TROPICAL AMERICAN EUPATORIEAE 45 
n. Leaves membranaceous s. 
s. Leaves small, 6-14 mm. long, petiolate........34. E. thymifolium. 
s. Leaves 3-6 em. long petiolate t. 
t. Involucral scales squarrose............... 57. E. phyllocephalum. 
t. Involucral scales appressed wu. 
u. Heads 45-50-flowered v. 
v. Involucral scales ciliate but otherwise glabrous, colored toward 
the tip; herb 3-5 dm. high. 2... 3. 6.52... . E. toldepse. 
v. Scales tomentose on back; shrub 1-3 m. high..35. E. Lobbii. 
u. Heads 20-30-flowered w: 
eads in an open usually diffuse panicle, not glomerate, del- 
; annual... ..36. E. microste? 
deltoid-ovate, usually crenate-serrate. .37. E. pycnocephalum. 
w. Heads borne in 2-5-heade 
branches of a lax leafy-bracted panicle; leaves lance-ovate, 
acutely serrate; perennial or ruticose 2. 
x. Leaves scabrid above, scabrous on nerves beneath; ‘apr 
ensely puberulent; branchlets covered with purple glan- 
dular pubescence; innermost waldenes tes 0.75 mm. 
tam 
smooth or with sparse non gl 
andular pubescence; inner- 
most scales 1—-1.3 mm. wide, elliptic: 
al-oblong 
is dee e. 
w. Heads numerous in rather dense terminal flattish corymbs y 
y. Leaves rounded or subcordate at base; petioles densely 
sticky-glandular; inner involucral scales ex 
. E. Fiebrigit. 
y. Leaves obtuse or acute at base, glabrous snare young parts 
5 . Pentlandianum. 
y. Leaves attenuate at base, covered above with scabrous in- 
Vv r somewhat papillose puberulence; inner scales 
—2-costulat . EB. Bridgesit. 
s. Leaves 9-27 em. long, sessile by an attenuate petiole-like base z. 
@ ; ous 
. Corollas hirsutul toward the limb; sare about 36-flowered; 
rous . E. triosteifolium. 
z. Corollas glabrous; pedicels and branchlets glandular; heads 200- 
300-flowered; receptacle oblate-ellipsoidal, minutely pubescent 
: 68. nemorosum. 
13. E. buniifolium Hook. & Arn. Smooth fastigiately much 
branched shrub sometimes as much as 2.5 m. high; leaves opposite 
and excessively variable being either simple and linear or often on the 
same individual in different degrees deeply pinnatifid with linear seg- 
ments; heads 5(-6)-flowered, slender-pedicelled, often nodding, in 
leafy-bracted panicles; involucral scales 12-17 lanceolate, purplish- 
brown and striatulate toward the narrowed but mostly rounded or 
merely acutish tip, stramineous and usually 3-costulate below the 
middle; corollas 4-5 mm. long, the gradually enlarged throat about 
