962 CARDUACEAE 



fertile or sterile; corollas campanulate, funnelform, or tnimpet-shapedj 5-toothed, 

 regular; anthers with lanceolate or subulate tips; style either 2-cleft and the 

 branches more or less recurved, truncate at the apex, with an erose or fimbriate 

 apex, or else entire and surmounted by an erose or fimbriate cup; achenes ellip- 

 soid, terete, usually glabrous, without pappus. 



Disk-flowers sterile, their styles xindivided or with short erect branches ; receptacle naked. 

 Annual or perennial herbs; style of the disk-flowers undivided, ending in a cup- 

 shaped penicillate appendix. I. Dracunculoides. 

 Low shrubs or undershrubs; style of the disk-flowers usually more or less 2-cleft, each 

 branch erect with truncate penicillate or erose apex. II. Filifoliae. 

 Disk-flowers fertfle, their styles 2-cleft; branches more or less recurved. 

 Marginal pistiUate flowers present. 

 Receptacle hairy. 



Heads numerous, usually paniculate; plant more or less shrubby at the base. 



III. Frtgidae. 

 Heads few, 1-12, racemose; plant low, herbaceous, from a rootstock, 1-3 dm. 

 ^ bigh. IV. Lanatae. 



Keceptacle naked. 



Annual or biennial herbs with bipinnatifld leaves. V. Annuae. 



Perennials. 



Leaves silvery or silky or glabrate, but not tomentose beneath. 



Plants low, herbaceous perennial, with rootstocks; heads many-flowered^ 

 nodding in a simple racemose inflorescence; leaves divided into Linear 

 or oblong divisions. VI. Nokvegicae. 



, Plants more or less slirubby at the base; heads paniculate. 



Leaves pinnately dissected into narrow divisions (glabrate forms of 



A. Abrotanum, A, graveolens and A. tenuis). 

 Leaves cuneate, 3-toothed at the apex or the upper entire. 



XIII. BIGELOVIANAE. 



Leaves more or less tomentose beneath. 



Leaves not dissected into narrowly linear more or less divergent divi- 

 sions; these, if narrow, very few, directed forward and entire. 

 Leaves greener and glabrate above, at least in age. 



Heads 60-100-flowered; leaves twice pinnatifid with obtuse 



divisions, the lower long-petloled. 



A^II. Franserioides. 

 Heads 5-50-flowered ; leaves simple or once pinnatifid, or if bi- 

 pinnatifld, with acute lobes and sessile or short-petioled. 

 Leaves entire or with a few lobes, if dissected to near the 

 midrib, the lobes rather broad [except in A. mexicana], 



VIII. VULGARES. 



Leases deeply dissected to near the midrib; divisions linear 

 or oblong, usually more or less cleft. 



X. DISCOLORES. 



Leaves white-torn en tose on both sides. IX. Gnaphaloides. 



Leaves once or twice dissected into Unear or filiform, more or less spread- 

 ing divisions. 

 Leaf-segments broadly Hnear or linear-lanceolate, usually again 



lobed or toothed. X. Discolores. 



Leaf-segments narrowly linear or flUform, mostly revolute. 



Leaves once pinnatifid ; plant herbaceous ; style of the ray-flow- 

 ers long-exser ted . XI. Wrightianae. 

 Leaves twice pinnatifid; plant suffruticose; style of the ray- 

 _ _ . , flowers short-exserted. XII. Ponticae. 

 Margmal pistillate flowers wanting; receptacle naked. 



Shrubs 1-50 dm. high; leaves canescent, not with raised midribs. 



Heads in terminal panicles; leaves enth-e, 3-5-toothed to 3-5-divided at the 



apex, XIV. TRTDENTATAE. 



Heads axillary; leaves pinnatifid into linear di\isions. XV. Rigidae. 

 Dwarf undershrubs, scarcely more than 1 dm. high; leaves pinnatifid into Unear- 

 spatulate divisions, green, with the ribs raised beneath. 



XVI. Ptgmaeae. 

 I. Dracxjncxjlotdes. 



Leaves all entire or the lower 3-fid. 



Leaves densely pubescent when young. 1 A glauca 



Leaves glabroiis. 



Involucre 3-4 mm. broad; lower stem-leaves 3-12 mm. wide; heads 3(>-100-flow- 

 ered; outermost involucral bracts almost as long as the inner. 



^ , ^ „ , , , 2. A. aromatica. 



Involucre 2-3 mm. broad; leaves 1-3 mm. wide; heads 20-^0-flowered ; outer 



bracts much shorter than the inner. 3. A. dracunculoides. 

 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; outer bracts acute. 



Plant glabroiis or nearly so. 4. A, caudata. 



