826 coMPOSiTAB (composite family) 



* * * Stem square ; leaves opposite, connate, 1.5-3.5 dm. in length. 



0. S. perfoliatum L. (Cup Plant.) Stem stout, often branched abovBi 

 1-2.5 m. high, leafy ; leaves ovate, coarsely toothed, the upper united by their 

 bases and forming a cup-shaped disk, the lower abruptly narrowed into winged 

 petioles which are connate by their bases ; heads corymbose ; bracts ovate; 

 aohenes winged and variously notched. — Rich soil, Ont. to S. Dak., and southw., 

 common ; also escaped from gardens eastw. July-Sept. 



36. BERLAWDIERA DC. 



With the characters of Silphinm, but the 5-12 fertile ray-fiowers in a single 

 series. Involucral bracts in about 3 series, thinner ; the inner dilated, obovate, 

 exceeding the disk ; the outer smaller and more foliaceous. . Achenes without 

 jjappus, obovate, neither winged nor notched at the apex, deciduous with the 

 subtending bract and 2-3 scales of the chaff. — Alternate-leaved perennials 

 of the Southern and Southwestern States ; head pedunculate. (Named for J. L. 

 Berlandier, a Swiss botanist who collected in Texas and Mexico.) 



1. B. texjlna DC. Ilirsute-tomentose or villous, 6-9 dm. high, very leafy; 

 leaves crenate, the radical oblong, petiolate, the cauline oblong-cordate to sub- 

 cordate-lanceolate, the upper closely sessile ; heads somewhat cymose, 3-4 cm. 

 broad. — Mo. and Kan., southw. and south westw. 



37. chrys6gonum l. 



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

 flowers perfect but sterile. Involucre of about 5 outer leaf-like oblong bracts 

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

 scales. Receptacle flat, with a linear scale to each disk-flower. Achene obovate, 

 obcompressed, 4-angled, partly inclosed by the short subtending involucral bract ; 

 pappus a small chaffy 2-3-toothed crown. — A hairy perennial herb, with oppo- 

 site long-petioled leaves, and solitary long-pednncled heads of yellow flowers, 

 nearly stemless when it begins to flower, the flowerless shoots forming runners. 

 'The Greek name of some plant, composed of xpi'o'is, golden, and 76 w, knee.) 



1. C. virginianum L. Usually low (0.5-3.5 dm. high); leaves ovate, mostly 

 obtuse, crenate, rarely somewhat cordate, or the radical obovate with cuneate 

 base; rays 1-1.5 cm. long. — Dry soil, s. Pa. to Fla. May-Aug. Var. dbntItdm 

 Gray. Leaves deltoid-ovate, acute, coarsely dentate-serrate; involucral scales 

 more acute. — High Island at the Falls of the Potomac. 



38. PARTHENIUM L. 



Heads many-flowered, inconspicuously radiate ; ray-flowers 5, with very short 

 and broad obcordate ligules not projecting beyond the woolly disk, pistillate and 

 fertile ; disk-flowers staminate, with imperfect styles, sterile. Involucre hemi- 

 spherical, of 2 ranks of short ovate or roundish bracts. Receptacle conical, 

 chaffy. Achenes only in the ray, surrounded by a slender callous margin, 

 crowned with the persistent ray-corolla. — Leaves alternate. Heads small, 

 corymbed ; the flowers whitish. (An ancient name of some plant, from vapBivo^, 

 virgin.") 



* Upper leaves sessile, but not auricled. 



1. P. integrifblium L. Scabrous perennial, 1 m. or less high, from a thick- 

 ened rootstock ; the stems glabrous below, minutely puberulent above; leaves 

 oblong or ovate, crenate-toothed, or the lower (0.5-1.5 dm. long) cut-lobed be- 

 low the middle ; hoads many in a very dense flat corymb. — llry soil, Md. to 

 Minn., and southw. June-Aug. 



2. P. rSpens Eggert. Similar but lower, /row a slender stoloniferous root- 

 stock; stems and leaves pilose-hispid ; heads few, rather larger. — Barrens, Mo- 

 and Kan. to Tex May, June, 



