1282 CARDUACEAE 
of the involucre linear-spatulate, equalling the disk, glabrous, the inner usually black- 
punctate: rays several, the ligules 1-3 cm. long, golden yellow, the ovaries glabrous and 
awnless: disk-corollas 5-lobed: stamens exserted: achenes very small, 2-4 mm. long, 
glabrous; awns very short, tooth-like. [Coreopsis aurea Ait. ] 
In wet soil, Virginia to Florida and Alabama. Summer and fall—B. coronata leptophylla (Nutt.) 
C. Mohr, a form with narrowly linear and almost or quite entire leaf-segments: and awnless achenes, 
occurs in brackish places from Florida north ward. 
107. CÓSMOS Cav. 
Annual or perennial caulescent herbs. Leaves opposite: blades entire, lobed or 2-3- 
pinnately dissected. Heads radiate, peduncled. Involucres nearly hemispheric : bracts 
thin, imbricated in two series and united at the base, the outer sometimes smaller than the 
inner. Receptacle flat or scarcely convex. Ray-flowers neutral: ligules pink, purple (or 
rarely orange-yellow). ^ Disk-flowers perfect, fruit-producing : corollas yellow. Anthers 
entire or minutely 2-toothed at the base. Stigmas of the disk-flower with slender or tufted 
appendage. Achenes 5-angled or flattened on the back, beaked. Pappus of 2-4 more or 
less persistent barbed awns or a crown. 
1. Cosmos caudatus H.B.K. Annual, glabrous or nearly so. Stems 7~14 dm. tall, 
branched: leaf-blades 2-pinnately parted, the segments lanceolate or linear : involucral 
bracts linear, acute, the inner often longer than the outer: ray-flowers 7-12 ; ligules rose- 
colored, 1-2 cm. long, 3-cleft : achenes fusiform, about 2 mm. long, the beak about as long 
as the body, with 2 awns. 
In sand, Keys of Florida. Native of tropical America. 
108. THELESPERMA Less. 
Annual or perennial herbs, with glabrous or nearly glabrous foliage. Leaves oppo- 
site: blades narrow, entire, toothed or finely dissected. Heads radiate or sometimes dis- 
coid, peduncled. Involucres campanulate or hemispheric : bracts in two series, the outer 
distinct, spreading, the inner larger, partially united into a cup, the tips scarious. Recep- 
tacle flat, chaffy. Ray-flowers neutral: ligules yellow, or wanting. Disk-flowers perfect, 
fruit-producing. Anthers entire at the base. Stigmas with acute cones or cusps. Achenes 
narrow, terete or slightly flattened, wingless, some or all of them papillose on the back. 
Pappus of two retrorsely hispid awns or scales, or wanting. 
Disk-corollas with linear or lanceolate lobes longer than the campanulate throat. 
Annual or biennial : outer involucral bracts linear-subulate. 1. T. trifidum. 
_ Perennial : outer involucral bracts ovate or oblong. 2. T. gracile. , 
Disk-corollas with ovate or oblong lobes, shorter than the cylindric throat. 3. T. subsimplicifolium. 
1. Thelesperma trifidum (Poir.) Britton. Annual or biennial. Stems 2-7 dm. 
tall, loosely branched : leaf-blades 3-10 cm. long, 2-pinnately divided, the segments linear- 
filiform or filiform, not broader than the rachis: involucral bracts various, the outer 
linear-subulate, the inner united to the middle, usually fully as long as the outer: ray- 
flowers 6-9; ligules yellow, 1-1.5 cm. long: disk purple, turning brown : achenes of the 
outer part of the disk 4 mm. long, strongly papillose on the back : pappus-scales triangular- 
subulate, as long as the width of the achene. 
On dry hills and plains, Arkansas and Texas. Spring and summer. 
2. Thelesperma grácile (Torr.) A. Gray. Perennial. Stems 3-8 dm. tall, sparingly 
branched : leaf-blades 3-7 dm. long; blades 1-2-parted or divided, the segments entire, 
filiform or narrowly linear: involucral bracts various, the outer 4-6, ovate or oblong, the 
inner united to above the middle; ligules of the ray-flowers yellow, 4-6 mm. long, OT 
wanting: disk yellow, turning brown : achenes 6-6.5 mm. long, the slender awns longer 
than the width of the achenes. 
On plains, Wyoming to Nebraska, Texas and Arizona. Spring and summer. 
3. Thelesperma subsimplicifolium A. Gray. Perennial. Stems 3-7 dm. tall, 
loosely branched : leaf-blades 3-8 cm. long, entire and narrowly linear or Iinear-filiform 
or 3-5-parted, the segments as wide as the rachis entire: involucral bracts various, the 
outer linear to oblong, the inner united to about the middle: ligules of the nye 
yellow, cuneate, 10-12 mm. long : achenes fusiform, 4-5 mm. long : pappus obsolete, or 9 
2 minute pubescent teeth. 
In dry or stony soil, Texas to Arizona and adjacent Mexico. Spring and summer. 
