CARDUACEAE 1285 
3-5-ribbed thick blades, narrowed into petiole-like bases, upper cauline leaves rather 
remote, much reduced : heads long-peduncled, many-flowered : involucre 7-10 mm. high ; 
bracts nearly oblong, or oblong-lanceolate, acute : corolla-tube about 10 mm. long, the 
upper third dilated into a throat: achenes 3.5-5 mm. long: pappus-scales about J as long 
as the achene, entire. 
In moist soil, in the mountains, Pennsylvania to West Virginia and North Carolina. Summer. 
9. Marshallia trinérvia ( Walt.) Porter. Stem 3-7 dm. tall, usually simple: leaves 
few, the basal and lower cauline 5-12 em. long with mainly spatulate or oblanceolate thin 
3-ribbed blades, the upper cauline slightly smaller than the lower, elliptic, ovate or ovate- 
lanceolate, distinctly 3-ribbed : heads long-peduncled, many-flowered : involucre about 1 
em. high ; bracts linear-lanceolate, decidedly acute: corolla-tube 7-8 mm. long, the upper 
third or fourth dilated into a throat: achenes 2-2.5 mm. long: pappus fully 3 as long as 
the achene, entire. 
In dry or moist soil, Virginia to Tennessee, Alabama and Mississippi. Spring and summer. 
112. GALINSOGA R. & P. 
Annual caulescent herbs. Leaves opposite: blades simple, toothed. Heads radiate, 
inconspicuous. Involucres campanulate or hemispheric: bracts imbricated in two series, 
thin, the inner sometimes longer than the outer. Receptacle conic, or somewhat elongated, 
chaffy. Ray-flowers 4-5, pistillate, fruit-producing : ligules white, very short. Disk-flow- 
ers perfect, fruit-producing: corollas yellow. Anthers sagittate at the base. Stigmas 
with acute appendages. Achenes broadened upward, 4—5-angled, or the outer ones slightly 
flattened. Pappus various; that of the ray of several bristles, or wanting; that of the 
disk of several lacerate or fimbriate scales. 
1. Galinsoga parvifldra Cav. Foliage hispidulous or glabrate. Stems 1-7 dm. tall, 
succulent, often branched : leaf-blades ovate to ovate-lanceolate, 2-5 cm. long, acute, ser- 
rate-dentate or undulate, petioled: heads inconspicuous: involucres campanulate, 2-2.5 
mm. high; bracts ovate, ciliate: ray-flowers few; ligules white, 1-1.5 mm. long, the 
segments ovate : achenes cuneate, barely 2 mm. long, the inner ones with 8-15 pappus scales. 
In waste places, Massachusetts to Oregon, Georgia and Mexico. Naturalized from South America. 
113. TRIDAX L. 
Perennial caulescent herbs, usually branched at the base. Leaves opposite: blades 
incised-toothed or pinnately dissected into narrow segments. Heads heterogamous, long- 
peduncled, radiate. Involucre ovoid to campanulate: bracts in few series. Receptacle 
flat or somewhat convex, chaffy. Ray-flowers pistillate, fruit-producing. Disk-flowers 
perfect, fruit-producing. Anthers auricled-sagittate at the base. Stigmas of the perfect 
flowers pubescent at the apex and with subulate appendages. Achenes broadened up- 
ward, usually pubescent. Pappus of numerous aristate-aeuminate plumose-ciliate scales. 
1. Tridax procümbens L. Stem branched at the base, the branches spreading or 
decumbent, more or less hirsute: leaf-blades ovate in outline, 2-5 cm. long, acute, incised 
or incised-lobed, copiously pubescent, cuneate at the base : peduncles mostly 2-3 dm. long : 
involucres solitary, 5-7 mm. high: bracts hispidulous, the outer lanceolate, acuminate, 
the inner broadly oblong or oblong-obovate, mucronate: disk almost 1 em. broad at matu- 
rity : achenes silky, 2 mm. long. 
In sand or coral rock, Florida Keys. Native of tropical America. 
114. CLÁPPIA A. Gray. 
Perennial shrubby but fleshy plants. Leaves alternate: blades entire or pinnately 
3-5-parted. Heads radiate, peduncled. Involucres hemispheric : bracts leathery, imbri- 
cated in 2-3 series, broad, obtuse. Receptacle convex, bristly-fimbrillate. Ray-flowers 
12-15, pistillate, fruit-producing: ligules narrow, yellow. Disk-flowers perfect, fruit-pro- 
ducing. Anthers entire at the base. Stigmas of the disk with triangular appendages. 
Achenes narrow, terete, 8-10-nerved, hairy on the nerves. Pappus of 20-25 scale-like his- 
pidulous bristles longer than the achene. 
l. Clappia suaedaefdlia A. Gray. Shrubby, glabrous. Stems 2-4 dm. tall, widely 
branched : leaf-blades linear, terete, 1-1.5 cm. long, entire or the lower ones pinnately 
3~5-parted, sessile: heads solitary : involucre 6-8 mm. high ; bracts narrow, soon reflexed : 
