246 NORTH AMERICAN FLORA 
Leaves once pinnatifid; plant herbaceous, 
woody only at the base, if at all; style 
of the ray-flowers long- exserted. XIV 
Leaves twice pinnatifid; plant suffru- 
tescent; style of the ray-flowers 
short-exserted. 
Heads numerous, small, less than 5 mm. 
broad, in leafy panicles; leaves twice 
pinnatifid, with filiform divisions. XV 
Heads fewer, comparatively large, 5 
mm. broad or more; primary divis- 
ions of the leaves ternately cleft 
into linear or oblong divisions. ExcVale 
Marginal pistillate flowers wanting; receptacle naked. D. Seri- 
phidium. 
Shrubs, 1-50 dm. high; leaves canescent, not with raised midribs. 
Heads in terminal panicles; leaves entire, or 3—5-toothed to 
3—5-divided at the apex. XVITI. 
Heads axillary; leaves pinnatifid into linear divisions. XIX. 
Dwarf undershrubs, scarcely more than 1 dm. high; leaves pin- 
natifid into linear-spatulate divisions, green, with the ribs 
raised beneath. xX. 
Subgenus A. Dracunculus 
I. DRACUNCULOIDES 
Leaves all entire or the lower 3-fid. 
Heads in dense panicles with erect or ascending branches. 
Leaves densely pubescent when young. Ae 
Leaves glabrous. 
Involucre 3—4 mm. broad; lower stem-leaves 3-12 mm. wide. 
Outermost involucral bracts about half as long as the inner- 
most; heads 20-49-flowered. 2: 
Outermost involucral bracts almost as long as the innermost; 
heads 30—100-flowered. 3: 
Involucre 2-3 mm. broad; leaves 1-3 mm. wide; heads 20—40- 
flowered; outer bracts much shorter than the inner. 
Branches of the inflorescence strict. 4, 
Branches of the inflorescence drooping at the apex. Sh 
Heads in open panicles, 20—25-flowered. 
Branches ascending, nodding at the apex; plant glabrous from the 
beginning. Bs 
Branches spreading; leaves and stem often pubescent when young, 
glabrate in age. 
Pubescence of long loose hairs. 6. 
Pubescence of short appressed hairs. Te 
Leaves, at least the lower, pinnatifid or bipinnatifid. 
Heads very small, 2-3 mm. broad, numerous in large leafy panicles; 
plants mostly tall, 3-10 dm. high. 
Biennials; heads mostly erect, the outer bracts acute. 
Plant glabrous or nearly so. 8. 
Plant decidedly pubescent. 9. 
Perennials, with a rootstock or caudex; heads nodding at least at 
rst. 
Plant 3-10 dm. high; stem leafy. 
Stem tall, very leafy, 4-10 dm. high; bracts acute or acutish. 10. 
Stem lower, 3—5 dm. high; stem-leaves rather small and 
scattered; bracts obtuse or rounded at the apex. 
Plant decidedly appressed-silky; inflorescence dense. Le 
Plant glabrate; inflorescence open. We 
Plant less than 1 dm. high; stem scapiform; stem-leaves 
minute. 34. 
Heads larger, 4-5 mm. broad, not very numerous (except in A. Bour- 
ree in narrow spike-like panicles; plants low, rarely 3 dm. 
i 
Tawvaliocal bracts glabrous or nearly so; disk-corollas glabrous. 
Outer involucral bracts about half’ as long as the inner; stem 
strict. 13: 
Outer involucral bracts nearly as long as the inner; stem de- 
cumbent at the base. 14. 
Involucral bracts more or less villous; disk-corollas usually with a 
few hairs on the lobes. 
Leaves silky-canescent with appressed hairs. 
Plant 3-4 dm. high; heads very numerous in a dense panicle. URE, 
Plant 1-3 dm. high; heads fewer, usually a spike-like panicle 
or racemose. 
Segments of the basal leaves linear-oblanceolate. 
Basal leaves 2-4 cm. long, usually not densely white- 
silky; stem 1-2. 5 dm. high. 16. 
Basal leaves 1—2 cm. long, densely and finely white- 
silky; stem 5-6 em. high. 7 
[VoLUME 34 
. WRIGHTIANAE. 
. PONTICAE. 
RUTAEFOLIAER, 
‘TRIDENTATAE. 
RIGIDAE. 
PYGMAEAE. 
Es 
me 
. glauca, 
. Dracunculus. 
. avomatica. 
. dracunculoides. 
. cerynua. 
. ceynud. 
. dracunculina, 
- gracillima. 
. caudata. 
. Forwoodit. 
. pacifica. 
. camporum. 
. campestris. 
- minuta. 
. MacCallae. 
- canadensis. 
. Bourgeauana. 
. Spithamaea. 
. manca,. 
