1164 CARDUACEAE 
what squarrose, the inner azure: corolla purplish blue or reddish : achenes 2 mm. long, 
glabrous or nearly so, wing-angled. [Eupatorium ivaefolium L. ] 
In old fields, Mississippi to Texas and Mexico. Also in tropical America. Fall. 
2. Osmia heteroclina (Griseb.) Small. Minutely pubescent. Stems 5-10 dm. 
tall, branching: leaf-blades ovate-lanceolate to deltoid-ovate, 2-3 cm. long, rather obtuse, 
serrate, cuneate to truncate at the base: involucres cylindric, 8-12 mm. long, 20-25-flow- 
ered ; bracts ovate to oblong, obtuse, appressed, shining, faintly ridged: corolla blue or 
purplish: achenes 3-3.5 mm. long, nearly glabrous. [Eupatorium heteroclinum Griseb. ] 
In sand, Florida Keys. Also in Jamaica. 
3. Osmia conyzoides (Vahl) Small. More or less densely pubescent. Stems 6-18 
dm. tall, much branched : leaf-blades ovate to lanceolate, 4-10 cm. long, acuminate, nearly 
entire or coarsely serrate, commonly cuneate at the base: involucres cylindric, 8-10 mm. 
high, 12-30-flowered ; bracts ovate to oblong or linear-oblong, 5-7-ridged, the outer ob- 
tuse, the inner often acute: corollas white or pale blue: achenes 3.5-4 mm. long, nearly 
glabrous, sharply angled. [Eupatorium conyzoides Vahl. ] 
In sand, Florida to Texas. Also in tropical America. 
10. EUPATORIUM L. 
Annual or (all within our range) perennial caulescent herbs or shrubby plants, none 
vines. Leaves alternate, opposite or sometimes whorled : blades various, entire, toothed 
or dissected. Heads usually in corymbs. Involucres mostly narrow: bracts scarious to 
membranous, or herbaceous in one series or several, rarely inconspicuously ribbed. Re- 
ceptacle flat, naked. Corollas regular, white to purple. Anthers appendaged at the apex, 
obtuse at the base. Stigmas elongated, obtuse, flattened or thickened above. Achenes 5- 
angled, truncate. Pappus of numerous hair-like bristles in 1 series. 
Leaf-blades mainly dissected into filiform or narrow segments or sometimes deeply pinnatifid. . 
Leaf-segments filiform. 1. E. capillifolium. 
Leaf-segments linear, linear-filiform or narrowly lanceolate. 
Leaf-blades 1-2-parted. 
Inflorescence paniculate or thyrsoid : 
Heads 3-6-flowered: not glomerate on the inflorescence-branches: thay 
bracts of the involucre punctate and viscid. 2. E. compositifolium. 
Heads 6-9-flowered : glomerate or clustered at the ends of the inflor- 
escence branches: bracts of the involuere neither punctate nor , 
viscid. 3. E. Eugene. 
Inflorescence corymbose. . E. pinnatifidum. 
Leaf-blades mainly pectinately pinnatifid. 5. E. pectinatum. 
Leaf-blades merely toothed or incised. 
Leaves opposite or alternate, or rarely in 3's in 1 or 2 narrow-leaved species. 
Leaf-blades manifestly petioled. 
A 
Larger leaf-blades fully twice as long as broad. 6. E. serotinum. 
Larger leaf-blades but little longer than broad. ig pater 
Heads 5-flowered. 7. E. mikanioides. 
Heads 10-30-flowered. 
Shrubby p plants. S k 
Leaf-blades entire or merely repand : involucres 34 mm. high. 8. E. villosum. 
Leaf-blades coarsely toothed : involucres 4-5 mm. high. 9. E. ageratifolium. 
Herbaceous perennial plants. ; 
Corolla w olly glabrous. 10. E. incarnatum. 
orolla with persistently bearded lobes. ; 
Leaf-blades acuminate, 11. E. ageratoides. 
Leaf-blades obtuse or abruptly acute. 12. E. aromaticum 
Leaf-blades sessile or essentially so, or connate-perfoliate. R 
A. Leaf-blades neither connate-perfoliate nor connate-clasping. 
Base of the leaf-blade not broader than the rest of the blade or gradu- 
ally narrowed. 
Bracts of the involucre obtuse. 
Leaf-blades linear, entire or shallowly and irregularlyjtoothed. 
Leaf-blades less than 1 mm. wide in their normally involute lium 
condition. 18. E. lecheacfor’ s^ 
Leaí-blades over 2 mm. wide, flat. 14. E. hyssopifolium. 
Leaf-blades lanceolate. oblong, ovate or oval, markedly toothed, 
except in E. tortifolium. 
Lower MM broadest below the middle or about at the 
middle. 
bis ans Jeaf-blades toothed from near the base to the apex. 
eaf-blades shallowly and irregularly toothed, 
Leaves spreading : involucres over 4 mm. high. 15. E. Torrey —— 
Leaves reflexed : involucres less than 4 mm. high. 16. E. recurt eis 
Leaf-blades deeply and regularly toothed. 17. E. anomalum. 
CE leaf-blades toothed above the middle. 
nvolucres 3-4 mm. high, less than 2 mm. thick. 
Stem glabrous, except sometimes near the inflores- 
cence: involucres 3 mm. high. 18. -E. lancifolium. 
