COMPOSITE. (COMPOSITE FAMILY.) 225 



1. TXI, latifolia, Pursb. Stems leafy; leaves ovate-lanceolate, pointed, 

 sessile. — Dry soil, Virginia and southward. (M. lanceolata and M. an- 

 GUSTIFOlia may occur in S. Virginia.) 



50. GALINSOGA, Ruiz & Pav. Galinsoga. 



Heads several-flowered, radiate ; the 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 (l°high); 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. MABIJTA, Cass. Mat-weed. 



Heads many-flowered, radiate ; the rays neutral. 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. M. Cotula, DC. (Common Mat-weed.) Scales of the involucre 

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



52. AN THE MIS, 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 

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

 heads. Rays white, the disk yellow. {'Avdefiis, the ancient name, given in 

 allusion to the profusion of the flowers.) 



1. A. arvensis, L. (Corn 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. (§) — Piclds, N. Eng- 

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

 (Adv. from Eu.) 



A. nobilis, 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. 

 Receptacle 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 Achilles.) 



