248 COMPOSITE. (COMPOSITE FAMILY.) 



perennial herbs, viscid-hairy, exhaling a heavy odor. Leaves large and thin, 

 opposite, or the uppermost alternate, lobed, and with dilated appendages like 

 stipules at the base. Heads in panicled corymbs. Flowers light yellow ; in 

 summer and autumn. (Dedicated to the Muse, Polyhymnia, for no obvious 

 reason, as the plants are coarse and inelegant.) 



1. P. Canad6nsis, L. Clammy-hairy; lower leaves deeply pinnatifid, the 

 uppermost triangular-ovate and 3-5-lobed or angled, petioled; heads small; 

 rays few, obovate or wedge-form, shorter than the involucre, whitish-yellow. Moist 

 shaded ravines, W. New York (and Weehawken, New Jersey, Dr. Allen) to 

 Pcnn., Wisconsin, and southward along the mountains. Var. DISCOIDEA has 

 the corolla of the ray-flowers reduced to a mere ring around the base of the style. 

 Mt. Carroll, Illinois, Henry Shimer. 



2. P. Uvedalia, L. Boughish-hairy, stout (4 -10 high); leaves broadly 

 ovate, angled and toothed, nearly sessile ; the lower palmately lobed, abruptly 

 narrowed into a winged petiole; outer involucral scales very large; rays 10-15, 

 linear-ob/ong, much longer than the inner scales of the involucre, yellow. Rich soil, 

 W. New York and New Jersey to Illinois and southward. 



26. CHRYSOGONUM, L. CHRYSOGONUM. 



Heads many-flowered, radiate ; the rays about 5, pistillate and fertile ; the 

 disk-flowers perfect but sterile. Involucre of about 5 exterior leaf-like oblong 

 scales, which exceed the disk, and as many interior shorter and chaff-like con- 

 cave scales. Receptacle flat, with a linear chaff to each disk-flower. Achenia 

 all in the ray, obovate, obcompressed, 4-angled, each one partly enclosed by the 

 short scale of the involucre behind it ; those of the disk-flowers abortive. Pap- 

 pus a small chaffy crown, 2 - 3-toothed, and split down the inner side. A low 

 (2'-6' high), hairy, perennial herb, nearly stemless when it begins to flower, 

 the flowerless shoots forming runners. Leaves opposite, ovate or spatulate, cre- 

 nate, long-petioled. Heads single, long-peduncled. Flowers yellow. (Name 

 composed of xpvaos, golden, and yow, knee.) 



1. C. Virginianum, L. Dry soil, from Pennsylvania (Mercersburg, 

 Prof. Porter) and Illinois southward. May - Aug. Rays ' long. 



27. SlliPHIUM, L. ROSIN-PLANT. 



Heads many-flowered, radiate ; the rays numerous, pistillate and fertile, their 

 broad flat ovaries imbricated in 2 or 3 rows ; the disk-flowers apparently perfect, 

 but with undivided style, and sterile. Scales of the broad and flattish involu- 

 cre imbricated in several rows, broad and with loose leaf-like summits, except 

 the innermost, which are small and resemble the linear chaff of the flat recep- 

 tacle. Achenia broad and flat, obcompressed, surrounded by a wing which is 

 notched at the top, destitute of pappus, or with 2 teeth confluent with the 

 winged margin : achenia of the disk sterile and stalk-like. Coarse and tall 

 rough perennial herbs, with a copious resinous juice, and large corymbose- 

 panicled yellow-flowered heads. (2i'X$ioi>, the ancient name of a plant which 

 produced some gum-resin, perhaps assafoetida, was transferred by Linnaeus to 

 this American genus.) 



