222 COMl'OSITyE. (oOMrOSITE FAMILY.) 



2. B. SUbacaulis, Nutt. Ronirh-jmhcsccnt and somewhat hoary; leaves 

 cliiufly railii-al, clustered, sinuatc-pinnatilid ; heads solitary on the ])ediinele-likc 

 stem, or few on the pedunele-like branches of the short and nearly leafless stem. 



— East Florida aud (Jeor-ia. May - Auyust. — Teduuelc 6' - b' long. Leaves 

 3' long. 



34. PAKTHENIUM, L. 



Heads many-flowered ; the ray-flowers 5, in a single row, short, obeordatc, 

 pistillate; those of the disk tubular, 5-toothed, sterile. Anthers .slightly united. 

 Scales of the involucre in two rows, ovate or roundish. Receptacle coiucal, 

 chaffy ; the chaff dilated upward. Achenia smooth, compressed, thick-mar- 

 gined. Pappus of two awu-likc or roundish scales. — Herbs. Leaves alternate. 

 Flowers white. 



1. P. integrifolium, L. Perennial; stem erect, sinii)le, rou-h ; leaves 

 undivided, ovate or oblong-ovate, serrate ; the lowest narrowed into a long 

 petiole; panicle dense, corymbose ; involucre hoary; i)aj)pus minute, awn-like. 



— Dry soil among the mountains, Alabama, and northward. August. — Stem 

 l°-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 jianieled ; scales of the pap- 

 pus oval. — Waste places. East and South Florida, aud westward. 



35. IVA, L. 



Heads few- or many-flowered ; the flowers all tu])nlar ; tlic marginal ones 

 (1-5) with a short corolla, pistillate and fertile; the central ones 5-tooihed, 

 sterile. Anthers nearly distinct. Scales of the involucre 3-5, in a single row, 

 oval or obovate, distinct or partly united, or 6 - 9 and imbricated. Chaff of the 

 small receptacle linear or spatulate. Achenia biconvex, obovate. Pa])pus 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, in a simjhi roio. 



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 

 4°- 8° high. 



2. I. microcephala, Nutt. Annual, rough with rigid appressed hairs ; 

 stem slender, much branched ; leaves narrow-linear, entire ; iieads minute, 6 - 

 12-flowered ; scales of the involucre 4-5, obovate, ciliate ; fertile flowers 1-3. 



— Dry barren soil, Florida to South Carolina. Aug. and Sejit. — Stem I°-2° 

 high. 



* * Sciihs of the inrolitcre Ci-9, iiiilirirafal in 2-4 rows. 



3. I. irabricata, Walt. Somewhat shrubby, smooth ; leaves fleshy, lance- 

 olate, the Idwrr urns sli^'htly serrate and 3 ribbed, the upper alternate and entire; 

 hciuls maiiy-dowercd ; outer scales of the involucre orbicular ; the inner obovate, 



