222 COMPOSITA. (COMPOSITE FAMILY.) 
2. B. subacaulis, Nutt. Rough-pubescent and somewhat hoary; leaves — 
chiefly radical, clustered, sinuate-pinnatitid ; heads solitary on the peduncle-like 
stem, or few on the peduncle-like branches of the short and nearly leafless stem. 
— East Florida and Georgia. May- August. — Peduncle 6/-8/long. Leaves 
3! long. 
34. PARTHENIUM, L. 
Heads many-flowered ; the ray-flowers 5, in a single row, short, obcordate, 
pistillate ; those of the disk tubular, 5-toothed, sterile. Anthers slightly united. 
Scales of the involucre in two rows, ovate or roundish. Receptacle conical, " 
chaffy ; the chaff dilated upward. Achenia smooth, compressed, thick-mar- 
gined. Pappus of two awn-like or roundish scales. — Herbs. Leaves alternate. 
Flowers white. 
1. P. integrifolium, L. Perennial; stem erect, simple, rough; leaves — — 
undivided, ovate or oblong-ovate, serrate ; the lowest narrowed into a long 
petiole ; panicle dense, corymbose ; ihvelusvé hoary ; pappus minute, awn-like. 
— Dry soil among the mountains, Alabama, and northward. August. — Stem 
19-2? high. Lowest leaves 4/—6'long. Rays conspicuous. 
2. P. Hysterophorus, L. Annual, pubescent; stem diffuse ; leaves 
pinnatifid, with linear toothed lobes ; heads loosely panicled ; scales of the Perr 
pus oval. — Waste places, East and South mires. and westward. 
35. IVA, L. 
Heads few- or many-flowered; the flowers all tubular ; the marginal = 
(1-5) with a short corolla, pistillate and fertile; the central ones 5-toothed, 
sterile. Anthers nearly distinct. Scales of the involucre 3-5, in a single TOW, 
oval or obovate, distinct or partly united, or 6-9 and imbricated. -Chaff of the 
small receptacle linear or spatulate. Achenia biconvex, obovate. Pappus none. 
— Branching herbs or shrubs, with opposite or (the upper) alternate mostly 
fleshy leaves, and small axillary nodding heads of whitish flowers. 
* Scales of the involucre 3-5, ina single row. 
1. I. frutescens, L. Shrubby; leaves lanceolate or oblong, sharply 
toothed-serrate, 3-ribbed, smoothish ; scales of the involucre 5, orbicular ; fertile 
flowers 5. — Saline marshes, Florida, and northward. Aug. and Sept. — Shrub 
49 - 8° high. 
2. I. microcephala, Nutt. Annual, rough with rigid appressed hairs; - 
stem slender, much branched; leaves narrow-linear, entire; heads minute, 6- 
12lowered ; scales of the involucre 4 —5, obovate, ciliate; fertile flowers 1-3 
MR barren soil, Florida to South Carolina. Aug. and Sept. — Stem vat 
d. und 
T Ut Seales of e iare - -9, imbricata in 2- 4 rows. 
PY ins > 
