APPENDIX A. 



Species of Vernonia occurring North of Mexico. 

 Geuus VERNONIA 



Subgenus LiBPIDAPLiOA. Pappus in two series; bracts of the in- 

 volucre in several to many series. 



A. CAULINIFOLIAB. Leaves mainly, or all, cauline. 

 I. TRICHOSTACHTAE. Bracts mainly with long filiform tips. 



a. Arkansanae. Heads large, sometimes 2}^ cm. high, 



50-70 flowered. 



1. V. crinita Raf. {V. Arkansana DC.]. Arkansas 

 ironwked. 



b. Noveboracenses. Heads medium, 15 to 40 flowered, i^ 

 cm. high or less; leaves not scabrous. 



2. Glabrous or pubescent; pappus reddish-purplish. V. 

 Noveboracensis (L.) WiUd. Nevi^ York iron- 

 weed. Massachusetts to Minnesota; Georgia to 

 Missouri. 



3. Tomentulose; pappus straw-colored. V. tomentosa 

 (Walt.) Ell. [K. Noveboracensis tomentosa (Walt.) 

 Britton]. Tomentose ironweed. New Jersey and 

 Pennsylvania to North Carolina. 



c. Scaberrimae. Heads small to medium; leaves scabrous 

 above. 



4. Leaves sharply dentate; tips of bracts gradually taper- 

 ing into erect awns. V. Harperi Gleason. Harper's 

 ironweed. Georgia. 



5. Leaves coarsely toothed; subulate tips of bracts soft. 

 V. pulchella Small. Showy ironweed. Georgia. 



6. Leaves entire or remotely toothed; subulate tips of 

 bracts rigid. V. SCaberrima Nutt. \y. angustifolia 

 5ca5err;'/«« (Nutt.) Gray]. Harsh ironweed. South 

 Carolina to Florida. 



7. Leaves entire or remotely toothed; subulate tips of 

 bracts recurved. V. recul'va Gleason. Recurve- 

 bracted ironweed. Georgia. 



n. BRACHYSTACHYBAE. Bracts mainly without filiform tips. 

 O- Platyphyllae. Leaves lanceolate to oval, not linear, 

 a. Baldwiniae. Bracts with attenuate recurved tips. 



8. Bracts ovate; pappus red-purple; inflorescence cymose; 

 leaves ovate-lanceolate; heads medium. V. Bald- 

 winii Torr. V. interior Baldivinii (Torr.) Mack & 

 Bush. Baldwin's ironweed. 



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