1290 CAEDUACEAE 



1 or 2 series, nearly equal. Receptacle convex, naked. Ray-flowers pistillate, fruit-produc- 

 ing : ligules yellow, or rarely wanting. Disk-flowers perfect, fruit-producing : corollas with 



4 lobes. Anthers sagittate at the base. Stigmas of the disk-flowers with pubescent subu- 

 late appendages. Achenes flattened, with ciliate or cartilaginous margins. Pappus of 

 1 or 2 longer bristles often with small bristles between, or sometimes crown-like. 



1. Laphamia Lindbeimeri A. Gray. Foliage finely but closely pubescent. Stems 

 1-3 dm. tall, corymbosely branched : leaf-blades ovate to oblong, 1-2 cm. long, glabrate, 

 acute, entire or shallowly serrate, cuneate or truncate at the base, petioled : heads about 



5 mm. high : involucres campanulate ; bracts linear or slightly enlarged upward : ray- 

 flowers 3-6 or wanting : pappus a slender bristle about as long as the corolla-tube. 



On rocky banks, Texas. 



124. HELENIUM L. 



Annual, biennial or perennial caulescent bitter herbs. Leaves alternate : blades entire 

 or toothed, often decurrent on the stem. Heads radiate or rarely discoid, peduncled. In- 

 volucres flattish : bracts narrow, in 1 or 2 series, spreading or reflexed. Receptacle con- 

 vex, oblong or subglobose, naked. Ray-flowers pistillate and fruit-producing, or neutral : 

 ligules yellow or brown at the base. Disk-flowers perfect, fruit-producing : corolla yellow, 

 purple or brown, with glandular lobes. Anthers 2-toothed or sagittate at the base. Stig- 

 mas of the disk flattened and truncate. Achenes broadened upward, truncate. Pappus of 

 5-8 entire, toothed or lacerate acuminate or awn-tipped scales. Sneezeweed. 



Kay-flowers pistillate. 



Plants annual or sometimes biennial. 



Leaf-blades narrowly linear or linear-flliform, not decurrent. 



Disk yellow : leaves with entire blades. '1. H. tenuifolium. 



Disk purple-brown : some of the lower caullne leaves with pinnately 



parted blades. 2. H. badium. 



Leaf-blades broader, all or some of them conspicuously decurrent on the 

 stem. 

 Disk oblong or ovoid. 



Receptacle conic or oblong-cylindric : disk becoming much longer 



than thick. 3. H. quadi-identatum. 



Receptacle ovoid :'disk but little longer than thick. 4. II. oodinum. 



Disk globular. 



Mature disk 4-6 mm. in diameter. 



Receptacle depressed : pappus-scales shorter than the width of ' 



the achene. 5. H. elegans. 



Receptacle conic-ovoid : pappus-scales about % the length of the 



achene. ~ 6. II. microcephalum. 



Mature disk 8-10 mm. in diameter. 7. //. amphibolum. 



Plants perennial. 



Receptacle ovoid or conic. 



Wings of the upper part of the stem and the branches 1 mm. wide or 

 less : receptacle ovoid. 

 Receptacle 2.5-3.5 mm. high : ligules of the ray-flower 6-15 mm. long. 



Disk yellow. 8. II. parviflorum. 



Disk brown or purple. 9. H. nudiflorum. 



Receptacle 6-7 mm. high : ligules of the ray-flowers 25-30 mm. long. 10. H. campestre. 

 Wings of the upper part of the stem and the branches over 2 mm. wide : 



receptacle conic. 11. II. polyphyllum. 



Receptacle hemispheric or depressed. 12. H. autumnalc. 



Ray-flowers neutral. 



Receptacle ovoid or ovoid-conic : disk globular or globose-spheroidal. 



Disk about 1.5 cm. broad : ligules with slender, acute segments : pappus- 

 scales dissected to about the middle. 13. H. fimbriatum. 

 Disk about 2 cm. broad : ligules with broad, obtuse segments: pappus- 

 scales nearly entire. 14. II. Ciirti$ii. 

 Receptacle flattish or depressed-hemispheric : disk similar. 

 Disk yellow. 



Leaf-blades entire or merely undulate. 15. //. Hdenium. 



Leaf-blades sinuate-dentate or pinnatifid. 



Achenes glabrous. 16. H. incisum. 



Achenes pubescent. 17. H. vernalc. 



Disk purple or brown. 18. II. brei'i/olium. 



1. Helenium tenuifolium Nutt. Annual, glabrous or sparingly pubescent above. 

 Stems 2-4 dm. tall, often branched into a bushy head : leaves numerous ; blades narrowly 

 linear, 1-5 cm. long, usually entire, not decurrent : heads showy : involucral bracts linear- 

 subulate, 4-6 mm. long, spreading or reflexed : ray-flowers few ; ligules yellow, 6-7 mm. 

 long, 3-4-toothed : disk yellow, 6-8 mm. broad : pappus-scales ovate, prolonged into slender 

 tips. 



In waste places and moist soil, Virginia and Missouri to Florida and Texas. Naturalized east- 

 ward. Summer and fall. 



