COMPOSITE. (COMPOSITE FAMILY.) 225 



1. M. latifolia, Pursh. Stems leafy; leaves ovate-lanceolate, pointed, 

 sessile. Dry soil, Virginia and southward. (M. LANCEOLATA and M. AN- 

 GUSTIFOLIA may occur in S. Virginia.) 



5O. C* A L, I N S 6 G A , Ruiz & Fav. GALINSOGA. 



Heads several-flowered, radiate; tho rays 4-5, small, roundish, pistillate. 

 Involucre of 4 or 5 ovate thin scales. Receptacle conical, with narrow chaff 

 among the flowers. Achenia angled. Pappus of small oblong cut-fringed 

 chaffy scales (sometimes wanting). Annual herbs, with opposite triple-nerved 

 thin leaves, and small heads : disk-flowers yellow : rays whitish. (Named for 

 Galinsoga, a Spanish botanist.) 



1. G. PARVIFL6RA, Cav. Smoothish (lhigh); leaves ovate, acute, some- 

 what toothed ; scales of the pappus 8-16. Waste places ; Cambridge, Mass., 

 New York, and Philadelphia. (Adv. from S. Amer.) 



51. MA RUT A, Cass. MAY-WEED. 



Heads many-flowered, radiate ; the rays neut ' Involucre of many small 

 somewhat imbricated scales, shorter than the disk. Receptacle conical, bearing 

 slender chaff, at least near the summit. Achenia obovoid, ribbed, smooth. 

 Pappus none. Annual acrid herbs, with a strong odor, finely thrice-pinnately 

 divided leaves, and single heads terminating the branches. Rays white, soon 

 reflexed; the disk yellow. (Derivation unknown.) 



1. ]JI. COTTJLA, DC. (COMMON MAY-WEED.) Scales of the involucre 

 with whitish margins. Road-sides ; very common. (Nat. from Eu.) 



52. ANTHEMIS, L. CHAMOMILE. 



Heads and flowers as in Maruta, but the rays pistillate. Achenia terete, stri- 

 ate or smooth. Pappus none, or a minute crown. Herbs with aromatic or 

 Btrong odor, 1 - 2-pinnately divided leaves, the branches terminated by single 

 heads. Rays white, the disk yellow. (*A.v6fp.is, the ancient name, given in 

 allusion to the profusion of the flowers.) 



1. A. ARVENSIS, L. (CORX CHAMOMILE.) Pubescent ; leaflets or divisions 

 linear-lanceolate, toothed, very acute ; branchlets leafless at the summit ; chaff 

 lanceolate, pointed, membranaceous ; achenia crowned with a very short some- 

 what toothed margin ; those of the ray sometimes sterile. Fields, N. Eng- 

 land and New York, sparingly introduced. Much resembles the May-weed. 

 (Adv. from Eu.) 



A. N6BILI8, L., the officinal CHAMOMILE, is said to be somewhat natural- 

 ized in Delaware. 



53. ACHILLEA, L. YARROW. 



Heads many-flowered, radiate ; the rays few, fertile. Involucre imbricated. 

 Beceptacle chaffy, flattish. Achenia oblong, flattened, margined. Pappus 

 none. Perennial herbs, with small corymbose heads. (So named because its 

 virtues are said to have been discovered by Achittes.) 



