CARDUACEAE 1 289 



branches spreading, 1-3 dm. long : leaves alternate ; blades linear or linear-spatulate, 1-4 

 cm. long, entire : peduncles very slender or filiform, 3-12 cm. long : involucral bracts ob- 

 long or almost linear, 3-3.5 cm. long: ligules of the ray-flowers 6-8 mm. long. 

 In dry rocky soil, Kansas to Louisiana, Texas and New Mexico. Spring and summer. 



2. Tetraneuris linearis (Nutt. ) Greene. Perennial, pubescent. Caudex branched 

 at the base, the branches tufted : leaves crowded on the caudex-branches ; blades linear or 

 narrowly linear-spatulate, 2-5 cm. long, acute, entire : scapes erect, 1-3 dm. tall, usually 

 several together, simple : involucral bracts oblong or oblong-cuneate, 3-4 mm. long, ob- 

 tuse : ligules of the ray-flowers 8-15 mm. long. 



In dry soil, Arkansas to New Mexico and adjacent Mexico. Spring to fall. 



121. PICRADENIA Hook. 

 Annual caulescent herbs, usually pubescent. Leaves alternate : blades pinnately 

 divided, the segments narrow. Heads heterogamous, radiate. Involucre of 2 series of 

 bracts, those of the outer series united at the base. Receptacle convex or conic, naked. 

 Ray-flowers pistillate, fruit-producing, with yellow ligules. Disk-corollas perfect, fruit- 

 producing. Stigmas truncate and brush-like at the apex. Achenes broadened upward, 

 pubescent. Pappus of several awned or merely acuminate scarious scales. 



1. Picradenia odorkta (DC.) Britton. Annual, more or less pubescent. Stem 3-6 

 dm. tall, usually branched at the base and above, the branches ascending : leaf-blades 1-3- 

 parted into linear-filiform ultimately entire segments : heads few or numerous, slender- 

 peduncled : involucre broadly campanulate, 3-4 mm. high ; bracts various, the outer ovate 

 or oblong-ovate beyond the slightly contracted and slightly united bases, the inner broader, 

 acute : ligules of the ray-flowers cuneate, 5-8 mm. long. 



In dry soil, Kansas to California, Texas and Mexico. Spring and summer. 



122. FLAVIJRXA Juss. 



Annual caulescent herbs. Leaves opposite : blades entire or toothed, sessile. Heads 

 small, radiate or discoid, usually sessile. Involucres narrow, 1-several-flowered : bracts 

 few, often 2-5, equal, narrow. Receptacle naked. Ray-flowers mostly solitary, pistillate, 

 fruit-producing : ligules yellow, or wanting. Disk-flowers 1-15, perfect, fruit-producing : 

 corollas yellow or yellowish. Anthers entire at the base. Stigmas of the disk-flowers 

 truncate. Achenes narrow, 8-10-ribbed. Pappus wanting. 



Involucres of J-5 principal bracts, 4-15-flowered. 



Involucres mostly of 5 bracts. 1. F, linearis. 



Involucres mostly of 3 bracts. 2. F. anpustifolia. 



Involucres of 1-3 principal bracts, 1-2-flowered. 3. F. repanda. 



1. Flaveria linearis Lag. Foliage somewhat pubescent. Stems 2-9 dm. long, some- 

 times decumbent, corymbose above : leaf-blades narrowly linear or lanceolate, 3-10 cm. 

 long, narrowed above the connate bases, entire : heads numerous : involucres narrow, 4 

 mm. high ; bracts mostly 5, oblong or lanceolate, acute : ray-flowers usually solitary ; lig- 

 ule oblong to oval, 2-3.5 mm. long: disk-flowers usually 5-8. 



In sand, peninsular Florida. Also in the West Indies. 



2. Flaveria angustifolia (Cav. ) Pers. Foliage nearly glabrous. Stems 3-9 dm. 

 tall, branching above : leaf-blades linear to lanceolate or oblong-lanceolate, 3-7 cm. long, 

 acute or acuminate, serrate or nearly entire, lightly 3-nerved, sessile : heads in terminal 

 involucrate clusters : involucres 4-5 mm. high ; bracts usually 3 : ray-flowers mostly soli- 

 tary ; ligule oblong-cuneate, 1.5-2.5 mm. long : disk-flowers 1-4. 



In alkaline soil, Kansas and Colorado to Texas, New Mexico and Mexico. 



3. Flaveria repanda Lag. Foliage glabrous. Stems 2-9 dm. tall, widely branched : 

 leaf-blades linear-elliptic to broadly linear, 3-10 cm. long, acute or somewhat acuminate, 

 serrate, 3-nerved, narrowed to the sessile but barely connate bases: heads in axillary or 

 involucrate clusters : involucres 1-2-flowered, narrow, 3-4 mm. high ; bracts 1-3, or some- 

 times accompanied by a few accessory ones : ray-flowers usually solitary in the outer heads. 



In sandy soil, Florida and Texas to adjacent Mexico. 



123. LAPHAMIA A. Gray. 



Perennial caulescent herbs or shrubby plants, with pubescent foliage. Leaves oppo- 

 site or alternate above : blades toothed or incised. Heads radiate or rarely discoid, some- 

 times in corymbs. Involucres campanulate or nearly hemispheric : bracts imbricated, in 



