COLOMBIAN EUPATORIUMS. 269 
in Engl. Bot. Jahrb. xix. 45 (1894), xxi. 329-333 (1895), xxix. 5-15 
(1900), xxviii. 564-576 (1901), xJ. 369-389 (1908); Heering in 
Fuhrmann & Mayor, Mém. Soc. neuch&t. Sci. Nat. v. 418-421 (1913). 
For extended synonymy, see Dalla Torre & Harms, Gen. Siphonog. 
527 (1905).— Mostly perennial herbs or erect shrubs, a few annuals, 
a few arborescent or even arboreous, a few shrubby climbers (leaning 
rather than twining). Leaves chiefly opposite, rarely alternate, 
sometimes scattered, in a few species verticellate or perfoliate, in 
contour ranging from filiform to orbicular, in texture from delicately 
membranaceous to coriaceous or rarely to fleshy. Florets clear white, 
pink, purple, or blue, rarely greenish- or yellowish-white. 
A huge genus, most copiously distributed, both as to individuals and 
species in the warmer parts of America, from Mexico to Brazil, also 
well represented in temperate North America and extra-tropical South 
America, and sparingly so in Eurasia, but nearly absent from Africa 
and lacking in Australia. 
Key ro Sections. 
a, Receptacle sage tet b. 
pag ae acle flat or nearly so 
Involucre cylindrical (2-)3°5 times as long as thick; 
osely imbricate in several regularly graduated 
rag at nga’ eadite | deciduous or sometimes sa 
in texture, somewhat scarious except tow 
es usually obtuse or rounded and eae ger subhietba- 
OCEPHALA (p. 270). 
RG i i hes 
¢. Involucre campan anulate or jurbiosi (rarely suis 
but Se with scales in fewer series and less closely im- 
bri gt nin the] “toe section), seldom more than 
as high as 
fall. 0 of the seth ee 
une ual, the outer gradually shorter 
Si = SRGAN ss Sages S Seut : 2. SUBIMBRICATA (p. 281). 
d. Scales subedus - lin 1-2 = "cnet ae : 
olten i-3 of the outermost scales considera 
: Sect Noxon (p. 303). 
b. Receptacle Soe convex, femuaplicrioal: or aie 
Scales — in several series, iy 
caduco ssh maturity, commonl falling aay | ‘am the 
achenes, “Heads few, separate, long-peduncled. Ann 
ros ee Oe ee Sect Praxenis (p. 318). 
€. Scales persistent, at least until after the fall of the ‘achenes. : 
Chiefly perennial herbs or shrubs 
f. Heads small (us wally 4-7 mm igh), mostly 15-30- 
. flowered. Scales pe na ted in 
3-4 series, mostly attenuate to a nhs or 2 ‘east 
fh P25 ap tie gO ene ong a ae Re aot — Into (p. 320). 
eads il (1 em. or more in height), ), 40-1 owere 
Seales subequal in length, finely nerved or many 
me rather than strongly ¢ ibbed. “Sect. VI. Camputocurytom (p. 325). 
tacle hairy, convex.......... Sect. VII. Hesecuunrom (p. 327). 
