CARDUACEAE 1247 
blades, the upper with oblong-lanceolate or ovate sessile blades : heads few, showy : invo- 
lucres campanulate, 1-2 cm. high ; bracts linear-lanceolate or lanceolate to ovate or oblong, 
ciliate and with afew stalked glands on the margins, the outer acute, the inner obtuse : ray- 
flowers 4-5 ; ligules bright yellow, 1.5 cm. long : achenes obovate, 6-7 mm. long, with the 
wing prolonged in 2 horn-like teeth. 
In open woods and sandy soil, Texas. 
75. ENGELMANNIA T. & G. 
Perennial caulescent herbs, with pubescent foliage. Leaves alternate : blades pinnatifid, 
the segments often toothed. Heads radiate, peduncled. Involucres hemispheric or cam- 
panulate : bracts in 2-3 series, the outer narrow, the inner broader, and subtending the 
ray-flowers. Receptacle flat, chaffy. Ray-flowers 8-10, pistillate, fruit-producing. Disk- 
flowers several, perfect, not fruit-producing, partly embraced by the bractlets. Anthers 
minutely 2-toothed at the base. Achenes flat, broadened upward, 1-ribbed on each face. 
Pappus an irregular persistent crown. 
1. Engelmannia pinnatifida T. & G. Roots stout. Stems 3-7 dm. tall, hirsute or 
hispid, more or less widely branched above: leaf-blades 3-15 cm. long, deeply pinnatifid, 
the lower ones long-petioled, the upper sessile: heads showy : involucres 7-8 mm. high ; 
bracts various, the outer linear, those of the second series with suborbicular bodies and 
linear tips, those of the inner series oval or obovate, short-tipped, all ciliate, obtuse : ray- 
nr 8-10 ; ligules golden yellow, about 1 cm. long : achenes oblong-ovate, 4 mm. long, 
ciliate. 
On prairies or open hillsides, Kansas to Arkansas, Louisiana and Arizona. Spring. 
76. PARTHENIUM L. 
Perennial or sometimes annua) caulescent herbs, or shrubs. Leaves alternate: blades 
toothed, pinnatifid or dissected. Heads radiate, but not conspicuous. Involucres hemis- 
pheric, campanulate or flat, peduncled : bracts in 2-3 series, appressed, obtuse. Recep- 
tacle convex or conic, chaffy. Ray-flowers usually 5, pistillate, fruit-producing: ligules 
broad but very short, white or whitish. Disk-flowers perfect, not fruit-producing, embraced 
by the bractlets. Anthers entire at the base.  Achenes flattened, margined, keeled on the 
inner face, tipped with the persistent ray-flower. Pappus of 2-3 scales or awns. 
Leaf-blades 1-2-pinnatifid : heads not firm at maturity. 
Leaf-blades pinnately parted, the segments pinnatifid or toothed. 1. P. Hysterophorus. 
Leaf-blades lyrately pinnatifid. i 2. P. lyratum. | 
Leaf-blades merely toothed: heads very firm at maturity. 3. P. integrifolium. 
1. Parthenium Hysteróphorus L. Annual, strigose or sometimes slightly hirsute. 
Stems 3-7 dm. tall, more or less diffusely branched : leaf-blades oblong to ovate in outline, 
1-2-pinnately parted, the segments lanceolate to linear, pinnatifid or toothed: heads nu- 
merous: involucres saucer-like, 4-5 mm. broad; bracts concave, the outer rhombic or 
elliptic-rhombic, the inner broader, cuneate at the base: ray-flowers few ; ligules whitish, 
reniform, less than 1 mm. broad: disk-corollas 1-1.5 mm. long: achenes obovate, 1-1.5 
mm. long. 
In sandy soil and waste places, Florida and Alabama to Texas. Also in tropical America. 
2., Parthenium lyratum A. Gray. Perennial, canescent or somewhat hirsute. Stems 
1-4 dm. tall, solitary or tufted, branching above: leaf-blades ovate, suborbicular or ob- 
ovate in outline, palmately lobed or lyrately pinnatifid, 1-3 cm. long, the lower ones long- 
petioled : heads numerous : involucres flattish, 5-6 mm. broad; bracts various, the outer 
oval, obtuse, the inner broader than high, notched at the apex, truncate at the base: ray- 
flowers few ; ligules cup-like, about 1 mm. long: disk-corollas 2-2.5 mm. long: achenes 
obovate or rhombic-obovate, 3 mm. long, with 2 ovate teeth at the top. 
In dry soil, Texas. Spring to fall. 
" 3. Parthenium integrifdlium L. Perennial, scabrous-pubescent. Stem 4-12 dm. 
tall, sometimes clustered, corymbose above : leaf-blades 1-3 dm. long, various, those of the 
asal and lower stem-leaves oblong or lanceolate, long-petioled ; the upper stem-leaves 
elliptie, oblong ovate or oval, sessile, all acute, singly to triply dentate or crenate-dentate : 
eads several or numerous, often crowded : involucres campanulate, becoming globular, 
4-6 mm. high ; bracts oblong, ovate or suborbicular, obtuse : ray-flowers few ; ligules white 
or cream-colored, cornucopia-like, 2 mm. broad, retuse: disk-corollas 2.5 mm. long: 
achenes 3.5-4 mm. long. 
In dry or stony soil, Maryland to Minnesota, Georgia and Texas. Spring and summer. 
