaves silky-lanate ; corymbs 2-10 cm. broad, very convex ; involucre pubescent, 

 none of its bracts dark-margined ; rays 1-2.5 mm. long. Gravelly shores and 

 open ground, Gulf of St. Lawrence to Mich., thence westw. and southwestw.; 

 naturalised in the Eastern States. (Mex.) 



68. 



[Mich.] L. CHAMOMILE 



HK.IO. A. Cot u la. 

 Leaf and ray 



Heads many-flowered, radiate ; rays pistillate or (in no. 1) neutral. Invo- 

 lucre hemispherical, of many small imbricated dry and scarious bracts shorter 

 than the disk. Receptacle conical, usually with slender chaff at least near the 

 summit. Achenes terete or ribbed, glabrous, truncate ; pappus none or a minute 

 crown. Branching often strong-scented herbs, with pin- 

 nately dissected leaves and solitary terminal heads ; rays 

 white or yellow (rarely wanting) ; disk yellow. ('A^e/i/j, 

 the ancient Greek name of the Chainomile.) 



* Says white. 

 - Chaff of the receptacle sharp-pointed. 



1. A. COTULA L. (MAY-WEKD, DOG FENNEL.) Annual, 

 acrid, ill-scented ; leaves finely 3-pinnately dissected ; rays 

 mostly neutral ; receptacle without chaff 



near the margin; pappus none ; achenes 

 tuberculate-roughened. (Maruta DC.) 

 Common by roadsides. (Nat. from Eu.) 

 FIG. 1005. 



2. A. ARVEN8I8 L. (CORN C.) Pubes- 

 cent annual or biennial, resembling May- 



weed, but not ill-scented ; leaves less finely 1-2-pinnately 

 parted ; chaff of the receptacle lanceolate, pointed, subtending 

 all the disk-flowers and distinctly exceeding them ; achenes 

 smooth on the sides; pappus a minute border. Roadsides, 

 waste places, etc., occasional. (Adv. from Eu.) FIG. 1006. 

 Var. AGRESTIS (Wallr.) DC. Chaff of the receptacle shorter 

 than the disk-flowers. Fields, etc., becoming frequent. (Nat. 

 from Eu.) 



- - Chaff of the receptacle blunt. 



3. A. N6BILIS L. (GARDEN C.) More downy and perennial, pleasantly 

 strong-scented; sterile shoots depressed or creeping; leaves very finely dis- 

 sected ; pappus none. Occasionally spontaneous about old gardens. (Introd. 

 from Eu.) 



* * Says yellow. 



4. A. TiNCTdRiA L. (YELLOW C.) Pubescent perennial; leaves pinnately 

 divided ; heads long-peduncled, 3-4 cm. broad ; chaff of the receptacle lanceo- 

 late ; pappus a short crown. Fields and waste places, becoming frequent. 

 (Xat. from Eu.) 



A. AUREA (L.) DC., with small rayless heads has been found near St. Louis, 

 Mo. (Engelmann*). 



69. MATRICARIA [Tourn.] L. WILD CHAMOMILE 



Heads many-flowered ; rays pistillate or wanting. Bracts of the involucre 

 imbricated, with scarious margins. Receptacle conical (at least in fruit), naked. 

 Achenes 3-6-ribbed, wingless ; pappus a membranaceous crown or border, or 

 none. Smooth and branching herbs (ours annuals or biennials) with finely 

 divided leaves and single or corymbed heads. Rays white or none ; disk yellow. 

 (Named for reputed medicinal virtues.) 



1. M. INOD&RA L. Leaves bipiunately divided into fine almost filiform lobes ; 

 heads large, 3-4 cm. broad, naked-peduncled, and with many long rays ; achenes 



1006. A. arvensis. 

 Leaf and ray x 1^. 



