Rao weed Family. !>5 



pink-purple flowers. Waste and cultivated grounds; July-October; common. 

 (A. lappa minus Gray.) 



CNICUS L. Thistle. Biennials or perennials, with sessile alternate 

 leaves, and large terminal discoid heads. Involucre ovoid or spherical; scales 

 numerous, spinous-tipped or unarmed, in many rows. Receptacle bristly. 

 Flowers tubular, perfect. Style nearly undivided. Pappus copious, plumose, 

 deciduous. Achenes oblong, compressed, smooth. 



C. lanceolatus (L.) Willd. ChinmonT, Stem 2-1 feet high; leaves sessile, 

 decurrent, pinnatiSd, hairy above, white-woolly beneath, lobes spiny; heads 

 purple; scales lanceolate, spreading, all tipped with a spine. Waysides and 

 pastures; July-September; common. (Cardans lanceolatus L.) 



C. altissimus (L.) Willd. Stem 2-ii feet high; leaves oblong-ovate to 

 lance-oblong, rough-hairy above, white-woolly beneath, undivided to sinuate- 

 toothed, or sinuate-pinnatifid, lobes or teeth prickly; heads large; scales 

 lance-ovate, outer with spreading spines; flowers purple. Fields and open 

 woods; August-September, common. (Cardans altissimus L.) The variety 

 Fir.ll'ii.vni'l.iTS Gray, is 2-3 feet high; roots tuberous; leaves deeply pinnatifid. 

 Emmet county; reported from Cass, Cherokee. Palo Alto, and Woodbury 

 counties. 



C. discolor Mnhl. Similar to the preceding; leaves deeply pinnatifid into 

 lanceolate or linear segments. Fields and borders; July-September; reported 

 common. Variable and seems to pass int.. the preceding. (Cniru>. ultissim.us 

 illscolor Gray. Cardans discolor (Muhl.) Nutt.) 



C. hillii Canby. Stem 1-2 feet high, simple or branched; root fusi- 

 form; leaves green on both sides, lobed or pinnatifid; lobes rounded, dentate 

 or prickly; lower leaves spatulate-oblong, narrowed to the base or petioled, 

 the upper oblong, sessile and clasping; outer involueral scales ovate lanceo- 

 late, tipped \v4th short bristles, very glutinous on the back, inner narrowly 

 lanceolate and acuminate. Fields; June-July; reported from Story county 

 (Canlinis HUIU (Canby) Porter). 



C. arvensis (L.) Hoffm. CtirjirUiT. Perennial, stem 1-2 feet high, with a 

 lone running root; leaves oblong-lanceolate, sinuate-pinnatifid, prickly, 

 .smooth or slightly woolly beneath; heads small; flowers rose-purple, imper- 

 fectly dioecious; scales triangular, appressed, minute, prickly-pointed. Culti- 

 vated fields; infrequent but widely distributed, {('ardnvs arvensis (L.) Robs.) 



AMBROSIACEAE Rrirhmh. Ragweed Family. 

 Annual or perennial herbs, mostly of a weedy aspect, with alternate 

 loaves or the lower opposite, and small heads of greenish or whitish, 

 monoecious or dioecious flowers. Staminate and pistillate flowers in the 

 same head, or in separate heads. Involueral scales few, separate or 

 united. Receptacle chaffy. Corolla wanting in the pistillate flowers or 

 reduced to a short tube or ring; the calyx-limb none or a mere border; 

 style 2-cleft. Corolla in the staminate flowers tubular, funnelform, or 

 obconic 4- 5-lobed; stamens usually 5, separate, or the anthers merely 

 connivent. A family often included in the Compositae from which it is 

 mostly distinguished by the anthers not being truly syngenesious. 

 * Sbimhitttc and pistillate flowers in the same lieads. 

 Iva. Represented in our flora by a single species. 



