OF AETS AND SCIENCES. 203 



Tanacetum Linn. On account of the corymbose heads and broad 

 abrupt summit of the achenium, the following must be transferred to 

 this genus : — 



in the present plant is not " obtusiusculis breviter aristatis." I do not find it 

 among Berlandier's reUquice here ; and tliat species, as ah-eadj stated, was founded 

 mainly on Berlandier's no. 2113, which is 11. microcephaluin. 



•1- -1- I- Pappus raediocris vel majusculus, e paleis latis costa pi. m. perspicua 

 percursis mucrouatis aristatis vel acuminatis; receptaculum semi- vel sub- 

 globosum, 



♦+ rdia lanceolata seu lanceolatodinearia, ima oblanceolata seu oblongo-spatliu- 

 lata : discus globosus. 



6. H. Mexicanum HBK. Foliis subintegerrimis ; capitulis corymbosis . 

 breviuscule pedunculatis ; ligulis disco brevioribus ; pappi paleis ovatis tenuiter 

 apiculatis seu aristellatis costa subevanida percursis corolla 2-3-plo brevioribus. 

 — H. variuin Schrader ; DC. Prodr. 1. c. "? Mexico. — Kunth does not mention 

 the size of the pappus, either absolutely or relatively to the corolla; but in his 

 specimen it is actually almost half the length of the disk-corolla ; so that De 

 CandoUe's plant with pappus only one-fifth of the lengtli of the disk-corolla is 

 something else ; and his as well as Schrader's 11. varium is probably the true 

 H. Mexicunum, — to which belong Andrieux's no. 190, and Hartweg's 130. 



6. H. LACiNiATUM. Huniile, cinereo-puberulum ; foliis saspius pinnatifido- 

 dentatis vel incisls ; capitulis sparsis longe pedunculatis ; ligulis disco dimidio 

 brevioribus ; pappi paleis ovatis in aristam corolla paullo breviorem subito an- 

 gustatis. — California (probably on the southeastern borders), Coulter, no. 356, 

 3-58. Yaqui River, near the eastern side of the Gulf of California, in Sonora, 

 Dr. E. Palmer. 



7. H. PUBERULrM DC. Elatum, paniculato-ramosum ; foliis integerrirais ; 

 capitulis longe pedunculatis; ligulis disco dimidio vel multo brevioribus saepe 

 inconspicuis ; pappi paleis ovatis breviter aristatis corolla 8-4-plo brevioribus. 



.M- 4-1- Folia angustissime linearia, innumera : discus globosus, ligulis sat magnis 

 superatus. 



8. H. TENUiFOLiuM Nutt. — Mississippi to Texas. Clearly the root is not 

 perennial. The pappus is produced into long and capillary awns. 



* * Perennia, surculis radicalibus biennibus renovata : pappi paleae integrae vel 

 eroso-denticulatse, pi. m. acuminato-aristatas : ligulae discum globosum vel 

 subdepressum gequantes saepiusve superantes. 



+- Neutri, rarius styliferse steriles : receptaculum ovoideum. 



9. H. NUDiFLORUM Nutt. H. nudifloruiii, viicranthum, et parvijiorum Nutt. in 

 Trans. Am. Phil. Soc. n. ser. 7, p. 384, 385. H. Seminarieme Featherman, in 

 Louisiana Geol. Rep. Leptopoda brachi/})oda Torr. & Gray. — Var. purpurea, if. 

 atropwpureum Kunth, Ind. Sem. Berd. 1845, p. 21. — Delaware 1 to Ilhnois and 

 Texas. Varies with flowers all yellow, or the disk brown purple, or the rays 

 partly or almost wholly brown purple. H. parvijiorum Nutt. from Georgia, in 

 tny authentic specimen, has wholly neutral rays, and is manifestly of this spe- 



